Should We Terraform Mars? A Debate

This is a part of a debate organised by NASA. Science Fiction Meets Science Fact. ‘What are the real possibilities, as well as the potential ramifications, of transforming Mars?’ Terraform debaters left to right, Greg Bear , author of such books as “Moving Mars” and “Darwin’s Radio.”; David Grinspoon , planetary scientist at the Southwest Research Institute; James Kasting , geoscientist at Pennsylvania State University; Christopher McKay , planetary scientist at NASA Ames Research Center.; Lisa Pratt , biogeochemist at Indiana University; Kim Stanley Robinson , author of the “Mars Trilogy” (“Red Mars,” “Green Mars” and “Blue Mars“); John Rummel , planetary protection officer for NASA; moderator Donna Shirley , former manager of NASA’s Mars Exploration Program at the Jet Propulsion Laboratory.

Donna Shirley: Greg, what are the ethics of exploring Mars?

Greg Bear: You usually talk about ethics within your own social group. And if you define someone as being outside your social group, they’re also outside your ethical system, and that’s what’s caused so much trauma, as we seem to be unable to recognize people who look an awful lot like us as being human beings.

When we go to Mars, we’re actually dealing with a problem that’s outside the realm of ethics and more in the realm of enlightened self-interest. We have a number of reasons for preserving Mars as it is. If there’s life there, it’s evolved over the last several billion years, it’s got incredible solutions to incredible problems. If we just go there and willy-nilly ramp it up or tamp it down or try to remold it somehow, we’re going to lose that information. So that’s not to our best interest.

We were talking earlier about having a pharmaceutical expedition to Mars, not just that but a chemical expedition to Mars, people coming and looking for solutions to incredible problems that could occur here on Earth and finding them on Mars. That could generate income unforeseen.

If we talk about ethical issues on a larger scale of how are other beings in the universe going to regard how we treat Mars, that’s a question for Arthur C. Clarke to answer, I think. That’s been more his purview: the large, sometimes sympathetic eye staring at us and judging what we do.

We really have to look within our own goals and our own heart here. And that means we have to stick within our social group, which at this point includes the entire planet. If we decide that Mars is, in a sense, a fellow being, that the life on Mars, if we discover them – and I think that we will discover that Mars is alive – is worthy of protection, then we have to deal with our own variations in ethical judgment.

“I’ve heard a lot of people say, ‘Why should we go to Mars, because look at what human beings have done to Earth.'” -David Grinspoon Image Credit: NASA

The question is, if it’s an economic reality that Mars is extraordinarily valuable, will we do what we did in North America and Africa and South America and just go there and wreak havoc? And we have to control our baser interests, which is, as many of us have found out recently, very hard to do in this country. So we have a lot of problems to deal with here, internal problems. Because not everyone will agree on an ethical decision and that’s the real problem with making ethical decisions.

Donna Shirley: David, you want to comment on the ethics of terraforming Mars?

David Grinspoon: Well, one comment I’ve heard about recently, partly in response to the fact that the president has recently proposed new human missions to Mars – of course, that’s not terraforming, but it is human activities on Mars – and I’ve heard a lot of people say, “Why should we go to Mars, because look at what human beings have done to Earth. Look at how badly we’re screwing it up. Look at the human role on Earth. Why should we take our presence and go screw up other places?”

It’s an interesting question, and it causes me to think about the ethics of the human role elsewhere. What are we doing in the solar system, what should we be doing? But, it’s very hard for me to give up on the idea. Maybe because I read too much science fiction when I was a kid, I do have, I have to admit, this utopian view of a long-term human future in space. I think that if we find life on Mars, the ethical question’s going to be much more complicated.

But in my view, I think we’re going to find that Mars does not have life. We may have fossils there. I think it’s the best place in the solar system to find fossils. Of course, I could be wrong about this and I’d love to be wrong about it, and that’s why we need to explore. If the methane observation is borne out, it would be, to me, the first sign that I really have to rethink this, that maybe there is something living there under the ice.

“If the methane observation is borne out, maybe there is something living there under the ice.” -David Grinspoon Image Credit: NASA

But let’s assume for a second that Mars really is dead, and we’ve explored Mars very carefully – and this is not a determination we’ll be able to make without a lot more exploration – but assuming it was, then what about this question. Should human beings go to Mars, because do we deserve to, given what we’ve done to Earth? And to me, the analogy is of a vacant lot versus planting a garden. If Mars is really dead, then to me it’s like a vacant lot, where we have the opportunity to plant a garden. I think, in the long run, that we should.

We’ve heard a lot different possible motivations, economic motivations, or curiosity, but I think ultimately the motivation should be out of love for life, and wanting there to be more life where there’s only death and desolation. And so I think that ethically, in the long run, if we really learn enough to say that Mars is dead, then the ethical imperative is to spread life and bring a dead world to life.

Donna Shirley: Jim, we can’t prove a negative, so how do we know if there’s life or not, if we keep looking and looking and looking. How long should we look? How would we make that decision?

James Kasting: I think Lisa put us on the right track initially. She’s studying subsurface life on Earth. If there’s life on Mars today, it’s subsurface. I think it’s deep subsurface, a kilometer or two down. So I think we do need humans on Mars, because we need them up there building big drilling rigs to drill down kilometers depth and do the type of exploration that Lisa and her group is doing on Earth here. I think that’s going to take not just decades, but probably a couple of centuries before we can really get a good feel for that.

Lake Vostok. Image Credit: NASA

Donna Shirley: Well, I know, John, at Lake Vostok, one of the big issues is, if we drill into it, our dirty drilling rigs are going to contaminate whatever’s down there. So how do we drill without worrying about contaminating something if it is there?

John Rummel: Well, you accept a little contamination probabilistically that you can allow operations and still try to prevent it. I mean, basically what we can do is try to prevent that which we don’t want to have happen. We can’t ever have a guarantee. The easiest way to prevent the contamination of Mars is to stay here in this room. Or someplace close by.

Greg Bear: That’s known as abstinence.

John Rummel: [laughs]. I also want to point out it’s not necessarily the case that the first thing you want to do on Mars, even if there’s no life, is to change it. We don’t know the advantages of the martian environment. It’s a little bit like the people who go to Arizona for their allergies and start planting crabgrass right off. They wonder why they get that. And it may be that Mars as it is has many benefits. I started working here at NASA Ames as a postdoc with Bob McElroy on controlled ecological life-support systems. There’s a lot we can do with martian environments inside before we move out to the environment of Mars and try to mess with it. So I would highly recommend that not only do we do a thorough job with robotic spacecraft on Mars, but we do a thorough job living inside and trying to figure out what kind of a puzzle Mars presents.

The ALH Meteorite. Image Credit: NASA/ Johnson Space Center

Donna Shirley: Stan, you dealt with this issue in your book with the Reds versus the Greens. What are some of the ethics of making decisions about terraforming Mars?

Kim Stanley Robinson: Ah, the Reds versus the Greens. This is a question in environmental ethics that has been completely obscured by this possibility of life on Mars.

After the Viking mission, and for about a decade or so, up to the findings of the ALH meteorite, where suddenly martian bacteria were postulated again, we thought of Mars as being a dead rock. And yet there were still people who were very offended at the idea of us going there and changing it, even though it was nothing but rock. So this was an interesting kind of limit case in environmental ethics, because this sense of what has standing. People of a certain class had standing, then all the people had standing, then the higher mammals had standing – in each case it’s sort of an evolutionary process where, in an ethical sense, more and more parts of life had standing, and need consideration and ethical treatment from us. They aren’t just there to be used.

• See terraforming image gallery and martian topographical renderings

When you get to rock, it seemed to me that there would be very few people (wanting to preserve it). And yet, when I talked about my project, when I was writing it, it was an instinctive thing, that Mars has its own, what environment ethicists would call, “intrinsic worth,” even as a rock. It’s a pretty interesting position. And I had some sympathy for it, because I like rocky places myself. If somebody proposed irrigating and putting forests in Death Valley, I would think of this as a travesty. I have many favorite rockscapes, and a lot of people do.

So, back and forth between Red and Green, and one of the reasons I think that my book was so long was that it was just possible to imagine both sides of this argument for a very long time. And I never really did reconcile it in my own mind except that it seemed to me that Mars offered the solution itself. If you think of Mars as a dead rock and you think it has intrinsic worth, it should not be changed, then you look at the vertical scale of Mars and you think about terraforming, and there’s a 31-kilometer difference between the highest points on Mars and the lowest. I reckoned about 30 percent of the martian surface would stay well above an atmosphere that people could live in, in the lower elevations. So maybe you could have it both ways. I go back and forth on this teeter-totter. But of course now it’s a kind of an older teeter-totter because we have a different problem now.

Links: Colonization of mars[Are We Going To Colonize Mars?]

Stardust NExT: Mission to Comet Tempel 1

A bonus round is something one usually associates with the likes of a TV game show, not a pioneering deep space mission. “We are definitely in the bonus round,” said Stardust-NExT Project Manager Tim Larson of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “This spacecraft has already flown by an asteroid and a comet, returned comet dust samples to Earth, and now has almost doubled its originally planned mission life. Now it is poised to perform one more comet flyby.”

