Friday, September 28, 2007

Microbes on Mars (lets hope they aren’t too virulent)

Martians are generally imagined as three fingered, green, bald headed creatures; however, recent theory suggests that the Martians may be or have been microorganisms.

It is believed that Mars may have once had water on its surface. As we all know, on Earth, water means life. Channels and craters on Mars differ from those on the Moon or Mercury, which make scientists believe that water may be present on Mars. As it turns out, Mars has massive polar ice caps (complete with a permafrost layer) which, if melted, would produce enough water to cover the entire planet “eleven meters” deep.

Water, as a liquid however, cannot exist except at very low elevations because of the weak atmosphere. Still, it is thought because of the unusual craters and striations across the planet that beneath the ice lays even more water. In 2002, the Mars Odyssey spacecraft used its gamma ray spectrometer and confirmed that there is “enormous quantities of water ice beneath the surface of Mars.”

It is further argued that there must have been -or still is- water on Mars due to its “debris pattern and colouring” though this is possibly due to carbon dioxide frost or dust movement. However, many believe that the presence of hematite and goethite (“usually formed in a wet environment”) found on Mar’s surface is indicative of water’s presence and lends hope to there having been life on Mars. To further that hope, in December of 2006, scientists believed that the geological changes shown in photographs at the time suggest that water occasionally flows over parts of the surface.

In addition to water possibly being on its surface, Mars boasts a small atmosphere with methane gas pockets throughout. Due to the methane pockets and polar ice caps, the most recent theory is that if microbes existed on Mars they would be much like our terrestrial methanogens. Methanogens can live deep in ice (such as in Antarctica or Greenland). If this is true, Mars may already be supporting life. If not, microbes are known for their adaptability and tenacity; it is possible that they are dormant.

Many of the experiments done on Mars (1970’s) to see if microbial life existed there were done with saline as the main “internal fluid” in mind. It is now thought that these series of tests would have only drowned or burned the possible life forms. With the cold and dry (water is not really observable) climate it is thought that, should the microorganisms exist, they would be made up of water and hydrogen peroxide as it freezes at a much lower temperature.

Among the previous theories lies another: the possibility that microbes on Mars have magnetisomes. A meteorite, named ALH84001, is believed to contain the fossilized remains of microbes from Mars.

However, until it is proven without a doubt that Mars has water, it is impossible to tell whether alien microbes have lived on our neighbouring planet.

References:
http://www.jpl.nasa.gov/releases/2004/88.cfm

http://airandspace.si.edu/etp/Mars/surface/water.html

http://en.wikipedia.org/wiki/Mars

http://www.pnas.org/cgi/reprint/98/24/13490?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=%28Mars+AND+magnetite%29&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

http://www.pnas.org/cgi/reprint/98/5/2164?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=%28Mars+AND+magnetite%29&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

http://abcnews.go.com/Technology/WireStory?id=2776816&page=1


6 comments:

Dominic B. said...

Recently, John Severson, professor of biology at St. Louis University said this:

-"On Earth we see life in extreme environments such as Antarctic ice and black smoker chimneys at the bottom of the ocean that are scalding[...]If we see organisms on Earth surviving in extreme environments like these, the possibility exists they may do so elsewhere."

I totally agree with this. The problem is to find proof of this life...without easy access to another planet one can only speculate. With regards to the ALH84001 meteorite, many scientists are skeptical about the origin of the "microfossils"...but again...remember how the so called "theory" of spontaneous generation was robust...defying time until Pasteur came around.

cherryblogger71_is said...

I believe this is one of the pictures from ALHG4001: http://nssdc.gsfc.nasa.gov/planetary/thumbnail/marsfossil.jpg

The unusual structures are ~100x smaller than those of most bacteria on Earth.

But you're right, the debate whether Mars has had microscopic life on it is and has been under debate for about a decade now. They sent out samples of ALH84001 to thousands of researchers and still we can decide yes or no.

I was browsing about again and found this site. They're quite informative and I wish I'd found it before I posted. It's definitely worth a read.
http://www.chron.com/disp/story.mpl/space/4096212.html

cherryblogger71_is said...

typo*** They send out samples and still we can't decide yes or no.

Dominic B. said...

I added a picture and title...and also TAGS or labels...this helps people find articles

A said...
This comment has been removed by the author.
cherryblogger71_is said...

Thanks:)