Single biggest obstacle to Earth bacteria thriving on Mars

[Drakkith]

I understand that bacteria were found on a TV camera that was returned from the Moon by one of the Apollo misions

If true, those bacteria are almost certainly from Earth and simply contaminated the camera prior to or just after the mission.

 

[Comeback City]

If true, those bacteria are almost certainly from Earth and simply contaminated the camera prior to or just after the mission.

Yes, and otherwise this would've been HUGE news and the bacteria would've probably got half a dozen sponsorships and shoe contracts already

 

[Arman777]

Theres a bactery called tardigrada I think it can survive on mars

 

[Drakkith]

Theres a bactery called tardigrada I think it can survive on mars

You mean tardigrade? It's an animal, not a bacteria, and it could probably survive on Mars in a dormant state but it would not be able to live and reproduce.

 

[Arman777]

You mean tardigrade? It's an animal, not a bacteria, and it could probably survive on Mars in a dormant state but it would not be able to live and reproduce.

Yeah,I mean that..Oh sorry I didnt much give attention that its bacteria or animal.I see

 

[Al_]

It is unimaginably difficult. Not only is the outside of the spacecraft and rover covered in microbes, but so is every component, every nook and cranny, every cable, every wheel bearing, everything. And even if you sterilize it completely, as soon as you take it out of the chamber or wherever it is that you sterilized it to get it ready for launch, it gets contaminated all over again!

Why don't they sterilise it in an orbiting chamber?

Thnigs that are too delicate like electronics can be sealed inside plastic blocks, and you just sterilise the outside.

 

[Drakkith]

Why don't they sterilise it in an orbiting chamber?

They'd have to build one and put it in orbit for one thing. Which is costly and provides its own set of challenges. Now everything they'd have done on the ground has to be done remotely in space.

Thnigs that are too delicate like electronics can be sealed inside plastic blocks, and you just sterilise the outside.

Sure, but that may add weight and complications to the design. Both of which are the last things you want when designing a remotely controlled rover that has to be launched into space and then landed on another planet. I'm sure NASA did the best they could given the very tight constraints.

 

[Stormbringer]

water bears (or tardigrades) which are a macroscopic animal could probably survive. there probably is at least occasionally liquid water on Mars. The water bear could do what it needs to do when the water is present before it sublimates or is re-frozen. It can survive both the intense cold and heat of empty space. It can survive hard vacuum. It can survive severe radiation. I don't think it gives much of a darn about Ph or most toxins either. The primary problem would probably be getting it's food to survive to sustain it. Though possibly cannibalism for some species of tardigrade might be a temporary possibility. The problem is that the water bear would eventually starve or else be forced to permanent dormancy. You'd still need an algae or moss or lichen or fungi or other suitable food that was capable of surviving in order to create a closed life cycle/food chain for the 'bear. Otherwise the tough little tardigrade would probably just "shoot the bird" at the martian environmental challenge.

And if Mars is slightly too tough for the water bear to be able to form a closed cycle food web then the liquid water oceans of Europa and similar places would almost certainly not be.

 

[Drakkith]

And if Mars is slightly too tough for the water bear to be able to form a closed cycle food web then the liquid water oceans of Europa and similar places would almost certainly not be.

I disagree. The tardigrade would almost certainly be unable to survive on another world. And by 'survive' I mean live and reproduce in a sustainable population, not just remain dormant. Both Mars and those other worlds have no food and little or no air and there is nothing the tardigrade can do to change this.

 

[BillTre]

Here is a news article from Science magazine ow about how some tough Earth bacteria are killed pretty well by UV such would be found in sunlight on Mars.
However, bacteria could still hide in dark areas.

 

[Torbjorn_L]

The question reminded me of the article that BillTree mentions, that shows how UV light is probably the largest problem on the surface. (Mind that the experiment is limited as of yet using just one hardy strain; though since it was drought resistant it should also be radiation resistant due to the copious DNA repair mechanisms.)The question is hard to answer since it maps a lot of source ecologies of thermophiles onto a lot of potential cornucopia of ecologies on Mars from the top of its atmosphere way down in the crust. The most promising current habitat would be deep in the crust, in which case any living populations would share much the same conditions as deep in our crust. Though Yggdrasil's article may point in other directions...On another matter, though I appreciate curiosity on behalf of science I also appreciate (due) diligence. Here are some curious references that a modicum of googling would have rejected:

Interesting... there were meteorite rocks with bacteria found within these rocks blasted from Mars during a strike from a meteor long ago.See: http://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.shtml

The modern consensus is that it was neither nano-cells (too small to be anything like "bacteria") nor fossil remains of them. Every property found has an abiotic explanation. [ https://en.wikipedia.org/wiki/Allan_Hills_84001 ]

http://www.iflscience.com/space/marine-plankton-found-surface-international-space-station/How could such plankton survive ...

There are - as far as I know - no peer review articles that has shown any such data.

I understand that bacteria were found on a TV camera that was returned from the Moon by one of the Apollo misions

Due to failures of protocol lab contamination after opening the camera cannot be excluded and is the most likely explanation. [ https://en.wikipedia.org/wiki/Reports_of_Streptococcus_mitis_on_the_Moon ]