Could comets have brought water to Earth?

Comets preserve important clues to the early history of the solar system. They are believed to have contributed some of the volatiles that make up our oceans and atmosphere. They may even have brought to Earth the complex molecules from which life arose. For these reasons, the Committee on Planetary and Lunar Exploration (COMPLEX) has emphasized the direct exploration of comets by spacecraft. The investigation of comets also addresses each of the three strategic objectives for solar system exploration enunciated in NASA’s Space Science Enterprise Strategy (SSES) 2003.

– To learn how the solar system originated and evolved to its current state.
– To understand how life begins and determine the characteristics of the solar system that led to the origin of life.
– To catalog and understand the potential impact hazard to Earth from space.

The Stardust-NExT mission will contribute significantly to the first and last of these objectives by obtaining essential new data on Tempel 1 and capitalize on the discoveries of earlier missions such as Deep Impact to determine how cometary nuclei were constructed at the birth of the solar system and increase our understanding of how they have evolved since then. The Stardust-NExT mission provides NASA with the unique opportunity to study two entirely different comets with the same instrument. By doing this scientist will be able to more accurately compare its existing data set.

The primary science objectives of the mission are as follows:

• To extend our understanding of the processes that affect the surfaces of comet nuclei by documenting the changes that have occurred on comet Tempel 1 between two successive perihelion passages.
• To extend the geologic mapping of the nucleus of Tempel 1 to elucidate the extent and nature of layering and help models of the formation and structure of comet nuclei.
• To extend the study of smooth flow deposits, active areas, and known exposure of water ice.
• On February 14, 2011, at a projected distance of 200 km, the Stardust-NExT spacecraft will obtain high-resolution images of the coma and nucleus, as well as measurements of the composition, size distribution and flux of dust emitted into the coma. Additionally, Stardust-NExT will update the data gathered in 2005 by the Deep Impact mission on the rotational phase of the comet.

Other Objectives:

• If possible, to characterize the crater produced by Deep Impact in July 2005 to better understand the structure and mechanical properties of cometary nuclei and elucidate crater formation processes on them.
• Measure the flux and mass distribution of dust particles within the coma using the DFMI instrument.
• Analyze the composition of dust particles within the coma using the CIDA instrument.
• Monitor comet activity over 60 days on approach using imaging.

Artist concept of NASA's Stardust-NExT mission, which will fly by comet Tempel 1 on Feb. 14, 2011.

A Successful Prime Mission

NASA’s Stardust spacecraft was launched on Feb. 7, 1999, on a mission that would explore a comet as no previous mission had. Before Stardust, seven spacecraft from NASA, Russia, Japan and the European Space Agency had visited comets – they had flight profiles that allowed them to perform brief encounters, collecting data and sometimes images of the nuclei during the flyby.

Like those comet hunters before it, Stardust was tasked to pass closely by a comet, collecting data and snapping images. It also had the ability to come home again, carrying with it an out-of -this-world gift for cometary scientists – particles of the comet itself. Along the way, the telephone booth-sized comet hunter racked up numerous milestones and more than a few “space firsts.”

In the first round of its prime mission, Stardust performed observations of asteroid Annefrank, only the sixth asteroid in history to be imaged close up. After that, Stardust racked up more points of space exploration firsts. It became the first spacecraft to capture particles of interstellar dust for Earth return. It was first to fly past a comet and collect data and particles of comet dust (hurtling past it at almost four miles per second) for later analysis. Then, it was first to make the trip back to Earth after traveling beyond the orbit of Mars (a two-year trip of 1.2 billion kilometers, or 752 million miles). When Stardust dropped off its sample return capsule from comet Wild 2, the capsule became the fastest human-made object to enter Earth’s atmosphere. The mission was also the first to provide a capsule containing cometary dust specimens, speciments that will have scientists uncovering secrets of comets for years to come.

With such a high tally of “firsts” on its scoreboard, you’d think Stardust could receive a few parting gifts and leave the game. And an important part of the original spacecraft is currently enjoying retirement – albeit a high-profile one: Stardust’s 100-pound sample return capsule is on display in the main hall (Milestones of Flight) of the Smithsonian’s National Air and Space Museum in Washington. But the rest of NASA’s most-seasoned comet hunter is still up there – and there is work still to be done.

“We placed Stardust in a parking orbit that would carry it back by Earth in a couple of years, and then asked the science community for proposals on what could be done with a spacecraft that had a lot of zeros on its odometer, but also had some fuel and good miles left in it,” said Jim Green, director of NASA’s Planetary Science Division.

Moving into the Bonus Round

In January 2007, from a stack of proposals with intriguing ideas, NASA chose Stardust-NExT (Stardust’s Next Exploration of Tempel). It was a plan to revisit comet Tempel 1 at a tenth of the cost of a new, from-the-ground-up mission. Comet Tempel 1 was of particular interest to NASA. It had been the target of a previous NASA spacecraft visit in July 2005. That mission, Deep Impact, placed a copper-infused, 800-pound impactor on a collision course with the comet and observed the results from the cosmic fender-bender via the telescopic cameras onboard the larger part of Deep Impact, a “flyby” spacecraft observing from a safe distance.

“The plan for our encounter is to be more hospitable to comet Tempel 1 than our predecessor,” said Joe Veverka, principal investigator of Stardust-NExT from Cornell University in Ithaca, N.Y. “We will come within about 200 kilometers [124 miles] of Tempel 1 and view the changes that took place over the past five-and-a-half years.”

That period of time is significant for Tempel 1 — it is the period of time it takes the comet to orbit the sun once. Not much happens during a comet’s transit through the chilly reaches of the outer solar system. But when it nears perihelion (the point in its orbit that an object, such as a planet or a comet, is closest to the sun), things begin to sizzle.

“Comets can be very spectacular when they come close to the sun, but we still don’t understand them as well as we should,” said Veverka. “They are also messengers from the past. They tell us how the solar system was formed long ago, and Stardust-NExT will help us understand how much they have changed since their formation.”

So the spacecraft that had traveled farther afield than any of its predecessors was being sent out again in the name of scientific opportunity. In between spacecraft and comet lay four-and-a-half years, over a billion kilometers (646 million miles), and more than a few hurdles along the way.

Your Mileage May Vary

“One of the challenges with reusing a spacecraft designed for a different prime mission is you don’t get to start out with a full tank of gas,” said Larson. “Just about every deep-space exploration spacecraft has a fuel supply customized to get the job done, with some held in reserve for contingency maneuvers and other uncertainties. Fortunately, the Stardust mission navigation team did a great job, the spacecraft operated extremely well, and there was an adequate amount of contingency fuel aboard after its prime mission to make this new comet flyby possible – but just barely.”

Just how much fuel is in Stardust’s tanks for its final act?

“We estimate we have a little under three percent of the fuel the mission launched with,” said Larson. “It is an estimate, because no one has invented an entirely reliable fuel gauge for spacecraft. There are some excellent techniques with which we have made these estimates, but they are still estimates.”

One of the ways mission planners can approximate fuel usage is to look at the history of the vehicle’s flight and how many times and for how long its rocket motors have fired. When that was done for Stardust, the team found their spacecraft’s attitude and translational thrusters had fired almost half-a-million times each over the past 12 years.

“There is always a little plus and minus with each burn. When you add them all up, that is how you get the range of possible answers on how much fuel was used,” said Larson.

Fuel is not the only question that needs to be addressed on the way to a second comet encounter. Added into the mix is the fact a comet near the sun can fire off jets of gas and dust that can cause a change in its orbit, sometimes in unexpected ways, potentially causing a precisely designed cometary approach to become less precise. Then there are the distances involved. Stardust will fly past comet Tempel 1 on almost the opposite side of the sun from Earth, making deep-space communication truly, well, deep space. Add into the mix the Stardust spacecraft itself. Launched when Bill Clinton was in the White House, Stardust has been cooked and frozen countless times during its trips from the inner to outer solar system. It has also weathered its fair share of radiation-packed solar storms. But while its fuel tank may be running near-empty, that doesn’t mean Stardust doesn’t have anything left in the tank.

“All this mission’s challenges are just that – challenges,” said Larson. “We believe our team and our spacecraft are up to meeting every one of them, and we’re looking forward to seeing what Tempel 1 looks like these days.”

The Final Payoff

Larson, Veverka and the world will get their chance beginning a few hours after the encounter on Monday, Feb. 14, at about 8:56 p.m. PST (11:56 p.m. EST), when the first of 72 bonus-round images of the nucleus of comet Tempel 1 are downlinked.

All images of the comet will be taken by the spacecraft’s navigation camera – an amalgam of spare flight-ready hardware left over from previous NASA missions: Voyager (launched in 1977), Galileo (launched in 1989), and Cassini (launched in 1997). Each image will take about 15 minutes to transmit. The first five images to be received and processed on the ground are expected to include a close up of Tempel 1’s nucleus. All data from the flyby (including the images and science data obtained by the spacecraft’s two onboard dust experiments) are expected to take about 10 hours to reach the ground. Stardust-NExT is a low-cost mission that will expand the investigation of comet Tempel 1 initiated by NASA’s Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for the NASA Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission’s principal investigator. Lockheed Martin Space Systems, Denver Colo., built the spacecraft and manages day-to-day mission operations.

