Posted on by Paul Scott Anderson

Should We Terraform Mars?

Artist's conception of a terraformed Mars. Credit: Ittiz/Wikimedia Commons

As we continue to explore farther out into our solar system and beyond, the question of habitation or colonization inevitably comes up. Manned bases on the Moon or Mars for example, have long been a dream of many. There is a natural desire to explore as far as we can go, and also to extend humanity’s presence on a permanent or at least semi-permanent basis. In order to do this, however, it is necessary to adapt to different extreme environments. On the Moon for example, a colony must be self-sustaining and protect its inhabitants from the airless, harsh environment outside.

Mars, though, is different. While future bases could adapt to the Martian environment as well, there is also the possibility of modifying the surrounding environment instead of just co-existing with it. This is the process of terraforming – essentially trying to tinker with Mars’ atmosphere and environment to make it more Earth-like. Although still a long ways off technologically, terraforming the Red Planet is seen as a future possibility. Perhaps the bigger question is, should we?

One of the main issues is whether Mars has any indigenous life or not – how does this affect the question of colonization or terraforming?

If Mars does have any kind of biosphere, it should be preserved as much as possible. We still don’t know yet if any such biosphere exists, but the possibility, which has only increased based on recent discoveries, must be taken into account. Such a precious discovery, which could teach us immensely about how life arose on both worlds, should be completely off-limits. Small colonies might be fine, but living on Mars should not be at the expense of any native habitats, if they exist. The most likely place to find life on Mars is underground. If the surface is truly as sterile and barren as it seems to be, then colonies there shouldn’t be too much of a problem. It has also been suggested that Martian caves would make ideal human habitats, serving as natural protection from the harsh conditions on the surface. True, but if it turned out that something else was already taking up residence in them, then we should leave them alone. If Mars is home to  any indigenous life, then terraforming should be a non-issue.

What if Mars is lifeless? Even if no life otherwise exists there, that pristine and unique alien environment, so far barely scratched by humans, needs to be preserved as is as much as possible. We’ve already done too much damage here on our own planet. By studying Mars and other planets and moons in their current natural state, we can learn so much about their history and also learn more about our own world in that context. We should appreciate the differences in and variety of worlds instead of just transforming them to suit our own ambitions.

There is also the more current but related problem of contamination. There has been a long-standing protocol, via the 1967 Outer Space Treaty, to have all spacecraft going to the Moon or Mars sterilized as much as possible. If bacteria from Earth made it to the Martian surface and survived, it would complicate the search for life there; if a lander or rover was to later identify living organisms in the soil, it might be difficult to determine whether they were just contamination or true native life forms. From both a scientific and ethical perspective, it would seem prudent to try to protect Mars as much as we can from earthly intruders. This applies equally to whether Mars is already inhabited or not. Fortunately, for almost any kind of bacteria or other microrganisms from Earth, it would be very difficult if not impossible to survive on the Martian surface, nevermind flourish. The risk of planet-wide contamination is very negligible, but it is still better to take strict preventive measures than to play with chance.

See also this excellent paper by astrobiologist Chris McKay. Some different views from this article on whether Mars should be protected and preserved at all costs or altered to help life to flourish there, but is a good presentation of the current ideas being put on the table. From the summary:

“Planetary ecosynthesis on Mars is being seriously discussed within the field of planetary science. It appears that restoring a thick atmosphere on Mars and the recreation of an environment habitable to many forms of life is possible. It is important now to consider if it “should” be done. To do this takes us into new and interesting territory in environmental ethics but both utilitarian and intrinsic worth arguments support the notion of planetary ecosynthesis. Strict preservationism arguments do not. It is important to have the long-term view of life on Mars and the possibilities of planetary ecosynthesis. This affects how we explore Mars now. Mars may well be our first step out into the biological universe, it is a step we should take carefully.”

