OAS NOVEMBER 20013 ASTRONOMY EZINE VOL 2 | Page 39

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Much closer to home, astrobiology is helping pull together disparate fields of scientific inquiry. As the
Curiosity rover hauls its bulky science laboratory around the surface of Mars, it is scouring the dusty
terrain at the beck and call of geologists, geochemists, planetary scientists, atmospheric chemists, and
even biologists.
This rover’s ground truth, and the wealth of data from other rovers and missions – from Spirit and Opportunity to the Phoenix polar lander, and great orbital craft such as the Mars Reconnaissance Orbiter
and Mars Express – is creating a picture of Mars that speaks to a rich, wet, history that could have been
more amenable to life. Right now there is also good evidence of seasonally varying water runoffs from
subsurface ice or aquifers, and for the presence of all the base elements for life. As of yet though there is
no smoking gun that points to living things on Mars; no complex organic molecules have been detected,
and there are conflicting measurements of atmospheric methane, a molecule that would be a potent signal of metabolic activity.
On the other hand, since the Viking missions of the 1970’s there have been no instruments on Martian
soil with the specific abilities to test for the presence of live organisms or their direct fossil presence. A
proposed NASA rover, Mars 2020, might change that, and might even prepare samples for eventual return to Earth.

Image: Mike Greenham

biochemistry. Also, although the modern Earth
Here, on the home planet, an array of new technol- may be a poor representative for Earth’s state
ogy and new thinking is being brought to bear on throughout its 4.5 billion year history, we’re getscientific questions that reach out to some central ting pretty good at unraveling the paleontological
and profound aspects of the search for life. What
and geophysical clues to its past, and the relationare life’s origins? How does life take over a plan- ship to life’s remarkable pathway.
et? How does complex life arise? How does the
human microbiome influence our evolution, and
But I think, again, that the most profound shift has
how does the planet-wide microbiome influence
come from, and will continue to come from, our
our entire environment?
newly found knowledge of worlds around other
suns. To put it quite simply; here finally is the opThese are tough topics, but our increasingly good portunity to expand our sample size beyond a sinability to manipulate the microscopic world of at- gle planet, and beyond a single planetary system.
oms and molecules, and our still growing computational capacity is making inroads. We’ve made
That is a huge leap, which is already influencing
the first ‘artificial’ life (or at least cobbled together our thinking. Papers are now written that compare
a franken-organism of sorts), and chemists are
our circumstances to those of other worlds, and
studying an array of possible routes that lead from unlike such efforts in the past, we actually have
simple molecules to the emergent complexity of
real data to go on. For example, a few months ago

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