Mission Details

The Stardust-NExT will utilize the existing spacecraft to flyby comet Tempel 1 and observe changes since NASA’s Deep Impact mission visited it in 2005. Stardust-NExT will provide NASA with a first-time opportunity to compare observations of a single comet made at close range during two successive perihelion passages, at low risk and low cost.

In 2005, Tempel 1 made its closest approach to the sun, possibly changing the surface of the comet. With a 3-year trajectory, the mission flight plan is designed in a similar way to that of the original mission, with an Earth gravity assist (EGA) in 2009 to achieve the flyby of Tempel 1 in 2011. The original flight path of the Stardust spacecraft to Wild 2 included an EGA in 2001.

Mission Design and Navigation:
The Stardust spacecraft divert maneuver that followed the release of the sample return capsule (SRC) was intentionally designed to place the spacecraft in a trajectory that returns to Earth in case the SRC release that occurred January 15 had failed. Thus the current orbit intrinsically provides the Earth gravity-assist (EGA) flyby opportunity in 2009, which enables the Tempel 1 encounter. The mission duration, from the divert maneuver after SRC release (January 15, 2006) to the February 14, 2011 Tempel 1 encounter, is a little over 5 years. The date of encounter will be optimized during the mission to account for improved knowledge of the comet’s ephemeris during cruise, and to maximize the probability of viewing the Deep Impact impact crater. Table F-1 summarizes the principal characteristics of the comet encounter.

Table F-1. Tempel 1 Encounter Characteristics
Flyby date	February 14, 2011
Distance	200 km
Velocity	10.9 km/s
Approach Phase angle	81.6°
Closest Approach Point	200 km altitude, 40° south of direction to the Sun
Solar Distance	1.55 AU
Earth Distance	2.25 AU

Mission Trajectory:
The trajectory consists of four loops of the sun in two separate orbits. Loops 1 and 2 represent the orbit the spacecraft bus was left in after the sample return on January 15, 2006. The EGA on January 14, 2009 places the spacecraft in the final heliocentric orbit (Loops 3 and 4) intercepting Tempel 1 on February 14, 2011 (39d after the comet’s perihelion). This profile is very similar to the launch-to-Wild 2 phase of the Stardust primary mission.

Figure F-1. Stardust-NExT trajectory, with one EGA prior to Tempel 1 encounter, provides for an uncomplicated mission simpler than the Stardust prime mission.

The maneuver plan is shown in Table F-2. Of the three deep space maneuvers (DSM’s), only the first is deterministic. This maneuver targets the EGA in January, 2009. Other DSM’s adjust the arrival time at Tempel 1. Ranges of favorable locations for DSMs (2 and 3) are indicated. Their exact location will be optimized during the mission.

Table F-2. Maneuver plan targets EGA and Tempel 1 encounter with few maneuvers
Maneuver	Epoch	Comment	Execution Date (UTC)
DSM1	Entry + 603d	EGA Targeting	9/19/07
DSM1_CU	DSM1 + 30d	Cleanup	10/19/07
EGA1	E-30d	EGA Targeting	12/16/08
EGA2	E – 10d	EGA Targeting	1/5/09
EGA2a	E – 1d	EGA Targeting	1/13/09
DSM2	T1 – 1y	Arrival Time Adjust	2/12/10
DSM2_CU	DSM2 + 30d	Cleanup	3/14/10
T0	T1-120d	T1 Targeting	10/18/10
T1 (DSM3)	T1-30d	T1 Targeting	1/15/11
T2	T1 – 10d	T1 Targeting	2/4/11
T3	T1 – 2d	T1 Targeting	2/12/11
T4	T1 – 18h	T1 Targeting	2/14/11
T5	T1 – 6h	T1 Targeting (Contingency)	2/14/11

The Stardust navigation team has chosen to place the closest approach point 40° southward of the direction to the Sun, at a longitude that offers the most favorable viewing opportunity of the Deep Impact crater at closest approach. Periodically, reevaluate the aimpoint during the mission, taking into account the most recent information available about the predicted uncertainty of the comet’s rotation state at encounter, until the time shortly before DSM2 (deep space maneuver) at which a selection of a final aimpoint for targeting.

Controlling the arrival time to target our chosen aimpoint is the greatest mission design challenge of Stardust-NExT. In order to successfully control the arrival time as discussed above, two conditions must be met: (1) we must be able to predict the rotation rate and rotational state of the comet with sufficient accuracy to reliably compute the right arrival time, and (2) we must have sufficient DV onboard to change the arrival time as needed.

[Credit: NASA]

Hubble Finds Farthest Galaxy!

Image by rmforall@gmail.com via Flickr

Astronomers have pushed NASA’s Hubble Space Telescope to its limits by finding what is likely to be the most distant object ever seen in the universe. The object’s light traveled 13.2 billion years to reach Hubble, roughly 150 million years longer than the previous record holder. The age of the universe is approximately 13.7 billion years.

The tiny, dim object is a compact galaxy of blue stars that existed 480 million years after the big bang. More than 100 such mini-galaxies would be needed to make up our Milky Way. The new research offers surprising evidence that the rate of star birth in the early universe grew dramatically, increasing by about a factor of 10 from 480 million years to 650 million years after the big bang.

“NASA continues to reach for new heights, and this latest Hubble discovery will deepen our understanding of the universe and benefit generations to come,” said NASA Administrator Charles Bolden, who was the pilot of the space shuttle mission that carried Hubble to orbit. “We could only dream when we launched Hubble more than 20 years ago that it would have the ability to make these types of groundbreaking discoveries and rewrite textbooks.”

Astronomers don’t know exactly when the first stars appeared in the universe, but every step farther from Earth takes them deeper into the early formative years when stars and galaxies began to emerge in the aftermath of the big bang.

“These observations provide us with our best insights yet into the earlier primeval objects that have yet to be found,” said Rychard Bouwens of the University of Leiden in the Netherlands. Bouwens and Illingworth report the discovery in the Jan. 27 issue of the British science journal Nature.

This observation was made with the Wide Field Camera 3 starting just a few months after it was installed in the observatory in May 2009, during the last NASA space shuttle servicing mission to Hubble. After more than a year of detailed observations and analysis, the object was positively identified in the camera’s Hubble Ultra Deep Field-Infrared data taken in the late summers of 2009 and 2010.

The object appears as a faint dot of starlight in the Hubble exposures. It is too young and too small to have the familiar spiral shape that is characteristic of galaxies in the local universe. Although its individual stars can’t be resolved by Hubble, the evidence suggests this is a compact galaxy of hot stars formed more than 100-to-200 million years earlier from gas trapped in a pocket of dark matter.

“We’re peering into an era where big changes are afoot,” said Garth Illingworth of the University of California at Santa Cruz. “The rapid rate at which the star birth is changing tells us if we go a little further back in time we’re going to see even more dramatic changes, closer to when the first galaxies were just starting to form.”

The proto-galaxy is only visible at the farthest infrared wavelengths observable by Hubble. Observations of earlier times, when the first stars and galaxies were forming, will require Hubble’s successor, the James Webb Space Telescope (JWST).

The hypothesized hierarchical growth of galaxies — from stellar clumps to majestic spirals and ellipticals — didn’t become evident until the Hubble deep field exposures. The first 500 million years of the universe’s existence, from a z of 1000 to 10, is the missing chapter in the hierarchical growth of galaxies. It’s not clear how the universe assembled structure out of a darkening, cooling fireball of the big bang. As with a developing embryo, astronomers know there must have been an early period of rapid changes that would set the initial conditions to make the universe of galaxies what it is today.

“After 20 years of opening our eyes to the universe around us, Hubble continues to awe and surprise astronomers,” said Jon Morse, NASA’s Astrophysics Division director at the agency’s headquarters in Washington. “It now offers a tantalizing look at the very edge of the known universe — a frontier NASA strives to explore.”

Hydrotropi: A Hope for Space Colonization

A while back , I’ve published an article about explaining need to colonize mars. Last year, NASA successfully developed “alternative crops” that can be grown in space like (zero gravity) conditions.

Plants are fundamental to life on Earth, converting light and carbon dioxide into food and oxygen. Plant growth may be an important part of human survival in exploring space, as well. Gardening in space has been part of the International Space Station from the beginning — whether peas grown in the Lada greenhouse or experiments in the Biomass Production System. The space station offers unique opportunities to study plant growth and gravity, something that cannot be done on Earth.

The latest experiment that has astronauts putting their green thumbs to the test is Hydrotropism and Auxin-Inducible Gene expression in Roots Grown Under Microgravity Conditions, known as HydroTropi. Operations were conducted October 18-21, 2010, HydroTropi is a Japan Aerospace Exploration Agency (JAXA)-run study that looks at directional root growth. In microgravity, roots grow latterly or sideways, instead of up and down like they do under Earth’s gravitational forces.

