And no, not in "Life on Mars" in the distant past that we think a meteorite might be evidence of, but actual honest to God life currently living on Mars? Well a new report points to a more & more likely "maybe."
Over the past decade, researchers seem to have detected large quantities of methane (CH4, a byproduct of life on Earth) being produced on Mars using spectroscopy. NASA's Infrared Telescope Facility & the W. M. Keck Observatory were used to look at Mars over an extended period of time, and the light was split into its individual wavelengths, allowing the "fingerprint" of individual molecules to be identified.
Given the particulars of the Martian atmosphere, methane is destroyed quickly. So the methane is being actively replenished (19,000 metric tons of the stuff detected in one plume) by something. Ideas for what that something could be have ranged from meteorite impacts, geological reactions, or possibly some form of Martian life is farting methane.
So far, in the past few months, we've discovered water on the Moon, Europa (Jupiter's moon that the Monolith builders told us to stay away from) might be able to support complex life, and now some more info about Mars. According to Scientific American, a UK team of scientists are publishing results of a study that seems to rule out meteorite impacts as a cause for the methane.
Ruling out that theory boosts NASA's suggestion that the methane gas is being given off by living organisms.
The UK experiments were carried out by a team at London's Imperial College. Their results are published tomorrow in the journal Earth and Planetary Science Letters... Co-author of the new study, Dr Richard Court, said: "Meteorites vaporizing in the atmosphere are a proposed methane source but when we recreate their fiery entry in the laboratory we get only small amounts of the gas. For Mars, meteorites fail the methane test."
So that leaves the geological explanation (volcanic rock reacting with water), or a by-product of a lifeform's metabolism as the possible explanations. However.....
The UK team says that previous studies have ruled out volcanism as a cause.
Professor Colin Pillinger, of the Open University, who was behind Britain's ill-fated Beagle 2 mission to Mars in 2003, says he does not accept a volcanic explanation. He points out that the plumes of methane announced by NASA in January are not being produced in areas where there are volcanoes. He told Skymania News: "Methane is a product of biology. For methane to be in Mars' atmosphere, there has to be a replenishable source. "The most obvious source of methane is organisms. So if you find methane in an atmosphere, you can suspect there is life."
Now scientists are keenly awaiting a joint NASA/European probe to Mars in 2018 to dig for direct contact with any mini-Martians. The Imperial team have developed instruments to extract organic material from martian rocks. Professor Mark Sephton, of Imperial College, said: "As Sherlock Holmes said, eliminate all other factors and the one that remains must be the truth..."
My bet is the methane is being produced by Martian Cattle, colloquially known as Buggalo.
It could also be microorganisms within the Martian soil.
From NASA:
If microscopic Martian life is producing the methane, it likely resides far below the surface, where it's still warm enough for liquid water to exist. Liquid water, as well as energy sources and a supply of carbon, are necessary for all known forms of life.
"On Earth, microorganisms thrive 2 to 3 kilometers (about 1.2 to 1.9 miles) beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen (H2) and oxygen. The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon," said [Dr. Michael] Mumma.
"Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons," said Mumma.
Of course, the act of discovery through direct contact has implications of its own. NASA goes to great lengths to "scrub" every spacecraft that lands on another celestial body to insure it's clean & in compliance with the planetary protection policies outlined in the Outer Space Treaty of 1967.
Earlier this year, there was a little bit of worry expressed about possible "forward contamination" from the Phobos-Grunt mission (now scheduled to launch in 2011). It's a joint Russian-Chinese mission that will deploy a Mars orbiter, and then land on the Martian moon Phobos. It will take a soil sample from Phobos, and if everything goes according to plan, send the sample back to Earth.
One of the experiments to onboard the craft has been developed by the Planetary Society. It's called "LIFE" (Living Interplanetary Flight Experiment). It involves putting individual samples of Earth's "hardiest" microbes in about 30 small tubes to test how well life might be able to travel through space, with the samples riding along from launch to the return with the soil sample from Phobos. The intended purpose of the "LIFE" experiment is to test the transpermia hypothesis (an idea that planetary impacts, and the resulting ejection of matter off the surface, may work to spread microscopic life throughout the Universe). To put this in layman's science-fiction terms, think 'The Blob' hitching a ride inside a rock so it could land & eat the guy that poked it with a stick.
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However, there are some concerns about the possible implications if Murphy's Law comes into play. What if the worst happens and the Phobos-Grunt craft should have problems (which a fair amount of spacecraft sent in the direction of Mars have experienced; see "Mars Curse"), and crash on Mars or Phobos? There's a possibility of contaminating either body.
If in the event of failure of the spacecraft & impact on either body, and the microbes should survive a) the trip, b) the crash, and c) exposure to the Martian environment, the situation might make it impossible to ever know the true origin of life that may be found by later surveys. Or if life already exists on Mars & responsible for the methane, the introduction of Earth's microbes could devastate & destroy it.
That would be a big violation of the Prime Directive.