Category: Extreme Life

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From orbit, Olympus Mons dominates the landscape of the Tharsis region on Mars. At 24 kilometers (15 miles) high, and 550 kilometers (340 miles) in diameter, the huge volcano is over three times larger than Mount Everest. But Olympus Mons has a structure that is somewhat lopsided: it is elongated to the northwest, shortened to the southeast. A new study reveals that the ‘lopsidedness’ may mean warm magma and possibly water could be close enough to Olympus Mons’ surface to support thermophilic (heat-loving) bacteria like those found near hydrothermal vents on Earth.

While no volcanic activity has ever been seen or detected in Olympus Mons by orbiting spacecraft, the surface of the northwestern scarp has been dated from 115 million years old down to a region that is only 2 million years old. This is very recent in geological terms, suggesting that the mountain may yet have some ongoing volcanic activity.

To try and understand why Olympus Mons in lopsided, researchers Patrick J. McGovern and Julia K. Morgan from the Lunar and Planetary Institute, Universities Space Research Association, constructed detailed computer simulations of the volcano. They found the only way it could have the shape it does is if, when it was actively erupting, lava piled on top of layers of weak, water-laden clay sediments.

These layers could be hiding a trapped reservoir of water, if indeed Mars was once warmer and wetter. Whether that reservoir could still be warm, and if it could possibly hold life life remains uncertain. As of now, no orbiting satellites have any instruments that can penetrate the surface to look for a heat source.

This research was published in February 2009 in the journal Geology.

Source: The Geological Society of America

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It’s been a busy few days for the Phoenix Mars lander rumour-mill. On Friday, an article was published in Aviation Week reporting an undisclosed source from the NASA team analysing results from the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) had come forward saying Phoenix scientists were in communication with the White House. Apparently there had been new, “provocative” results to come from the MECA, possibly a bigger discovery than last Thursday’s announcement about the scientific proof of water in the Martian regolith. Naturally, the blogosphere went crazy in response to this news. Yesterday, the Phoenix team issued a press release focussing on conflicting results from the MECA and Thermal and Evolved-Gas Analyzer (TEGA) instruments. A MECA sample was found to contain a toxic substance known as perchlorate, usually an oxidizing by-product from industrial processes here on Earth. However, a recently analysed sample from the TEGA turned up no supporting evidence for perchlorate. The study is ongoing. Today, the Phoenix team organized a press conference to discuss a more positive view on the possible discovery of perchlorate, and fired back at recent allegations that science was being withheld from the public…

The Phoenix mission has had an outstanding record of transparency and communicating its science into the public domain. So, one can understand the frustration mission scientists felt when “outrageous” stories (according to Peter Smith, Phoenix principal investigator) were circulated by Aviation Week alleging secrecy about Phoenix findings, strongly indicating that something huge had been discovered and the White House had to be notified. “We want to set the record straight…we’re not with-holding anything” NASA spokesman Dwayne Brown declared at the special press briefing today. The Phoenix team went on to say that the sketchy details in the Aviation Week article led to the huge amount of “speculation” that was thrown around in follow-up stories.

Indeed, there was a significant finding in the works, but the scientists needed more time to analyse the results before issuing a press release on finding perchlorate in the MECA sample. Although the Aviation Week article did specifically say Phoenix was not capable of discovering life, it didn’t stop a number of reports indicating that life had been discovered on the Red Planet (hence the need to communicate the discovery with the President’s Science Advisor first). These speculative claims reached fever-pitch, prompting Phoenix’s Twitter feed to state “Heard about the recent news reports implying I may have found Martian life. Those reports are incorrect.” The speed at which these rumours spread was startling and probably took NASA completely off-guard. This is probably why the perchlorate discovery was announced before a complete and rigorous study could be carried out.

So is perchlorate the death-nail for the possibility of finding suitable conditions for life to be seeded? According to Phoenix scientists, oxidizing chemicals are not always ‘bad news’ for life. “It does not preclude life on Mars. In fact it is a potential energy source,” said William Boynton of the University of Arizona. Indeed, perchlorates have been found in Chile’s highly arid Atacama Desert, a location often used as an analogue for the Martian landscape. Organics in nitrate deposits associated with perchlorates have been found in these harsh conditions, possibly indicating life may form in similar circumstances on Mars.

Although the Phoenix scientists are fairly upbeat about this new finding, other scientists not associated with the mission are cautious. At first glance, perchlorate “is a reactive compound. It’s not usually considered an ingredient for life,” said Brown University geologist John Mustard. Regardless, we will have to wait until all the results are in, especially from the follow-up TEGA sample. Jumping to conclusions are obviously not very helpful to the Phoenix team currently trying to decipher what they are seeing from experiments being carried out by a robot, 400 million miles away.

Sources: Space.com, Phoenix, Space News Examiner

We all know how hard life can be, but spare a thought for the microbes recently discovered 1.6 kilometres (1 mile) below the seabed off the coast of Canada. The living conditions are cramped, the environment is a searing 100°C (212F), and yet these hardy cells appear to be thriving. In the midst of the historic landing of Phoenix in the arctic wastes of Mars yesterday, the interest in finding life on the Red Planet has, yet again, reached fever pitch. Although Phoenix isn’t built to look for life, it is assessing the Martian surface water content for signs that it may (or may have been able to) support life. This new discovery of life so deep below the Earth’s surface may set some new limits on just how extreme life can be on other planets…

Off the Newfoundland coastline, scientists have burrowed far below the seabed. Smashing the previous record for subterranean life, this new discovery has found one of the most basic forms of terrestrial life living a mile deep (the previous record held at 842 meters, or 0.5 miles). As I’m no biologist, I’ll leave it to the Reuters news source to describe as to what was found:

Prokaryotes are microbes lacking nuclei, comprising archaea and some types of bacteria. The lack of cell nuclei distinguishes them from eukayrotes, or all animal and plant life. – Reuters

These prokaryote specimens were scooped from sediments dating 111 million years old. At these depths, the sediment is subjected to temperatures from 60-100°C (140-212F), and John Parks, professor at the University of Wales (UK), belives that this type of microbe can live even deeper. He believes more prokaryotes could be discovered up to 4 km (2.5 miles) below the seabed. This leads to the question as to whether life on other planets may not be found on the surface, but deep inside their crust.

“If there is a substantial subsurface biosphere on earth there could also be substantial biospheres on other planets. Just taking a scoop from the surface of Mars is not going to tell you whether there is life on Mars or not.” – Prof. John Parks

This obviously relates to the attempts made by previous Mars landers to analyse the surface for extraterrestrial microbes. However, a lot of information can be gained by analysing the surface composition for the materials required by life (as we know it) to survive. The Phoenix lander for instance was not designed for life hunting in mind, but it was designed to analyse the top layer of regolith for water content and evidence that liquid water may have once flowed in recent Mars history. Now we have extended our limit on where life may thrive, missions to Mars will need to burrow deeper into the surface, or we’ll simply have to wait till we can do it ourselves.

It is not clear where these subterranean microbes get their energy from. Sunlight probably isn’t a factor; methane and heat from volcanic vents seem more obvious candidates.

There is a problem associated with finding life this deep. It complicates possible plans to bury carbon dioxide emissions deep underground to slow the effects of climate change. It is a completely untouched ecosystem, dumping our waste could have serious consequences for these colonies of microbes. However, it might take some convincing as the U.N. Climate Panel has announced that carbon dioxide burial may be the key tool in the future to prevent this greenhouse gas from escaping into the atmosphere.

Source: Reuters