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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."
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?
..when the Apollo 12 crew brought back a camera from Surveyor 3. Some microorganisms survived a few years on the moon. See a nasa page for details.
The problem is holding on to that atmosphere. Mars has weak gravity and a weak magnetic field. That allows light atoms and molecules to escape into space, and it's aggravated by the solar wind.
Mea navis aericumbens anguillis abundat
I assume that "triple the UV that reaches Earth" is a mistake, as that would make it close to Australia -- and somehow, judging from pesky Aussies blabbing around on /., there is no massive dying there -- but, selecting species that can survive the radiation is not that hard. We have bacteria that can survive both at temperatures of nearly +100 degrees and -60, we have bacteria that don't need oxygen, we have those who can live in a chloric atmosphere. We wouldn't even have to do any direct genetic manipulation other than simply selection.
This goes for surviving the UV. Getting water is something we are already able to do -- even if we don't have it in ready form, oxygen and hydrogen come in plentiful supplies. And for the nutrients, just take some protists with you. Heck, they most likely will be able to use the UV for photosynthesis.
Terraforming Mars is more a matter of a huge engineering project, as the technology we need is already discovered.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
Remember in H.G. Wells's The War of the Worlds how our germs were Earth's last best defense against the invading Martians? Good to know we're developing a first-strike capability...
Seeing bad movies only encourages them. Watch responsibly
Not just spacecraft: Earth microbes can hitch a ride to Mars on meteorites, too.
Just as meteorites from Mars are found on Earth (eg. in Antarctica), meteorites from Earth may reach Mars, and these meteorites may carry microbes. Some scientists think there's an exchange of biological material between the two planets.
The Mars rover Opportunity recently found an iron meteorite on Mars.
Earth Microbes placed on Mars appear to be stuck in a sand dune.
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Right, this means that in a period of million years the atmosphere we put on Mars will be mostly gone.
And the terraforming we're talking about will take what, 100-1000 years? When the atmosphere escapes into space, we can simply repeat the process (assuming no maintenance on the way).
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
Except what is lost is lost, so the amount of water molecules, oxygen, hydrogen and so on will become less all the time.
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.
"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.
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When the 1976 Viking experiments detected possible signs of life, one of the suspects was bacteria from Earth. Since it was believed that life wouldn't surive the trip to Mars, the validity of this hypothesis compared to the idea that the bacteria is Martian (or the idea that it was a false positive due to nonliving sources) has been the debate of scientists for a while. We'll have to wait until someone recovers the Viking probes to know the true source of that possible signature.
According to my astronomy teacher, when the Sun started fusing hydrogen, it blew out the light and volatile material from the inner solar system. That's why the inner planets are mostly rock and iron. When you get to Jupiter and beyond, the planets captured most of the light and volatile material. Titan's surface temperature is very low, so that helps reduce the rate at which it loses its atmosphere. Its atmosphere is mostly molecular nitrogen, which is a relatively heavy molecule. It may have already lost almost all of the hydrogen and helium that was in its early atmosphere.
Mea navis aericumbens anguillis abundat