Life found on mars ?

[kcs123]

Source: Journal of Astrobiology and Space Science Reviews.

Looks like legit science article, found it on some other news portal, but can't tell is it true or not.
Short summary: they claim, based on photos taken from Oportunity and Curiosity rovers that on some photos could be microbiotic organisms like algae, fungi, lichens or similar.
Those are old photos, but was never mentioned on other sources before.

Hypothesis is that prokaryotes and eukaryotes may have colonized Mars or it could be that was transfered from Earth. There is oposite opinions from various group of scientists on this topic.
Or is it first april joke from scientists.

What do you think, is it legit ?

[Green Baron]

We have shortly discussed that.

It is a review of existing data and simulations. Some people think they have seen what might eventually look like fungi, or cyanobacteria and wrote that down.

Critique: Morphology alone is not a valid criterion for the analysis of life as it carries too many expectations from the observer. The "stromatolites" are not even remotely similar to their earthly analogies, and ALH84001 does not contain biological residues. So, in principle this is guessing from blurry pictures with the backup of simulations. Iow, these guys saw want they wanted to see.

Sorry, but no sorry. That is not a valid evidence of life, though nobody can exclude life atm, neither in the far martian past nor today, though the former is more probable than the latter.  At least they admit that it is not proof of life, but support for the hypothesis that there may be life. I say there is little support for life on Mars until now, as long as we can't exclude sedimentary, mineralogical or meteorological processes, and in these cases i would certainly assume those above life.

Patience we must have. Hopefully maybe 3 or 4 more years :-)

Edited April 4, 2019 by Green Baron

[kcs123]

8 minutes ago, Green Baron said:

We have shortly discussed that.

I have tried to search for thread about it, but could not found one, so I started this one. Maybe moderators can merge threads ?
I don't visit this subforum often enough.

[Green Baron]

Nope, everything is fine ! I didn't hit the right tone, apparently, sorry for that !

It wasn't meant as a hint, just an intro for my blabla. Will look where that was.

Sorry again !

 

Edit: it was here, page 118 of the pinned thread:

 

Edited April 4, 2019 by Green Baron

[Starstruck69]

Many years ago i did a lot of work with lichens to use as a matrix  indicator for air quality.

I am not sure on the exact composition of mars's atmosphere but they do need oxygen amongst other gases to survive(especially Nitrogen for organic acids /proteins etc). Absence of oxygen i think pretty much leads to absence of lichens but cannot 100% reference this.

I think the article is inconclusive for reasons previously discussed by Green Baron. Not sure of its legitimacy either.

I would not however be surprised if life was found in some form or another especially at the poles maybe a microclimate of some sort.

[kcs123]

18 hours ago, Green Baron said:

Nope, everything is fine ! I didn't hit the right tone, apparently, sorry for that !

It wasn't meant as a hint, just an intro for my blabla. Will look where that was.

Sorry again !

No need for apology, no offense taken. Thanks for sharing thoughs on topic.

At least it is confirmed that is not first april joke . Although, it is still speculation. Scientifically explained speculation that may have some merit, but still speculation.
Found two more articles about topic, one that explain that is possible that rovers are contaminated with organic materials on earth. And other one that gives gheological explanation of methane concentration fluctuation trough Mars seasons.

Also, readed somwhere recently about experiment on ISS, where some extremophile life forms placed outside on ISS hull and that those have survived exreme temperature changes, UV radiation and lack of atmosphere for long time period. Can't find source for that info right now, though.

Either way, it seems that currently there is not enough strong evidence to either, confirm or deny hypothesis from OP.

[Green Baron]

On 4/5/2019 at 3:59 PM, kcs123 said:

Also, readed somwhere recently about experiment on ISS, where some extremophile life forms placed outside on ISS hull and that those have survived exreme temperature changes, UV radiation and lack of atmosphere for long time period. Can't find source for that info right now, though.

I assume you refer to an experiment in which tardigrades were exposed to conditions in LEO (hours/days, on the ISS) and partly survived ? These are, afaik the only multicellular organisms so far.

Apart from that, several microorganisms (bacteria) have been exposed directly or to simulated LEO conditions and some have been reported to survive.

Edited April 7, 2019 by Green Baron

[kcs123]

1 hour ago, Green Baron said:

I assume you refer to an experiment in which tardigrades were exposed to conditions in LEO (hours/days, on the ISS) and partly survived ? These are, afaik the only multicellular organisms so far.

Apart from that, several microorganisms (bacteria) have been exposed directly or to simulated LEO conditions and some have been reported to survive.

Could be. It was several weeks ago when I have readed in some article, mentioned it, bu wasn't exactly payed attention to it. IIRC, there was link in that article that I readed to original article about experiment. But can no longer find either of sources. I would probably come across on it when I stop searching it actively .