[HydroTropi: Overview

Experiment/Payload Overview

Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA). Brief Summary

Hydrotropism and Auxin-Inducible Gene expression in Roots Grown Under Microgravity Conditions (HydroTropi) determines whether hydrotropic response can be used for the control of cucumber, Cucumis sativus root growth orientation in microgravity.

Principal Investigator

Hideyuki Takahashi, Ph.D., Tohoku University, Sendai, Japan

Co-Investigator(s)/Collaborator(s)

Nobuharu Fujii, Ph.D., Tohoku University, Sendai, Japan

Yutaka Miyazawa, Ph.D., Tohoku University, Sendai, Japan

Sponsoring Space Agency

Japan Aerospace Exploration Agency (JAXA)

Supporting Organization:

Information Pending

Expeditions Assigned

|25/26|

Previous ISS Missions

Increment 23/24 will be the first mission for HydroTropi operations

Experiment/Payload Description

Research Summary

The Hydrotropism and Auxin?Inducible Gene expression in Roots Grown Under Microgravity Conditions (HydroTropi) experiment has three specific aims:

• First, it demonstrates that gravitropism (a plant’s ability to change its direction of growth in response to gravity) interferes with hydrotropism (a directional growth response in which the direction is determined by a stimuli in water concentration).
• Second, it clarifies the differential auxin response that occurs during the respective tropisms (reaction of a plant to a stimulus), by investigating the auxin (compound regulating the growth of plants) inducible gene expression.
• Third, it shows whether hydrotropism can be used in controlling root growth orientation in microgravity.

Description

Hydrotropism and Auxin?Inducible Gene expression in Roots Grown Under Microgravity Conditions (HydroTropi) will propose to use the microgravity environment in space to separate hydrotropism from gravitropism and to dissect respective mechanisms in cucumber roots.]

Cucumber roots grew laterally in space following 70 hours in microgravity on STS 95. (JAXA)

Using cucumber plants (scientific name Cucumis sativus), investigators look to determine whether hydrotropic — plant root orientation due to water—response can control the direction of root growth in microgravity. To perform the HydroTropi experiment, astronauts transport the cucumber seeds from Earth to the space station and then coax them into growth. The seeds, which reside in Hydrotropism chambers, undergo 18 hours of incubation in a Cell Biology Experiment Facility orCBEF. Then the crewmembers activate the seeds with water or a saturated salt solution, followed by a second application of water 4 to 5 hours later. The crew harvests the cucumber seedlings and preserves them using fixation tubes called Kenney Space Center Fixation Tubes or KFTs, which then store in one of the station MELFI freezers to await return to Earth.
The results from HydroTropi, which returns to Earth on STS-133, will help investigators to better understand how plants grow and develop at a molecular level. The experiment will demonstrate a plant’s ability to change growth direction in response to gravity (gravitropism) vs. directional growth in response to water (hydrotropism). By looking at the reaction of the plants to the stimuli and the resulting response of differential auxin — the compound regulating the growth of plants — investigators will learn about plants inducible gene expression. In space, investigators hope HydroTropi will show them how to control directional root growth by using the hydrotropism stimulus; this knowledge may also lead to significant advancements in agriculture production on Earth.

[Credit: NASA]

Coronal Heating Mystery Explained

Among the many constantly moving, appearing, disappearing and generally explosive events in the sun’s atmosphere, there exist giant plumes of gas — as wide as a state and as long as Earth — that zoom up from the sun’s surface at 150,000 miles per hour. Known as spicules, these are one of several phenomena known to transfer energy and heat throughout the sun’s magnetic atmosphere, or corona.

Thanks to NASA’s Solar Dynamics Observatory (SDO) and the Japanese satellite Hinode, these spicules have recently been imaged and measured better than ever before, showing them to contain hotter gas than previously observed. Thus, they may perhaps play a key role in helping to heat the sun’s corona to a staggering million degrees or more. (A number made more surprising since the sun’s surface itself is only about 10,000 degrees Fahrenheit.)   Just what makes the corona so hot is a poorly understood aspect of the sun’s complicated space weather system. That system can reach Earth, causing auroral lights and, if strong enough, disrupting Earth’s communications and power systems. Understanding such phenomena, therefore, is an important step towards better protecting our satellites and power grids. Solar physicist Dean Pesnell said:

The traditional view is that all heating happens higher up in the corona.  The suggestion in this paper is that cool gas is ejected from the sun’s surface in spicules and gets heated on its way to the corona. This doesn’t mean the old view has been completely overturned, but this is a strong suggestion that part of the spicule material gets heated to very high temperatures and provides some coronal heating.

Spicules were first named in the 1940s, but were hard to study in detail until recently, says Bart De Pontieu of Lockheed Martin’s Solar and Astrophysics Laboratory, Palo Alto, Calif. whose work on this subject appears in the January 7, 2011 issue of Science magazine. In visible light, spicules can be seen to send large masses of so-called plasma – the electromagnetic gas that surrounds the sun — up through the lower solar atmosphere or photosphere. The amount of material sent up is stunning, some 100 times as much as streams away from the sun in the solar wind towards the edges of the solar system. But nobody knew if they contained hot gas.

[Image  Details:  Spicules on the sun, as observed by the Solar Dynamics Observatory. These bursts of gas jet off the surface of the sun at 150,000 miles per hour and contain gas that reaches temperatures over a million degrees. Credit: NASA Goddard/SDO/AIA]

Now, De Pontieu’s team — which included researchers at Lockheed Martin, the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) in Colorado and the University of Oslo, Norway — was able to combine images from SDO and Hinode to produce a more complete picture of the gas inside these gigantic fountains. Tracking the movement and temperature of spicules relies on successfully identifying the same phenomenon in all the images. One complication comes from the fact that different instruments “see” gas at different temperatures. Pictures from Hinode in the visible light range, for example, show only cool gas, while pictures that record UV light show gas that is up to several million degrees.

To show that the previously known cool gas in a spicule lies side by side to some very hot gas requires showing that the hot and cold gas in separate images are located in the same space. Each spacecraft offered specific advantages to help confirm that one was seeing the same event in multiple images. First, Hinode: In 2009, scientists used observations from Hinode and telescopes on Earth to, for the first time, identify a spicule when looking at it head-on. (Imagine how tough it is, looking from over 90 million miles away, to determine that you’re looking at a fountain when you only have a top-down view instead of a side view.) The top-down view of a spicule ensures an image with less extraneous solar material between the camera and the fountain, thus increasing confidence that any observations of hotter gas are indeed part of the spicule itself.

The second aid to tracking a single spicule is SDO’s ability to capture an image of the sun every 12 seconds. “You can track things from one image to the next and know you’re looking at the same thing in a different spot,” says Pesnell. “If you had an image only every 12 minutes, then you couldn’t be sure that what you’re looking at is the same event, since you didn’t watch its whole history.”

 

[Image Details: Artist’s concept of the Solar Dynamics Observatory. 05/12/08 Credit: NASA/Goddard Space Flight Center Conceptual Image Lab]

Bringing these tools together, scientists could compare simultaneous images in SDO and Hinode to create a much more complete image of spicules. They found that much of the gas is heated to a hundred thousand degrees, while a small fraction of the gas is heated to millions of degrees. Time-lapsed images show that this hot material spews high up into the corona, with much of it falling back down towards the surface of the sun. However, the small fraction of the gas that is heated to millions of degrees does not immediately return to the surface.”Given the large number of spicules on the Sun, and the amount of material in the spicules, if even some of that super hot plasma stays aloft it would make a fair contribution to coronal heating,” says Scott McIntosh from NCAR, who is part of the research team.

Of course, De Pontieu cautions that this does not yet solve the coronal heating mystery. The main result, he says, is that they’re challenging theorists to incorporate the possibility that some coronal heating occurs at lower heights in the solar atmosphere. His next step is to help figure out how much of a role spicules play by studying how spicules form, how they move so quickly, how they get heated to such high temperatures in a short time, and how much mass stays up in the corona. Astrophysicist Jonathan Cirtain, who is the U.S. project scientist for Hinode at NASA’s Marshall Space Flight Center, Huntsville, Ala. points out that incorporating such new information helps address an important question that reaches far beyond the sun. “This breakthrough in our understanding of the mechanisms which transfer energy from the solar photosphere to the corona addresses one of the most compelling questions in stellar astrophysics: How is the atmosphere of a star heated?” he says. “This is a fantastic discovery, and demonstrates the muscle of the NASA Heliophysics System Observatory, comprised of numerous instruments on multiple observatories.”

 Hinode is the second mission in NASA’s Solar Terrestrial Probes program, the goal of which is to improve understanding of fundamental solar and space physics processes. The mission is led by the Japan Aerospace Exploration Agency (JAXA) and the National Astronomical Observatory of Japan (NAOJ). The collaborative mission includes the U.S., the United Kingdom, Norway and Europe. NASA Marshall manages Hinode U.S. science operations and oversaw development of the scientific instrumentation provided for the mission by NASA, academia and industry. The Lockheed Martin Advanced Technology Center is the lead U.S. investigator for the Solar Optical Telescope on Hinode.
  
