Slashdot Mirror
Methane on Mars?
mbone writes "Two independent groups are claiming the detection of methane in the Martian atmosphere, one using the
Mars Express orbiter,
and the other using ground based telescopes. This detection, if confirmed, would be of great significance for the search of life on Mars, as Methane will not last long in the Martian atmosphere and thus must be renewed, presumably either by biological processes or by volcanic vents, which would be a good place for life to develop. The leader of the ground based astronomy team, Michael Mumma of the Goddard Space Flight Center, when asked if the methane was biological in origin, said 'I think it is, myself personally.'"
From Research Nebraska
Methane is the second-most abundant greenhouse gas. The world's agricultural livestock produce about 17 percent of the methane in the atmosphere. A byproduct of digestion, cattle and other ruminant animals produce methane when organisms in their stomachs called methanogens break down fiber in grasses and grains they eat.
Here are some pictures of the little critters, and here
This article states that Methane on Earth would have a life of 300 years and that on Mars it'd be shorter.
i ca l/story.jsp?story=505454
http://news.independent.co.uk/world/science_med
"Methane is destroyed by the intense ultraviolet radiation on Mars because the gas has a relatively short photochemical lifetime of about 300 years, so if it is present there must be something producing it continually, Professor Formisano said. "[Its presence] is significant and very important. If it is present you need a source," he added."
Methane is actually odorless. What you smell are mercaptans, which are either biologically generated along with methane, or, in the case of commercial gas, deliberately added to make leaks noticable.
Exponential growth is a best-case situation. In a harsh environment, bacteria replicate very slowly.
It isn't the same, but studies of bacteria living far underground offer a good example. They are starved, tiny. Often less than a thousandth the size of a normal bacteria. Their metabolism is so slow that according to Sci Am they may have an average frequency of cell division of once a *century* or even less.
Mars is even less hospitable. Far colder, far less water, and hardly more nutrients.
It seems to me that if you're going to believe we managed that with the probes it also seems just as likely one could argue for earth bacteria having made it there long ago on meteors.
-- perl -e'print pack"H*","6e656d6f406d38792e6f7267"'
With that said, this certainly is exciting news.
If there turns out to be life on Mars, the best way to go about proving that this life was not carried from Earth by space probes would be very easy.
All one would have to do is study the DNA structure of the Martian life. There would be stark differences between Martian life DNA and Earth life DNA. The best analogy of this I can put forward would be one dealing with snowflakes. On the base level snowflakes are exactly the same thing. They form the same way, and are made of the exact same stuff (ice), but the key difference here is that while there are many similarities, no two snowflakes are exactly the same.
While the base similarities would be the same, there would be sufficient differences in Martian microbe DNA to say with absolute resolve that "These are not Earth bacteria!"