When we send a mission to Mars to search for ancient life, where should it land?
A crater filled with glass…
yes, GLASS… might be a good place to start.
Hello, I’m Ian O’Neill, space producer for Discovery News and today I wanted to take
a quick trip onto the tantalizing surface of Mars.
As depicted in the AWESOME-looking trailer for the new Matt Damon movie “The Martian,”
the Red planet looks like a barren and poisonous place.
To survive, Damon’s character, astronaut MARK WATNEY, must “science the shit” out
of his temporary habitat to survive after being left for dead by his crew.
But as our armada of space robots are showing us, Mars hasn’t always been the dry and
deadly environment it is now -- Mars was once a wet world containing the ingredients for
life and it looks like meteorite craters may be the best place to look for any ancient
lifeforms that could have evolved millions of years ago.
We all know that the Red Planet is littered with craters and interesting geological features,
and it just so happens that NASA’s getting very familiar with the minerals that cover
the Martian surface.
In new research, one particular instrument on board NASA’s Mars Reconnaissance Orbiter
called CRISM has been used to look deep into a few impact craters to look for glass.
But why glass?
Well, in 2014, researchers headed by Brown University found glass deposits at the bottom
of an Argentinian meteorite impact crater that was formed millions of years ago.
Entombed inside this glass was organic material that was existing at the site when the meteorite
hit Earth.
Glass can form when minerals in rock are exposed to sudden heating -- so the extreme impact
pressures and searing heat generated during a meteorite impact can produce certain types
of glasses.
Like those Jurassic era mosquitos entombed inside amber, any ancient organic matter can
be “frozen in time” within this glass, providing us with a cool look into a biological
time capsule dating back millions of years.
So, by turning their gaze to Mars, researchers pondered whether Mars also has glass in its
craters, potentially also containing biosignatures of hypothetical ancient Mars life.
But the spectroscopic signature of glass on Mars is very hard to detect.
In an effort to confront this, the Brown team put similar powdered minerals found on Mars
into an oven and heated it to form glass in the lab.
They then studied light reflected off the lab glass to measure its spectroscopic fingerprint.
Then, using CRISM, the researchers sought out regions on Mars that generated a similar
fingerprint when compared with the lab sample.
And then they saw it, craters on Mars containing glassy material!
The most exciting thing is that one of the craters found to contain glass is HARGRAVES
CRATER near NILI FOSSAE, a 400-mile-long trough in the Martian surface.
And it just so happens that this is one of the landing site options for NASA’s Mars
2020 sample return mission.
Should the rover find glass in that area, and might we be able to analyse the stuff
the samples contain, could the glass have the fossilized remains of ancient Mars microbes
inside?
Who knows, but it would be cool to find out.
Do you think we should send a manned expedition to search for Mars fossils?
Let us know what you think in the comments below, and if you’re interested in how we’re
currently looking for Mars life, check out Amy’s recent video.