 [Source: NASA]

Growing Crops on Other Planets

Science fiction lovers aren’t the only ones captivated by the possibility of colonizing another planet. Scientists are engaging in numerous research projects that focus on determining how habitable other planets are for life. Mars, for example, is revealing more and more evidence that it probably once had liquid water on its surface, and could one day become a home away from home for humans. 

“The spur of colonizing new lands is intrinsic in man,” said Giacomo Certini, a researcher at the Department of Plant, Soil and Environmental Science (DiPSA) at the University of Florence, Italy. “Hence expanding our horizon to other worlds must not be judged strange at all. Moving people and producing food there could be necessary in the future.” 

Humans traveling to Mars, to visit or to colonize, will likely have to make use of resources on the planet rather than take everything they need with them on a spaceship. This means farming their own food on a planet that has a very different ecosystem than Earth’s. Certini and his colleague Riccardo Scalenghe from the University of Palermo, Italy, recently published a study in Planetary and Space Science that makes some encouraging claims. They say the surfaces of Venus, Mars and the Moon appear suitable for agriculture. 

Defining Soil 

The surface of Venus, generated here using data from NASA’s Magellan mission, undergoes resurfacing through weathering processes such as volcanic activity, meteorite impacts and wind erosion. Credit: NASA

Before deciding how planetary soils could be used, the two scientists had to first explore whether the surfaces of the planetary bodies can be defined as true soil. 

“Apart from any philosophical consideration about this matter, definitely assessing that the surface of other planets is soil implies that it ‘behaves’ as a soil,” said Certini. “The knowledge we accumulated during more than a century of soil science on Earth is available to better investigate the history and the potential of the skin of our planetary neighbors.” 

One of the first obstacles in examining planetary surfaces and their usefulness in space exploration is to develop a definition of soil, which has been a topic of much debate. 

“The lack of a unique definition of ‘soil,’ universally accepted, exhaustive, and (one) that clearly states what is the boundary between soil and non-soil makes it difficult to decide what variables must be taken into account for determining if extraterrestrial surfaces are actually soils,” Certini said. 

At the proceedings of the 19th World Congress of Soil Sciences held in Brisbane, Australia, in August, Donald Johnson and Diana Johnson suggested a “universal definition of soil.” They defined soil as “substrate at or near the surface of Earth and similar bodies altered by biological, chemical, and/or physical agents and processes.” 

The surface of the Moon is covered by regolith over a layer of solid rock. Credit: NASA

On Earth, five factors work together in the formation of soil: the parent rock, climate, topography, time and biota (or the organisms in a region such as its flora and fauna). It is this last factor that is still a subject of debate among scientists. A common, summarized definition for soil is a medium that enables plant growth. However, that definition implies that soil can only exist in the presence of biota. Certini argues that soil is material that holds information about its environmental history, and that the presence of life is not a necessity. 

“Most scientists think that biota is necessary to produce soil,” Certini said. “Other scientists, me included, stress the fact that important parts of our own planet, such as the Dry Valleys of Antarctica or the Atacama Desert of Chile, have virtually life-free soils. They demonstrate that soil formation does not require biota.” 

The researchers of this study contend that classifying a material as soil depends primarily on weathering. According to them, a soil is any weathered veneer of a planetary surface that retains information about its climatic and geochemical history. 

On Venus, Mars and the Moon, weathering occurs in different ways. Venus has a dense atmosphere at a pressure that is 91 times the pressure found at sea level on Earth and composed mainly of carbon dioxide and sulphuric acid droplets with some small amounts of water and oxygen. The researchers predict that weathering on Venus could be caused by thermal process or corrosion carried out by the atmosphere, volcanic eruptions, impacts of large meteorites and wind erosion. 

Using the method of aeroponics, space travelers will be able to grow their own food without soil and using very little water. Credit: NASA

Mars is currently dominated by physical weathering caused by meteorite impacts and thermal variations rather than chemical processes. According to Certini, there is no active volcanism that affects the martian surface but the temperature difference between the two hemispheres causes strong winds. Certini also said that the reddish hue of the planet’s landscape, which is a result of rusting iron minerals, is indicative of chemical weathering in the past. 

On the Moon, a layer of solid rock is covered by a layer of loose debris. The weathering processes seen on the Moon include changes created by meteorite impacts, deposition and chemical interactions caused by solar wind, which interacts with the surface directly. 

Some scientists, however, feel that weathering alone isn’t enough and that the presence of life is an intrinsic part of any soil. 

“The living component of soil is part of its unalienable nature, as is its ability to sustain plant life due to a combination of two major components: soil organic matter and plant nutrients,” said Ellen Graber, researcher at the Institute of Soil, Water and Environmental Sciences at The Volcani Center of Israel’s Agricultural Research Organization. 

One of the primary uses of soil on another planet would be to use it for agriculture—to grow food and sustain any populations that may one day live on that planet. Some scientists, however, are questioning whether soil is really a necessary condition for space farming. 

Soilless Farming – Not Science Fiction 

With the Earth’s increasing population and limited resources, scientists are searching for habitable environments on places such as Mars, Venus and the Moon as potential sites for future human colonies. Credit: NASA

Growing plants without any soil may conjure up images from a Star Trek movie, but it’s hardly science fiction. Aeroponics, as one soilless cultivation process is called, grows plants in an air or mist environment with no soil and very little water. Scientists have been experimenting with the method since the early 1940s, and aeroponics systems have been in use on a commercial basis since 1983. 

“Who says that soil is a precondition for agriculture?” asked Graber. “There are two major preconditions for agriculture, the first being water and the second being plant nutrients. Modern agriculture makes extensive use of ‘soilless growing media,’ which can include many varied solid substrates.” 

In 1997, NASA teamed up with AgriHouse and BioServe Space Technologies to design an experiment to test a soilless plant-growth system on board the Mir Space Station. NASA was particularly interested in this technology because of its low water requirement. Using this method to grow plants in space would reduce the amount of water that needs to be carried during a flight, which in turn decreases the payload. Aeroponically-grown crops also can be a source of oxygen and drinking water for space crews. 

“I would suspect that if and when humankind reaches the stage of settling another planet or the Moon, the techniques for establishing soilless culture there will be well advanced,” Graber predicted. 

Soil: A Key to the Past and the Future 

The Mars Phoenix mission dug into the soil of Mars to see what might be hidden just beneath the surface. Credit:NASA/JPL-Caltech/University of Arizona/Texas A&M University

The surface and soil of a planetary body holds important clues about its habitability, both in its past and in its future. For example, examining soil features have helped scientists show that early Mars was probably wetter and warmer than it is currently. 

“Studying soils on our celestial neighbors means to individuate the sequence of environmental conditions that imposed the present characteristics to soils, thus helping reconstruct the general history of those bodies,” Certini said. 

In 2008, NASA’s Phoenix Mars Lander performed the first wet chemistry experiment using martian soil. Scientists who analyzed the data said the Red Planet appears to have environments more appropriate for sustaining life than was expected, environments that could one day allow human visitors to grow crops. 

“This is more evidence for water because salts are there,” said Phoenix co-investigator Sam Kounaves of Tufts University in a press release issued after the experiment. “We also found a reasonable number of nutrients, or chemicals needed by life as we know it.” 

Researchers found traces of magnesium, sodium, potassium and chloride, and the data also revealed that the soil was alkaline, a finding that challenged a popular belief that the martian surface was acidic. 

This type of information, obtained through soil analyses, becomes important in looking toward the future to determine which planet would be the best candidate for sustaining human colonies.

[Credit: Astrobiology Magazine]

Carnival of Space #179

Welcome to the carnival of space #179. If you have no idea what a carnival of space is, you can hit this page at Universe Today.

Imagine however a lunar base derived from S-IVB lander stages, as mentioned above. Each station would be the colonizable equivalent of Skylab on the ground– coverable with lunar regolith for radiation protection. With two men landing in the S-IVB, a very minimal 2 man personal reentry vehicle, imagine a version of the MOOSE (upper right) and a small two stage booster (perhaps the equivalent of the LESS on top of the MOBEV, see top center) with one of the reentry protection concepts from upper right, about 3.5 tons of the landed 7 ton payload would be the direct up return craft and reentry vehicle, (this is only HALF the weight of the 3 man Command Module alone that actually flew!) the rest supplies for expedition and colonizing the LASS lander.

Joseph Friedlander at Next Big Future site, talks about What was the best way to use the Saturn V to reach the Moon– in retrospect? An excellent discussion. Mr. Brian Wang discusses Vasimr 200 kilowatt plasma rocket achieves full power milestone.

To celebrate Mars Express’ recent mission extension to 2014, here[At Planetary Blog] are some cool pictures that it took of Mars’ inner and larger moon Phobos.

Steve Nerlich at Cheap Astronomy exudes a podcast on the origin of the oceans.

Online Schools hosts an article about space resources and also an introduction to black holes.