Posted on by Paul Scott Anderson

ASU Researchers Propose Looking for Ancient Alien Artifacts on the Moon

The "Blair Cuspids" spires photographed by Lunar Orbiter 2 in 1966. Credit: NASA

[/caption]

Two researchers at Arizona State University (ASU) have made a rather controversial proposal: have the public and other researchers study the high-resolution photographs of the Moon already being taken by the Lunar Reconnaissance Orbiter (LRO), to look for anomalies that may possibly be evidence of artifacts leftover from previous alien visitation. The theory is that if our solar system had been visited in the past, the Moon would have made an ideal base from which to study the Earth. The paper has just been recently published in the journal Acta Astronautica.

Professor Paul Davies and research technician Robert Wagner admit that the chances of success are very small, but argue that the endeavour would be worth the minimal investment required. The photographs are already being taken on a regular basis by LRO. Any interesting finds could be examined by others including imaging professionals. Shape-recognizing software could also be used to help discern any possible artificial artifacts from natural ones.

From the abstract:

The Search for Extraterrestrial Intelligence (SETI) has a low probability of success, but it would have a high impact if successful. Therefore it makes sense to widen the search as much as possible within the confines of the modest budget and limited resources currently available. To date, SETI has been dominated by the paradigm of seeking deliberately beamed radio messages.

However, indirect evidence for extraterrestrial intelligence could come from any incontrovertible signatures of non-human technology. Existing searchable databases from astronomy, biology, earth and planetary sciences all offer low-cost opportunities to seek a footprint of extraterrestrial technology. In this paper we take as a case study one particular new and rapidly-expanding database: the photographic mapping of the Moon’s surface by the Lunar Reconnaissance Orbiter (LRO) to 0.5 m resolution. Although there is only a tiny probability that alien technology would have left traces on the moon in the form of an artifact or surface modification of lunar features, this location has the virtue of being close, and of preserving traces for an immense duration.

Systematic scrutiny of the LRO photographic images is being routinely conducted anyway for planetary science purposes, and this program could readily be expanded and outsourced at little extra cost to accommodate SETI goals, after the fashion of the SETI@home and Galaxy Zoo projects.

Of course, it has been said by some that such artifacts have already been found and known about for decades but hidden from the public by NASA, et al. An entire cottage industry has grown around this idea. There are actually a handful of anomalies from various missions that would be interesting to see at much higher resolution via LRO, such as the well-known “Blair Cuspids” photographed by Lunar Orbiter 2 in 1966, although by far most unusual-looking objects are easily explained. It’s the same problem as with Mars; so many anomalies found by amateur observers are the product of pareidolia, lighting effects, image defects or even geology. Separating out any genuine anomalies from all of the noise would be a tedious and time-consuming task. On the other hand, we now have much better cameras in orbit around the Moon (and Mars) and more advanced photographic analysis techniques available.

Yes, the chances of finding anything are very small, maybe even nonexistent in the opinion of some, but if we have the images being taken anyway, and the willingness of some to study them, then why not? If nothing is found, no harm done. It something was found, well that’s another story entirely…

The abstract for the paper is here. (The paper itself costs $31.50 US to download).

Posted on by Paul Scott Anderson

Two More Earth-Sized Planets Discovered by Kepler, Orbiting Former Red Giant Star

Credit: S. Charpinet / Univ. of Toulouse

[/caption]

Amid all of the news last week regarding the discovery by Kepler of two Earth-sized planets orbiting another star, there was another similar find which hadn’t received as much attention. There were two more Earth-sized planets also just discovered by Kepler orbiting a different star. In this case, however, the star is an old and dying one, and has passed its red giant phase where it expands enormously, destroying (or at least barbecuing) any nearby planets in the process before becoming just an exposed core of its former self. The paper was just published in the journal Nature.

The two planets, KOI 55.01 and KOI 55.02, orbit the star KOI 55, a subdwarf B star, which is the leftover core of a red giant star. Both planets have very tight orbits close to the star, so they were probably engulfed during the red giant phase but managed to survive (albeit “deep-fried”). They are estimated to have radii of 0.76 and 0.87 that of Earth, the smallest known exoplanets found so far orbiting an active star.

According to lead author Stephane Charpinet, “Having migrated so close, they probably plunged deep into the star’s envelope during the red giant phase, but survived.”

