Oh great, even more water on Mars
Liquid water has been found on Mars! At least, scientists have discovered signs of liquid water. Or rather, some scientists are convinced they’ve found what they believe might be signs of liquid water. On Mars.
And where there’s water, there’s life. Maybe. Mainly what there is, is a heck of a lot of hedging.
Anyway, aspiring astrobiologists are overjoyed at what may or may not be water on the red planet.
Imagine it: a whole lake of the stuff, just waiting for an intrepid scientist to head on over — somehow — and grab a sample to test for signs of life. Tiny Martian micro-organisms. Maybe something even larger. You know, for the braai.
Here’s the catch, though. Or a catch, because as you have probably noticed there are lots of catches. This particular catch is that all of this hypothetical water is trapped about a kilometre underground.
If only there was someone keen on going to Mars who also has a pronounced yet so far frustratingly unfulfilled interest in sending tiny submarines into inaccessible underground bodies of water that would seek out and return safely with actual, living beings.
Here is what we know.
Since its arrival in 2003, the European Space Agency’s Mars Express Orbiter has, among other things, been scanning the planet’s south pole with Marsis (or, as its mother calls it when she’s angry, the Mars Advanced Radar for Subsurface and Ionosphere Sounding).
In radar profiles gathered between May 2012 and December 2015, Marsis turned up “anomalously bright subsurface reflections” that were surrounded by much less reflective areas, according to the team’s research paper, which was published in the journal Science on Wednesday.
This bright spot, approximately 20km across, displayed permittivity properties — which signal the ability of a substance to store energy in an electrical field, and are also apparently detectable through glacier-like strata of polar ice from space — that match those of water-bearing substances, the researchers say. “We interpret this feature as a stable body of liquid water on Mars.”
Humanity, of course, has a long and distinguished history of getting stuff wrong about water on Mars.
In 1884, philosopher-astronomer Percival Lowell founded the Lowell Observatory in Arizona,from which the on-again, off-again planet Pluto was later discovered in 1930.
But another thing Lowell did was go around telling anyone who would listen that there were water canals criss-crossing Mars, built by a once-great and now dying civilisation.
This idea took root in the imagination of a public already enthralled by real-world developments of the Panama and Suez canals, and inspired works of science fiction — most notably in the works of Edgar Rice Burroughs and CS Lewis, but later later HG Wells, Ray Bradbury and even Philip K Dick.
Unfortunately for Lowell, what he thought he saw were not canals at all. Improvements in telescope technology proved as much over the decades that followed. According to science writer Claire F Evans, optometrists who looked into Lowell’s work came to the conclusion that what he was seeing was most likely ... the veins of his own eyeball.
It’s all water under the bridge now, though. Especially considering that in 2012 Nasa’s Curiosity Rover found clear evidence of what was once a flowing stream bed, and more and more recent discoveries have firmed up the idea that Mars was once, and perhaps still is, if not wet then at least occasionally damp.
Still, the Mars Express observations have made quite the splash. The existence of a sizeable body of liquid water under the polar ice cap wouldn’t quite vindicate Lowell, but it has already inspired at least a small amount of wonder.
For a final word, let’s check in with a proper scientist. One unconnected with the ESA’s mission.
Richard Zurek is the chief scientist for the Mars Programme at the Jet Propulsion Laboratory over at Nasa. After reviewing the research team’s work, he told Wired he can’t say unequivocally that it’s 100% definitely water, but he “sure can’t think of anything else that looks like this thing does other than liquid water”.
In other words, if it looks like a duck, and it quacks like a duck, then it’s probably a duck on an underground lake of liquid water.