November 23rd, astronomers from the Asiago Novae and Symbiotic Stars collaboration announced recent changes in the symbiotic variable star, AX Persei, could indicate the onset of a rare eruption of this system. The last major eruption took place between 1988 and1992. In the (northern hemisphere) spring of 2009, AX Per underwent a short outburst that was the first time since 1992 this star had experienced a bright phase. Now AX Per is on the rise again. This has tempted astronomers to speculate that another major eruption could be in the making.

The AAVSO light curve of AX Persei from 1970 to November 2010. In the middle is the eruption of 1988-1992. The precursor outburst is the sudden narrow brightening left of the larger eruption. To the right of the light curve you can see the 2009 brightening event. Is this a precursor to a coming major eruption?

Symbiotic variable stars are binary systems whose members are a hot compact white dwarf in a wide orbit around a cool giant star. The orbital periods of symbiotic variables are between 100 and 2000 days. Unlike dwarf novae, compact binaries whose periods are measured in hours, where mass is transferred directly via an accretion disk around the white dwarf, siphoned directly from the surface of the secondary, in symbiotic variables the pair orbit each other far enough away that the mass exchanged between them comes from the strong stellar wind blowing off the red giant. Both stars reside within a shared cloud of gas and dust called a common envelope.

You can find more about it on Mike Simonsen’s blog Simostronomy.

Jupiter’s missing  belt to return? by Ian Musgrave

Cepheids are not such eclipsing binaries, being intrinsically variable, that is their fluctuating brightness comes from some process inside them. Cepheids literally shrink as they dim and swell as they brighten. In 1908,  Henrietta Swan Leavitt (1864-1921) discovered that Cepheids pulse at a rate governed by their brightness. This discovery, published in 1912, was based on painstaking measurements of 1777 stars’ characteristics recorded at Harvard College Observatory when Leavitt was employed as a ‘calculator’, a lowly paid female astronomer who performed mathematical calculations for the Observatory’s research staff. Sadly she received little credit for her work on Cepheids during her lifetime.

Colin Johnston has a excellent article on Cepheids which are massive, pulsating stars, valued by astronomers for the precise link between their brightness and steady pulsation. Let’s look at the history of Cepheid variables and how recent discoveries about these stars shatter established theories of stellar evolution.

The WISE mission has received a lot of press in terms of discovering nearby brown dwarfs, but it’s clear that finding low-temperature objects is a major investigation at many Earth-bound sites as well. That includes the UKIRT (United Kingdom Infrared Telescope) Deep Sky Survey’s project to find the coolest objects in our galaxy, an effort that has paid off in the form of a unique binary system. One of the stars here is a cool, methane-rich T-dwarf, while the other is a white dwarf, the two low-mass stars orbiting each other though separated by a quarter of a light year.

The twin objects are now known as LSPM 1459+0857 A and B, a binary that has held together despite the perturbations of the white dwarf’s history and the system’s own passage through the galactic disk. The paper notes that “This system is an example of how wide BD binary companions to white dwarfs make good benchmark objects, which will help test model atmospheres, and may provide independent means to calibrate BD properties of field objects.

Paul Gilster elucidates  some fascinating features of  Brown Dwarfs. Visit it at Centauri Dreams.

The Docrtine of  Mutually Assured Exclusion, and what will happen to our dreams of being a spacefaring civilization if we blow up each others’ satellites during a war and the resulting debris field that will prevent *anyone* from leaving Earth for a long time to come…

It’s a MAE MAE MAE MAE MAE MAE World…. by Shubber of  Space Cynics Blog

It’s a good news for space geeks. US Postal Service revealed designs for 2011 space stamps. The stamp’s design, which was quietly released last week by the U.S. Postal Service (USPS), shows Shepard from his shoulders up centered between images of his rocket lifting off and his capsule above the Earth. The pair — or “se-tenant” — of space-themed stamps was revealed in the USPS’s annual report for 2010, which was posted to the postal service’s website Nov. 15. The two stamps are displayed with other commemoratives planned for next year as a lead in to the report’s financial section.

You can find out more about it HERE.

What might we see at Santa Maria..? BY Stuart Atkinson |The Road To Endeavour

Despite uncertainties in budget, Lockheed engineers are still thinking of
missions for the Orion Crew Exploration Vehicle.  One possible mission would
take Orion to the Earth-Moon L2 point: Far side of the moon by Louise Riofrio

Another plan being discussed would launch Orion unmanned atop a Delta IV in 2013.  If successful, this mission into high Earth orbit would clear the way for a human asteroid mission around 2015.

Each day more exoplanets discovered and displayed in the news so often their findings. It is common to know the discovery of a new exoplanet, so-called Hot Jupiters, but, What is a hot Jupiter-like exoplanet?

Currently there are different techniques for the detection of these bodies around other stars: radial velocity measurement (distance or closer to the star to us) or the proper motion (motion with respect to bottom) of the star for transits (the planet passes between the star and us, causing a drop in the observed brightness in the star) or by direct observation. All these techniques have limitations as to the bodies that can detect, and that as technology improves (especially with the use of space telescopes and adaptive optics) this limit is reduced.[ Translated via Google Translate]

Francisco Sevilla of  Vega0.0 blog Discusses Exoplanetas de tipo Júpiteres Calientes.[Spanish]

Here is English version: Hot Jupiter Type Exoplanets.

Here is article on Dinosaur extinction mystery where Victor Babbitt proposes new theory regarding K-T Extinction.

Extinction in itself is, throughout geologic history, the norm rather than the exception.  The fact that many species perished in the aftermath of the many environmental calamities that occurred around 65 million years ago, (the Chicxulub asteroid impact and Deccan Volcanism) is hardly surprising.  The real question has always been the differential survival of species.  Dinosaurs were the dominant land animals for over 100 million years, the dominant herbivores, the dominant predators, ranging from chicken size to the largest land animals that ever lived, adapted to every environment, and living on every continent from pole to pole.  The question of  how this dominance ended is important, as it is fully possible that without this extinction, dinosaurs would still rule the earth, and mammals might still be rat sized animals rustling through the underbrush.

Cheers up!!

Earth-like Planets are Common in Universe!!

Planet Earth is not so special after all; there’s one orbiting roughly every one in four Sun-like stars, according to a five-year astronomy study. The study, published in the journal Science, used Hawaii’s twin 10-metre Keck telescopes to scan 166 sun-like stars within 80 light years, or about 757 trillion kilometres. The team spotted 22 planets around 33 of these stars by the gravitational tug of the planets – called the Doppler or radial velocity method.

23 Earths for every 100 Suns

Of about 100 typical Sun-like stars, one or two have planets the size of Jupiter, roughly six have a planet the size of Neptune,and about 12 have super-Earths between three and 10 Earth masses. How tough the search for habitable worlds would be wasn’t at all clear when NASA gave the Kepler team the go-ahead almost 10 years ago. Only huge, scorching-hot exoplanets larger than Jupiter had been found by then. Limitations in the technique mean astronomers can’t yet see planets up to three times Jupiter’s mass orbiting within one quarter of the distance of the Earth to the Sun (1 AU or almost 150 million kilometres), or smaller Earth-like planets much close in.

Image: The data, depicted here in this illustrated bar chart, show a clear trend. Small planets outnumber larger ones. Astronomers extrapolated from these data to estimate the frequency of the Earth-size planets — nearly one in four sun-like stars, or 23 percent, are thought to host Earth-size planets orbiting close in. Each bar on this chart represents a different group of planets, divided according to their masses. In each of the three highest-mass groups, with masses comparable to Saturn and Jupiter, the frequency of planets around sun-like stars was found to be 1.6 percent. For intermediate-mass planets, with 10 to 30 times the mass of Earth, or roughly the size of Neptune and Uranus, the frequency is 6.5 percent. And the super-Earths, weighing in at only three to 10 times the mass of Earth, had a frequency of 11.8 percent. NASA/JPL-Caltech/UC Berkeley[via: Centauri Dreams]

One of astronomy’s goals is to find eta-Earth (η-Earth), the fraction of Sun-like stars that have an Earth. This is a first estimate, and the real number could be one in eight instead of one in four. But it’s not one in 100, which is glorious news. What this means is that, as NASA develops new techniques over the next decade to find truly Earth-size planets, it won’t have to look too far. Greenhill’s expertise is in the ‘microlensing technique’, which looks at the bending of light of a source star by an intervening planet-star system and is particularly suitable for finding small-mass planets. He estimates between 32% and 100% of stars have planets two to 10 times the size of Earth in orbits ranging from 1¬-10 AU. That’s one heck of a lot of Earth-mass planets. I don’t care how small the probability of life is; some of them are bound to have water on them and will probably have life there.

Remark: It simply suggests that there could be more and more Earth like planet irrespective to our probablistic estimations. In a previous article , I’ve presented a detailed information about temporal temperature zones and wind maps, which supports my earlier speculation of planet being habitable . In that article you can see that wind flow maps of Gliese 581g are similar to wind map of planet Earth at various locations. All of these calculations and evidences dismay the idea of planet being inhabitable. Now this study presents even more optimistic speculation as to how common Earth like planets are. Rare Earth hypothesis goes to hell.