“As the star puffs up and engulfs the planet, the planet has to plow through the star’s hot atmosphere and that causes friction, sending it spiraling toward the star,” added Elizabeth ‘Betsy’ Green, an associate astronomer at the University of Arizona’s Steward Observatory. “As it’s doing that, it helps strip atmosphere off the star. At the same time, the friction with the star’s envelope also strips the gaseous and liquid layers off the planet, leaving behind only some part of the solid core, scorched but still there.”

The discovery was also unexpected; the star had already been the subject of study using the telescopes at Kitt Peak National Observatory, part of a project to examine pulsating stars. For more accurate measurements however, the team used data from the orbiting Kepler space telescope which is free of interfering atmospheric effects. According to Green, “I had already obtained excellent high-signal to noise spectra of the hot subdwarf B star KOI 55 with our telescopes on Kitt Peak, before Kepler was even launched. Once Kepler was in orbit and began finding all these pulsational modes, my co-authors at the University of Toulouse and the University of Montreal were able to analyze this star immediately using their state-of-the art computer models.”

Two tiny modulations in the pulsations of the star were found, which further analysis indicated could only come from planets passing in front of the star (from our viewpoint) every 5.76 and 8.23 hours.

Our own Sun awaits a similar fate billions of years from now and is expected to swallow Mercury, Venus, Earth and Mars during its expansion phase. “When our sun swells up to become a red giant, it will engulf the Earth,” said Green. “If a tiny planet like the Earth spends 1 billion years in an environment like that, it will just evaporate. Only planets with masses very much larger than the Earth, like Jupiter or Saturn, could possibly survive.” The discovery should help scientists to better understand the destiny of planetary systems including our own.

This finding is important in that it not only confirms that Earth-size planets are out there, and are probably common, but that they and other planets (of a wide variety so far) are being found orbiting different types of stars, from newly born ones, to middle-age ones and even dying stars (or dead in the case of pulsars). They are a natural product of star formation which of course has implications in the search for life elsewhere.

The abstract of the paper is here, but downloading the full article requires a single-article payment of $32.00 US or a subscription to Nature.

Posted on by Paul Scott Anderson

Have Complex Molecules Been Found on Pluto’s Surface?

Artist's conception of New Horizons during its flyby of Pluto in 2015. Credit:Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

[/caption]

First there was the recent story about evidence for a possible subsurface ocean on Pluto, of all places. Now there is a new report regarding evidence for complex molecules on its surface, from scientists at Southwest Research Institute and Nebraska Wesleyan University. Little enigmatic Pluto is starting to get even more interesting…

The findings come from the Hubble Space Telescope, using the new and highly sensitive Cosmic Origins Spectrograph which indicate that there is a strong ultraviolet-wavelength absorber on the surface. This absorbing material is thought to likely be complex hydrocarbons and/or nitriles. The results have been published in the Astronomical Journal.

Pluto’s surface is known to be coated with ices composed of methane, carbon monoxide and nitrogen (it is extremely cold there!). The putative molecules can be produced by sunlight or cosmic rays interacting with those ices.

“This is an exciting finding because complex Plutonian hydrocarbons and other molecules that could be responsible for the ultraviolet spectral features we found with Hubble may, among other things, be responsible for giving Pluto its ruddy color,” said project leader Dr. Alan Stern.

The team also found evidence for surface changes in the ultraviolet spectrum, comparing current observations to those from the 1990s. The cause may be an increase in the pressure of Pluto’s tenuous atmosphere or different terrain which is being viewed at different times.

In a unique first for Universe Today, Dr. Alan Stern was the first researcher to be asked questions from readers via the comments section of this recent interview article by Ray Sanders. His answers to the top five questions (as ranked by “likes” on the discussion posts) will be posted soon in a subsequent article. Stern is also the principal investigator for the New Horizons spacecraft currently en route to Pluto.

A copy of the paper by Stern et al. is available here.

With all of the new discoveries already being made about Pluto, it should be very interesting when New Horizons gets there in 2015, providing us with the first close-up look of this fascinating little world.

Posted on by Paul Scott Anderson

Is Jupiter’s Core Liquifying?

