Mars rovers are great for many reasons, most importantly, because they allow us to live vicariously through a hunk of metal exploring the Red Planet. NASA's currently working on a yet-to-be-named rover mission slated for 2020, and is in the process of narrowing down a landing location. Similarly, the European Space Agency (ESA) has just announced that it's debating two locations for its 2020 ExoMars rover, which will search for signs of ancient life. Image: ESA/ATG medialab
"While all three sites under discussion [by ESA] would give us excellent opportunities to look for signatures of ancient biomarkers and gain new insights into the planet's wetter past, we can only carry two sites forward for further detailed analysis," Jorge Vago, ESA's ExoMars rover project scientist, said in a press release. "Both candidate sites would explore a period of ancient martian history that hasn't been studied by previous missions."
Texture map for Oxia Planum. Image: NASA/JPL-Caltech/Arizona State University; analysis: IRSPS/TAS-I
The two sites in question, Oxia Planum and Mawrth Vallis, lie just north of the equator, and both feature geologic deposits that are thought to have formed under wet conditions at some point in Mars' distant past. Besides the fact that places preserving a history of ancient oceans are a solid choice for alien hunting, both locations are relatively low in elevation, which will afford ExoMars enough atmosphere to help it slow down during its parachute descent.
Oxia Planum is thought to have beds of clay-rich minerals, as it's believed that about 3.9 billion years ago, several streams of water flowed into this region. Just a few hundred kilometres away, Mawrth Vallis exhibits similar clay-rich deposits, according to observations from orbit. The ESA expects to have a finalised decision about the landing site a year before the big launch.
The ExoMars rover is part of a series of Martian missions by the ESA and Russia's Roscosmos State Corporation. Last year, the ExoMars Trace Gas Orbiter reached Mars' atmosphere, which it will soon begin to scope out for methane and other atmospheric gases that could reveal some sort of biological activity, past or present. This next instalment will get down and dirty on the surface of the Red Planet itself, and beam information back to Earth via the Trace Gas Orbiter. That's assuming, of course, that the ExoMars 2020 rover landing goes more smoothly than ill-fated Schiaparelli landing attempt this past spring.
With all this impending Mars exploration, someone better find something good on that planet. No pressure, though.