[Source: Cosmos Magazine]
[Note: In original article they referred 80million light years as ~757 trillion kilometers. There should be instead 80 light years.]

On The Habitability of Gliese 581g: Review

The Gliese 581 system has been making headlines recently for the most newly announced planet that may lie in the habitable zone. Hopes were somewhat dashed when we were reminded that the certainty level of its discovery was only 3 sigma (95%, whereas most astronomical discoveries are at or above the 99% confidence level before major announcements), but the Gliese 581 system may yet have more surprises.

When the second planet, Gliese 581d, was first discovered, it was placed outside of the expected habitable zone. But in 2009, reanalysis of the data refined the orbital parameters and moved the planet in, just to the edge of the habitable zone. Several authors have suggested that, with sufficient greenhouse gases, this may push Gliese 581d into the habitable zone. A new paper to be published in an upcoming issue of Astronomy & Astrophysics simulates a wide range of conditions to explore just what characteristics would be required.

Artist impression of Gliese 581 g, which is thought to have three times the mass of Earth. Credit: Lynette Cook

The team, led by Robin Wordsworth at the University of Paris, varied properties of the planet including surface gravity, albedo, and the composition of potential atmospheres. Additionally, the simulations were also run for a planet in a similar orbit around the sun (Gliese581 is an M dwarf) to understand how the different distribution of energy could effect the atmosphere.

The team discovered that, for atmospheres comprised primarily of CO₂, the redder stars would warm the planet more than a solar type star due to the CO₂ not being able to scatter the redder light as well, thus allowing more to reach the ground.

One of the potential roadblocks to warming the team considered was the formation of clouds. The team first considered CO₂ clouds which would be likely towards the outer edges of the habitable zone and form on Mars. Since clouds tend to be reflective, they would counteract warming effects from incoming starlight and cool the planet. Again, due to the nature of the star, the redder light would mitigate this somewhat allowing more to penetrate a potential cloud deck.

Should some H₂O be present its effects are mixed. While clouds and ice are both very reflective, which would decrease the amount of energy captured by a planet, water also absorbs well in the infrared region. As such, clouds of water vapor can trap heat radiating from the surface back into space, trapping it and resulting in an overall increase. The problem is getting clouds to form in the first place.

Astronomers have discovered many planets orbiting the star Gliese 581. This artist’s representation shows Gliese 581 e (foreground), which is only about twice the mass of our Earth. Other confirmed planets in the system are 16 (planet b, nearest to the star), 5 (planet c, center), and 7 Earth-masses (planet d, with the bluish color). Credit:ESO

The inclusion of nitrogen gas (common in the atmospheres of planets in the solar system) had little effect on the simulations. The primary reason was the lack of absorption of redder light. In general, the inclusion only slightly changed the specific heat of the atmosphere and a broadening of the absorption lines of other gasses, allowing for a very minor ability to trap more heat. Given the team was looking for conservative estimates, they ultimately discounted nitrogen from their final considerations.

With the combination of all these considerations, the team found that even given the most unfavorable conditions of most variables, should the atmospheric pressure be sufficiently high, this would allow for the presence of liquid water on the surface of the planet, a key requirement for what scientists maintain is critical for abiogenesis. The favorable merging of characteristics other than pressure were also able to produce liquid water with pressures as low as 5 bars. The team also notes that other greenhouse gasses, such as methane, were excluded due to their rarity, but should the exist, the ability for liquid water would be improved further.

Ultimately, the simulation was only done as a one dimensional model which essentially considered a thin column of the atmosphere on the day side of the planet. The team suggests that, for a better understanding, three dimensional models would need to be created.

In the future, they plan to use just such modeling which would allow for a better understanding of what was happening elsewhere on the planet. For example, should temperatures fall too quickly on the night side, this could lead to the condensation of the gasses necessary and put the atmosphere in an unstable state.

Additionally, as we discover more transiting exoplanets and determine their atmospheric properties from transmission spectra, astronomers will better be able to constrain what typical atmospheres really look like.

Atmospheric Circulation Simulation and Habitability

Ever since the planet has been discovered, a lot of rumors came to existence like detection of so called and long awaited ‘alien signal’. I tend to agree with preamble that there could indeed be life but human life, not exactly good claim without any compelling evidence. The next frontier in extrasolar planet-hunting is the discovery and characterization of Earth-sized exoplanets — “exo-Earths”. A particularly promising route is to search for such planets around nearby M stars. M dwarf stars have several unique attributes that are driving exoplanet studies and astrobiology, as well as next-generation interferometry and direct imaging missions; they constitute at least 72% of nearby stars. As the least massive stars, they have the greatest reflex motion due to an orbiting exoplanet. Furthermore, the classical habitable (liquid water) zone around M dwarfs is typically located in the range  0.1–0.2 AU, corresponding to orbital periods of  20 to 50 days — well matched to the capabilities of ground based precision-Doppler surveys. With such short periods, hundreds of cycles of a few-Earth-mass planet can be obtained within a decade, realizing factors of at least 10 in increased sensitivity for strictly periodic Keplerian signals and enabling Doppler reflex barycentric signals as small as 1 m s−1to be recovered even in the presence of similar-amplitude stellar jitter and Poisson noise. Although these attributes have only recently become widely recognized by the astronomical community, many of the nearest M stars have been prime targets for scrutiny by leading precision-radial-velocity surveys for over a decade now.

Two bodies with a major difference in mass – a star and a planet -- orbit around a common center of mass, or ‘barycenter’ (defined in this animation by the red cross). Astronomers look at the Doppler shift of light as the star moves back and forth, but additional orbiting planets can create a very complicated signal. Credit: Zhatt

One of the most enticing and proximate exoplanet systemsbeing scrutinized is Gliese 581, with at least four exoplanets orbiting a nearby (6.3 pc) M3V star. Two of the exoplanets announced are apparently“super-Earths” that straddle its habitable zone. Recently, Vogt announced two more exoplanet candidates orbiting this star — one with a minimum mass of 3.1 M(Gliese 581g) and an orbital distance of about 0.15 AU, placing it squarely within the habitable zone of its parent star. It is generally accepted that, for stellar masses below 0.6 M, an Earth-mass exoplanet orbiting anywhere in the habitable zone becomes tidally locked or spin-synchronized within the first Gyr of its origin, such that it keeps one face permanently illuminated with the other in perpetual darkness. Such tidal locking will greatly influence the climate across the exoplanet and figures prominently in any discussion of its potential habitability.

Simulation and Results

Figure below shows the Mollweide projection(Pseudo-cylindrical projection of a globe which conserves area but not angle or shape. Also called the “homalographic projection”) of a snapshot from the simulation where Gliese 581g is assumed to be tidally-locked. Since the rotational period of about 37 days is much longer thanthe radiative cooling time (about 4 days), the structure of the flow is sculpted by radiation rather than advection. The relatively fast cooling time implies that the global temperature map relaxes approximately to the input thermal forcing function.

While such visualizations are aesthetically pleasing, more insight is provided by looking at the temporally-averaged temperature and wind maps as functions of  longitude and latitude — the long-term, quasi-stable climate. This is shown in Figure 2, in which they contrast both the tidally-locked and non-tidally-locked cases. For the tidally-locked case, the permanent day side of the exoplanetis just within the classical T = 0◦–100◦C habitable temperature range. In the case where the rotational period is assumed to beequal to one Earth day, the flow is dominated by advection rather than radiation, with temperatures at the equator hovering around afew degrees Celsius. The pair of global temperature maps in Figure(2) makes the point that conclusions on the exact locations for habitabilityon the surface of an exo-Earth depend upon whether the assumption of tidal locking is made. Even on the cold night side, the temperatures are comparable to those experienced in Antarctica where colonies of algae have been discovered and analyzed. All of these statements are made keeping in mind that temperature is a necessary but insufficient condition for habitability.

Figures 3 and 4 show the global zonal and meridional windmaps, respectively. In the case of a tidally-locked Gliese 581g, large-scale circulation cells transport fluid across hemispheric scales at speeds  1 m/s, comparable to typical wind speedson Earth. These cells have a slight asymmetry from west to east due to the rotation of the exoplanet. If the exoplanet instead has a rotational period of one Earth day, there is longitudinal homogenizationof the winds with a counter-rotating jet at the equator andsuper-rotating jets at mid-latitude. The meridional wind map is nowcharacterized by smaller structures. The slightly faster wind speeds recovered from the simulation with a rotational period of one Earthday are artifacts of assuming a higher value of
temperature difference between equator and poles of the planet — nevertheless, the global structure of the wind maps are robust predictions of the simulations.