Credit: NASA/ESA/E. Karkoschka (U. Arizona)

[/caption]

Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may in fact be self-destructing, gradually liquifying and dissolving over time. This implies it was previously larger than it is now, and may dissolve altogether at some point in the future. Will Jupiter eventually destroy itself completely? No, probably not, but it may lose its heart…

The core is composed of iron, rock and ice and weighs about ten times as much as Earth. That’s still small though, compared to the overall mass of Jupiter itself, which weighs as much as 318 Earths! The core is buried deep within the thick atmosphere of hydrogen and helium. Conditions there are brutal, with a temperature of about 16,000 kelvin – hotter than the surface of the Sun – and a pressure about 40 million times greater than the atmospheric pressure on Earth. The core is surrounded by a fluid of metallic hydrogen which results from the intense pressure deep down in the atmosphere. The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and Saturn, Uranus and Neptune) are called gas giants.

One of the primary ingredients in the rock of the core is magnesium oxide (MgO). Planetary scientists wanted to see what would happen when it is subjected to the conditions found at the core; they found that it had a high solubility and started to dissolve. So if it is in a state of dissolution, then it was probably larger in the past than it is now and scientists would like to understand the process. According to David Stevenson of the California Institute of Technology, “If we can do that, then we can make a very useful statement about what Jupiter was like at genesis. Did it have a substantial core at that time? If so, was it 10 Earth masses, 15, 5?”

The findings also mean that some exoplanets which are even larger and more massive than Jupiter, and thus likely even hotter at their cores, may no longer have any cores left at all. They would be indeed be gas giants in the most literal sense.

The conditions inside Jupiter’s core can’t be duplicated in labs yet, but the spacecraft Juno should provide much more data when it arrives at and starts orbiting Jupiter in 2016.

Posted on by Paul Scott Anderson

New Study Says Large Regions of Mars Could Sustain Life

The Planet Mars. Image credit: NASA
The Planet Mars. Image credit: NASA

[/caption]

The question of whether present-day Mars could be habitable, and to what extent, has been the focus of long-running and intense debates. The surface, comparable to the dry valleys of Antarctica and the Atacama desert on Earth, is harsh, with well-below freezing temperatures most of the time (at an average of minus 63 degrees Celsius or minus 81 Fahrenheit), extreme dryness and a very thin atmosphere offering little protection from the Sun’s ultraviolet radiation. Most scientists would agree that the best place that any organisms could hope to survive and flourish would be underground. Now, a new study says that scenario is not only correct, but that large regions of Mars’ subsurface could be even more sustainable for life than previously thought.

Scientists from the Australian National University modeled conditions on Mars on a global scale and found that large regions could be capable of sustaining life – three percent of the planet actually, albeit mostly underground. By comparison, just one percent of Earth’s volume, from the central core to the upper atmosphere, is inhabited by some kind of life. They compared pressure and temperature conditions on Earth to those of Mars to come up with the surprising results.

According to Charley Lineweaver of ANU, “What we tried to do, simply, was take almost all of the information we could and put it together and say ‘is the big picture consistent with there being life on Mars?’ And the simple answer is yes… There are large regions of Mars that are compatible with terrestrial life.”

So it seems that while, as we know, the surface of Mars is quite inhospitable to most forms of life (that we know of) except perhaps for some extremophiles, conditions underground are a different matter. It is already known that there are vast deposits of ice below the surface even near the equator (as well as the polar ice caps of course), so there could be liquid water a bit deeper where it is warmer. Those conditions would be ideal for bacteria or other simple organisms. While that idea has been proposed and discussed before, Lineweaver’s findings support it on a planet-wide basis – previous studies tended to focus on specific locations in a “piecemeal” approach, but these new ones take the entire planet into consideration.

The paper is currently available for free here. Abstract:

We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of *310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the *5km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to *3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life. Key Words: Biosphere—Mars— Limits of life—Extremophiles—Water. Astrobiology 11, xxx–xxx.

