Warning – angry rant, lots of swears
So after the weeks of hype build-up NASA released their
latest big findings from the Curiosity Rover last night. Sensationalist
clickbait tweets and headlines from the scientific media seem to tell us that
we’ve finally got direct evidence of life on Mars:
‘Scientists for the first time have confidently identified
on Mars a collection of carbon molecules used and produced by living organisms’
@nytimes
‘Mars has complex organic material that may be from ancient
life’ @newscientist
‘NASA finds ‘building
blocks of life’ in 3 billion-year-old lakebed on Mars….is there finally proof
of alien life on the red planet’ The Sun
And that bastion of
great science reporting The Express goes full on with ‘Life on Mars: NASA finds
‘HOLY GRAIL’ in rover search for ALIEN LIFE’ and ‘Nasa UNCOVERS evidence of LIFE on Mars in
latest SHOCK revelations’- actually fucking capitalising the bollocks bits,
seriously?!?!?
 |
| Really,?!? FUCKING REALLY?!?!? |
Now, there’s nothing wrong with the articles themselves but
as has been shown time and time again plenty of people don’t actually read past
the headlines and a quick check of the comments show that we now have
people believing NASA has announced finding life on Mars (although if you can
be bothered to comment why not read the full article)… Unfortunately
rather than being interested in good science communication it appears, yet
again, that the media is only interested in getting website traffic so more
people see some fucking annoying pop-up of a new Volvo or something.
If you’ve actually read this far you won't be surprised to learn that the truth is nowhere near
as exciting as the headlines suggest. Basically NASA has found exactly what it
has expected, but failed, to find since the Viking missions in the 1970’s,
organic macromolecular material. While this could
have a biological origin, there is NO evidence for this! Organic material just
like this is produced abiotically (without life) throughout the universe. We
find very similar molecules in meteorites that have fallen to Earth and the impact of meteorites along
with comets and interplanetary dust particles will have delivered organic
matter to the Martian surface. It has been calculated that 100-300 metric tons
of organic matter is delivered to the Martian surface in this way EACH YEAR.
There are also ways in which the organic matter could have been produced on
Mars itself through hydrothermal or igneous processes. While we cannot rule out
the possibility that these molecules are evidence of ancient life that lived in
the lake these sediments were deposited in this is the least likely source, we
KNOW the other processes would have happened, we have NO EVIDENCE of life.
What I think is the most interesting thing here, and one
that is not really touched on in the paper (presumably because it’s in Science
so they didn’t have the page space) is WHY we have detected these molecules
now? There have been hints of organic matter in previous samples from the
Sheepbed mudstone further up the formation, but these were low responses and
all simple chlorinated molecules, these more complex molecules have been found
in the older Murray mudstones. It is suggested that these, being buried deeper,
have been less exposed to the destructive effects of cosmic radiation, but over
the time periods involved could a little bit less exposure really have saved
them? One of the reasons we hadn’t found complex organic material up until this
point was because it was destroyed during analysis. Minerals in the Martian
soil (such as perchlorates) were releasing oxygen when heated and this caused
the organic material to combust and be lost to analysis (this is what I work
on). For these molecules to be detected now, there must either be more of them
in the sediment or less of the oxidising minerals and it is interesting to
think what processes could have concentrated the organic matter or removed the
minerals in these units…
I’m not going to go into any more detail on the science side
of things, everything I want to say revolves around some unpublished work we’ve
currently got in review and I’m not supposed to discuss that kind of stuff till
it’s out. Needless to say we’ll be getting it back to update it with these
latest findings before it can be published.
Here’s a link to the actual paper in Science
And a nicely put together write up by someone who’s much
better at these things than I am