To further explore the interplay between radiative cooling andadvection, we execute another simulation where the radiative cooling(originally 4 Earth days) and Rayleigh friction (originally  1Earth day) times are set to be 36.562 times their fiducial values— in essence, we are scaling by the ratio of the rotational periodsof (a tidally-locked) Gliese 581g to Earth. Due to the longer cooling time assumed, we now run the simulation for 3000 Earth days and discard the first 2000 days so as to attain quasi-equilibrium. The Mollweide snapshot of the temperature and velocity fields, as well as the long-term wind maps, are shown in Figures 5. Since advection occurs somewhat faster than radiative cooling,zonal winds on the exoplanetary surface develop a stronge reast-west asymmetry and there are hints of energy transport from the permanent day to the night side. The chevron-shaped feature residing around the substellar point is reminiscent of that seenat  0.1 bar in 3D atmospheric circulation simulations of  hot Jupiters. Trailing the featureare large-scale vortices spanning about a third of the hemisphere insize — their large sizes are a consequence of the Rossby deformationlength scale being relatively larger due to the slower rotationof the exoplanet when tidally locked.[ref]

Generally, these studies make the point that anexoplanet found outside of the classical habitable zone may not beuninhabitable — conversely, an exoplanet found within the zonemay not be inhabitable. It simply depends upon life as how it adapts the conditions. Quoting from my previous article “Gliese 581g: Earthlike Exoplanet may Harbor Potentially Rich Alien Life!!”

The search for extraterrestrial life is encouraged by a comparison between organisms living in severe environmental conditions on Earth and the physical and chemical conditions that exist on some Solar System bodies. The extremophiles that could tolerate more that one factor of harsh conditions are called poly-extremophiles. There are unicellular and even multicellular organisms that are classified as hyperthermophiles (heat lovers), psychrophiles (cold lovers), halophiles (salt lovers), barophiles (living under high pressures), acidophiles (living in media of the lower scale of pH). At the other end of the pH scale they are called alkaliphiles (namely, microbes that live at the higher range of the pH scale). Thermo-acidophilic microbes thrive in elevated thermo-environments with acidic levels that exist ubiquitously in hot acidic springs.Cyanidium caldarium, is a classical example of an acido-thermophilic red alga that thrives in places such as hot-springs (<570 and in the range 0.2-4 pH). This algal group shows a higher growth rate (expressed as number of cells and higher oxygen production when cultured with a stream of pure CO2, rather than when bubbled with a stream of air (Seckbach, 2010). It has been reported that Cyanidium cells resisted being submerged in sulfuric acid (1N H2SO4). This is a practical method for purifying cultures in the laboratory and eliminating other microbial contamination (Allen, 1959). The psychrophiles thrive in cold environments, such as within the territories found in the Siberian permafrost, around the North Pole in Arctic soils, and they may also grow in Antarctica.

Microbes Thriving Below Antarctic Ice

 

 

Recently, the segmented microscopic animals tardigrades, (0.1 – 1.5 mm) have been under investigations (Goldstein and Blaxter, 2002; Horikawa, 2008). These “water bears” are polyextremophilic, and are able to tolerate a temperature range from about 00C up to + 1510C (much more that other known microbial prokaryotic extremophiles, Bertolani et al., 2004). But even low Earth orbit extreme temperatures are possible: tardigrades can survive being heated for a few minutes to 151°C, or being chilled for days at -200°C, or for a few minutes at -272°C, 1° warmer than absolute zero (Jönsson et al., 2008). These extraordinary temperatures were discovered by an ESA project of research into the fundamental physiology of the tardigrade, named TARDIS. Tardigrades are also known to resist high radiation, vacuum, and anhydrous condition for a decade in a dehydrated stage and can tolerate a pressure of up to 6,000 atmospheres. These aquatic creatures are ideal candidates for extraterrestrial life and for withstanding long periods in space. They have already been used in space and have survived such stress. That’s why I find it indulging to speculate Why Extraterrestrial Contact is ‘NOT’ Blithering?

Hope there is life!

[Source: Astrobiology Magazine]

[Ref: Gliese 581g as a scaled-up version of Earth: atmospheric circulation simulations by Kevin Heng and Steven S. Vogt]

Small Asteroid Pass Within Earth and Moon

Image via Wikipedia

A small asteroid will fly past Earth early Tuesday within the Earth-moon system. The asteroid, 2010 TD54, will have its closest approach to Earth’s surface at an altitude of about 45,000 kilometers (27,960 miles) at 6:50 EDT a.m. (3:50 a.m. PDT). At that time, the asteroid will be over southeastern Asia in the vicinity of Singapore. During its flyby, Asteroid 2010 TD54 has zero probability of impacting Earth. A telescope of the NASA-sponsored Catalina Sky Survey north of Tucson, Arizona discovered 2010 TD54 on Oct. 9 at (12:55 a.m. PDT) during routine monitoring of the skies.

2010 TD54 is estimated to be about 5 to 10 meters (16 to 33 feet) wide. Due to its small size, the asteroid would require a telescope of moderate size to be viewed. A five-meter-sized near-Earth asteroid from the undiscovered population of about 30 million would be expected to pass daily within a lunar distance, and one might strike Earth’s atmosphere about every 2 years on average. If an asteroid of the size of 2010 TD54 were to enter Earth’s atmosphere, it would be expected to burn up high in the atmosphere and cause no damage to Earth’s surface.

The distance used on the Near Earth Object page is always the calculated distance from the center of Earth. The distance stated for 2010 TD54 is 52,000 kilometers (32,000 miles). To get the distance it will pass from Earth’s surface you need to subtract the distance from the center to the surface (which varies over the planet), or about one Earth radii. That puts the pass distance at about 45,500 kilometers (28,000 miles) above the planet.

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called “Spaceguard,” discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

 

A newly discovered car-sized asteroid will fly past Earth early Tuesday. The asteroid, 2010 TD54, will make its closest approach to Earth at 6:51 EDT a.m. (3:51 a.m. PDT). Image credit: NASA/JPL

 

 

NASA Thruster Test Aids Future Robotic Lander’s Ability to Land Safely

NASA’s Marshall Space Flight Center in Huntsville, Ala., collaborated with NASA’s White Sands Test Facility in Las Cruces, N.M., and Pratt & Whitney Rocketdyne in Canoga Park, Calif., to successfully complete a series of thruster tests at the White Sands test facility. The test will aid in maneuvering and landing the next generation of robotic lunar landers that could be used to explore the moon’s surface and other airless celestial bodies.

The Robotic Lunar Lander Development Project at the Marshall Center performed a series of hot-fire tests on two high thrust-to-weight thrusters – a 100-pound-class for lunar descent and a 5-pound-class for attitude control. The team used a lunar mission profile during the test of the miniaturized thrusters to assess the capability of these thruster technologies for possible use on future NASA spacecraft.

The test program fully accomplished its objectives, including evaluation of combustion stability, engine efficiency, and the ability of the thruster to perform the mission profile and a long-duration, steady-state burn at full power. The test results will allow the Robotic Lander Project to move forward with robotic lander designs using advanced propulsion technology.

The test articles are part of the Divert Attitude Control System, or DACS, developed by the U.S. Missile Defense Agency of the Department of Defense. The control system provides two kinds of propulsion — one for control and the other for maneuvering. The Attitude Control System thrusters provide roll, pitch and yaw control. These small thruster types were chosen to meet the golf-cart-size lander’s requirement for light-weight, compact propulsion components to aid in reducing overall spacecraft mass and mission cost by leveraging an existing government resource.

The Missile Defense Agency heritage thrusters were originally used for short-duration flights and had not been qualified for space missions, so our engineers tested them to assess their capability for long-duration burns and to evaluate their performance and combustion behavior. The thrusters are a first step in reducing propulsion technology risks for a lander mission. The results will be instrumental in developing future plans associated with the lander’s propulsion system design.

 

During tests of the five-pound thruster, the Divert Attitude Control System thruster fired under vacuum conditions to simulate operation in a space environment. The tests mimicked the lander mission profile and operation scenarios. Image Credit: NASA/MSFC

 

 

During tests of the 100-pound thruster, the Divert Attitude Control System thruster fired under vacuum conditions to simulate operation in a space environment. The tests mimicked the lander mission profile and operation scenarios. The test included several trajectory correction maneuvers during the cruise phase; nutation control burns to maintain spacecraft orientation; thruster vector correction during the solid motor braking burn; and a terminal descent burn on approach to the lunar surface.

The objective for the five -pound-class thruster test was similar to the 100-pound thruster test with an additional emphasis on the thruster heating assessment due to the long-duration mission profile and operation with MMH/MON-25 — monomethylhydrazine (MMH) fuel and a nitrogen tetroxide (75 percent)/nitrogen oxide (25 percent) (MON-25) oxidizer.

A standard propellant system for spacecraft is the MMH/MON-3 propellant system — containing 3 percent nitric oxide. An alternate propellant system, MMH/MON-25, contains 25 percent nitric oxide. With its chemical composition, it has a much lower freezing point than MON-3, making it an attractive alternative for spacecraft with its thermal benefits and resulting savings in heater power. Because the MMH/MON-25 propellant system has never been used in space, these tests allowed engineers to benchmark the test against the MMH/MON-3 propellant system.

The lower freezing point could save considerable heater power for the spacecraft and increase thermal margin for the entire propulsion system. These tests showed stable combustion in all scenarios and favorable temperature results.

[Image Credit: NASA]