Posted on by Paul Scott Anderson

NASA Planning for Possible Landings on Europa

The Jovian Moon Europa, Credit: NASA/Ted Stryk

[/caption]

All these worlds are yours except Europa
Attempt no landing there
Use them together use them in peace 

Despite that famous cryptic warning in the film 2010: The Year We Make Contact, NASA is planning for a possible attempted landing on Jupiter’s moon Europa. This is a mission that many people have been hoping for, since Europa is believed to have a liquid water ocean beneath the icy surface (as well as lakes within the surface crust itself), making it a prime location in the search for life elsewhere in the solar system. Two landers are being proposed which would launch in 2020 and land about six years later.

As stated by Kevin Hand of JPL, “Europa, I think, is the premier place to go for extant life. Europa really does give us this opportunity to look for living life in the ocean that is there today, and has been there for much of the history of the solar system.”

While the landers wouldn’t be able to access the ocean water which is well below the surface, they could analyze the surface composition with a mass spectrometer, seismometers and cameras. The mass spectrometer could detect organics on the surface if there are any. The landers probably wouldn’t last too long though, because of the intense radiation from Jupiter on the unprotected surface (as Europa has only a very slight, tenuous atmosphere). Accessing any of the water from its ocean or lakes would require drilling deep down, something for a more advanced future mission.

Another mission being considered is a Europa orbiter, which could also launch in 2020. In some ways that might be even better, as it could provide a broader detailed study of the moon over a longer time period. Of course if both missions could be done, that would be fantastic, but budgets will probably only allow for one of them. The lander mission is estimated to probably cost about $800 million to $2 billion, while an orbiter would cost about $4.7 billion.

It might be noted that a return mission to Saturn’s moon Enceladus would also be possible, especially since the water from its subsurface ocean or sea (depending on the various working models of its interior and geology) can be sampled directly from its water vapour geysers, no need to drill down. The Cassini spacecraft has already done that more than once, and has found organics of various complexities, but Cassini’s instruments can’t detect life itself.

Either destination would be exciting, as both are thought to be two of the most likely places in the solar system, besides Earth of course, to be inhabitable or even possibly inhabited. Everywhere on Earth where there is water, there is life. That may or may not be true for Europa or Enceladus, but we’ll never know unless we look.

Posted on by Paul Scott Anderson

Third Rock – NASA’s Cool New Internet Radio Station

Credit: Third Rock Radio/NASA

[/caption]

If you love space and love internet radio, as I do, then this is for you. NASA’s new internet music radio station, Third Rock, was just launched yesterday. With a New Rock/Indie/Alternative music format aimed toward younger, techie listeners, it will feature custom-produced content; a collaboration between NASA and RFC Media in Houston, Texas, it will be operated through a Space Act Agreement, at no cost to the government. As NASA explores space, Third Rock also explores new music, bringing the two together in a fun and unique way.

According to David Weaver, associate administrator for the Office of Communications at NASA Headquarters in Washington, “NASA constantly is looking for new and innovative ways to engage the public and inspire the next generation of scientists and engineers. We have led the way in innovative uses of new media and this is another example of how the agency is taking advantage of these important communication tools.”

Pat Fant, RFC Media co-founder and chief operating officer, adds: “Today’s 4G audience craves new music and enjoys finding it. We’ve pulled out the best songs and the deepest tracks from a full spectrum of rock artists across many styles and decades. NASA features and news items are embedded throughout the programming alongside greetings by celebrity artists.”

You can check out and listen to Third Rock here, and it should be available as an iPhone and Android app soon as well. Happy listening!

Posted on by Paul Scott Anderson

The Habitable Exoplanets Catalog is Now Online!

Credit: The Habitable Exoplanets Catalog, Planetary Habitability Laboratory @ UPR Arecibo (phl.upl.edu)

[/caption]

Anyone who has an interest in exoplanets probably knows about the various online catalogs that have become available in recent years, such as The Extrasolar Planets Encyclopaedia for example, providing up-to-date information and statistics on the rapidly growing number of worlds being discovered orbiting other stars. So far, these have been listings of all known exoplanets, both candidates and confirmed. But now there is a new catalog published by the Planetary Habitability Laboratory (a project of the University of Puerto Rico at Arecibo), which focuses exclusively on those planets which have been determined to be potentially habitable. The Habitable Exoplanets Catalog is a database which will serve as a key resource for scientists and educators as well as the general public.

