Earth Microbes May Survive On Mars

Vicissidude writes "New Scientist is reporting that terrestrial microbes who hitch a ride to Mars on spacecraft may be able to survive under special circumstances." From the article: "...Mars's thin atmosphere allows such intense ultraviolet radiation to reach the planet's surface - triple that found on Earth - that any life inadvertently carried on the spacecraft is thought to be wiped out quickly...However, the bacteria were able to stay alive if they were shielded by just 1 millimeter of soil during the tests, which ran for up to 24 hours. Under such a protective coating, the bacteria could survive - and potentially grow - under the high Martian UV flux if water and nutrient requirements for growth were met."

Comments

UV resistant cultures

[dukerobinson]

Bacteria can be grown to be resistant to nearly anything, within reason, given enough generations. It seems that if we wanted to seed Mars with life, we could take a suitable microbe, expose it to martian level radiation until 99% of the organisms are eliminated, then allow it to regrow, then expose to radiation, regrow, and continue this process until the UV is no longer harmful. The nutritional substrate would have to be something similar to that found on the martian surface, of course, but it really does not seem that far fetched to me. the real concern would be, do we want to seed mars with life before we are certain that there is no native microbial life?

Re:UV resistant cultures

[Timesprout]

I love this 'seed mars with life' statement. Putting bacteria up there is not seeding the planet with life, its seeding it with little eating machines with no guarantee they will do anything except consume all the resources they can.

Re:Exploition for Terra-Forming

[Anonymous Coward]

Earth lifeforms can survive on mars*

*when they are protected from the nasty environment there.

Yes, Earth lifeforms can also survive on Earth, when protected from the molten core by a thin layer of dirt and protected from the vaccuum of space by a thin layer of air and protected from solar radiation by a thin layer of air and, for humans, when protected from the oceans by another layer of dirt.

Surprise, surprise, things only survive when not directly exposed to things inimical to them.

Re:Planting life?

[aliquis]

Except what is lost is lost, so the amount of water molecules, oxygen, hydrogen and so on will become less all the time.

Re:Planting life?

[JDevers]

Cockroaches may be hardy compared to most other higher life forms, but compared to many bacteria they have one foot in the grave and the other 5 on a banana peel the moment they hatch. The simple fact that they are eukaryotic means they are very fragile life forms with fairly rigid life requirements. Cockroaches aren't all that much more rad-hardened than us. They have the same potential problems as we do (direct DNA damage) and the same repair mechanisms so most of their "resistance" is as a species, not an individual. They are small, tend to live in places that would shield them somewhat from any sort of radiation, need very small amounts of food and water to live, the food they need can easily come from leftover human trash, and they reproduce prolifically. These things together make them a very hardy species, but without O2 they die quite quickly.

There are MANY bacteria (including some of the best survivors) which need no gases to live. There are bacteria which need nothing but Fe2+ or elemental sulfur, water, and an inorganic carbon source to live. While the vast majority of life that you and I see every day uses the standard aerobic respiration of glucose or photosynthesis to survive, there are definitely a lot of other core catabolic processes at the bacterial level.

Re:We should be doing this *now* deliberately

[Colin Smith]

"Not at least until we know more about mars's previous biosphere and if one currently exists."

Bugger Mars's previous biosphere.

Have you never seen a lion eat a gazelle? How about a chimpanzee tear apart a monkey. Sharks eating seals, starfish eating coral, ladybirds eating aphids.

Life kills and eats other life *all* the time. If you can't survive, your genes aren't good enough to exist. Any existing life on Mars doesn't deserve to live if it can't compete with Earth microbes.

If everyone worried about what future generations might think, nothing would ever happen.

Re:We should be doing this *now* deliberately

[aaqubed]

If you can't survive, your genes aren't good enough to exist.

Unfortunately, that's not true at all. Re-read Origin of Species - it is not the "best" genes that survive, but the ones most specifically adapted for a particular environment.