As of right now, there are two confirmed planets and fourteen candidates listed, but those numbers are expected to grow over the coming months and years as more candidates are found and more of those candidates are confirmed. There is even a listing of habitable moons, whose existence have been inferred from the data, although none have been observed yet (finding exoplanets is challenging enough, but exomoons even more so!).

According to Abel Méndez, Director of the PHL and principal investigator, “One important outcome of these rankings is the ability to compare exoplanets from best to worst candidates for life.” He adds: “New observations with ground and orbital observatories will discover thousands of exoplanets in the coming years. We expect that the analyses contained in our catalog will help to identify, organize, and compare the life potential of these discoveries.”

The big question of course is whether any habitable planets are actually inhabited, two different things. To help answer that, it will be necessary to further analyze the atmospheres and surfaces of those planets, looking for any indication of possible biosignatures such as oxygen or methane. Kepler can’t do that directly, but subsequent telescopes such as the Terrestrial Planet Finder (TPF) will be able to, and provide a more accurate assessment of their physical composition, climate, etc.

Not long ago it wasn’t known if there even were any planets orbiting other stars; now we’re finding them by the thousands and soon we’ll be able to distinguish their unique physical characteristics and have a better idea of how many habitable worlds are out there – exciting times.

Posted on by Paul Scott Anderson

Kepler Confirms First Planet in Habitable Zone of Sun-Like Star

This artist's illustration of Kepler 22-b, an Earth-like planet in the habitable zone of a Sun-like star about 640 light years (166 parsecs) away. Credit: NASA/Ames/JPL-Caltech

[/caption]

Scientists from the Kepler mission announced this morning the first confirmed exoplanet orbiting in the habitable zone of a Sun-like star, the region where liquid water could exist on the surface of a rocky planet like Earth. Evidence for others has already been found by Kepler, but this is the first confirmation. The planet, Kepler-22b, is also only about 2.4 times the radius of Earth — the smallest planet found in a habitable zone so far — and orbits its star, Kepler-22, in 290 days. It is about 600 light-years away from Earth, and Kepler-22 is only slightly smaller and cooler than our own Sun. Not only is the planet in the habitable zone, but astronomers have determined its surface temperature averages a comfortable 22 degrees C (72 degrees F). Since the planet’s mass is not yet known, astronomers haven’t determined if it is a rocky or gaseous planet. But this discovery is a major step toward finding Earth-like worlds around other stars. A very exciting discovery, but there’s more…

It was also announced that Kepler has found 1,094 more planetary candidates, increasing the number now to 2,326! That’s an increase of 89% since the last update this past February. Of these, 207 are near Earth size, 680 are super-Earth size, 1,181 are Neptune size, 203 are Jupiter size and 55 are larger than Jupiter. These findings continue the observational trend seen before, where smaller planets are apparently more numerous than larger gas giant planets. The number of Earth size candidates has increased by more than 200 percent and the number of super-Earth size candidates has increased by 140 percent.

According to Natalie Batalha, Kepler deputy science team lead at San Jose State University in San Jose, California, “The tremendous growth in the number of Earth-size candidates tells us that we’re honing in on the planets Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable. The more data we collect, the keener our eye for finding the smallest planets out at longer orbital periods.”

Regarding Kepler-22b, William Borucki, Kepler principal investigator at NASA Ames Research Center at Moffett Field, California stated: “Fortune smiled upon us with the detection of this planet. The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season.”

Comparison of the Kepler-22 system with our own inner solar system. Credit: NASA/Ames/JPL-Caltech

Previously there were 54 planetary candidates in habitable zones, but this was changed to 48, after the Kepler team redefined the definition of what constitutes a habitable zone in order to account for the warming effects of atmospheres which could shift the zone farther out from a star.

The announcements were made at the inaugural Kepler science conference which runs from December 5-9 at Ames Research Center.

See also the press release from the Carnegie Institution for Science here.