Two possible landing sites for ExoMars mission

March 29, 2017 by Laurence Coustal
The ExoMars mission

The ExoMars mobile rover, tasked with recovering evidence of life on the Red Planet, will touch down in 2021 at one of two sites, scientists announced Wednesday.

"After intense discussions, we have voted for the sites Oxia Planum and Mawrth Vallis," Frances Westhall, head of research at the Center for Molecular Biophysics in Orleans, France, told journalists.

The final decision—to be made a few months before the 2020 lauch—will in some ways pit scientists against engineers: one site is more varied geologically, while the other is less rocky, and thus easier for the rover to navigate.

Both locations, however, are rich in clay, which makes them promising environments "that may contain traces of past life," said Westhall, a member of the Mars Analogue for Space Exploration (MASE) consortium.

"We like clay because it attracts organic matter and preserves it."

Life forms are unlikely to exist on Mars' barren, radiation-blasted surface.

But traces of methane in the planet's atmosphere suggest something may have once stirred under the surface, possibly single-celled microbes.

The multi-billion dollar mission will look for signs of life from Mars ancient past when it had water, at least 3.6 billion years ago.

The compact car-sized rover—equipped with a drill, wheels and legs—is designed to execute eight excavations over a six month period, travelling a total of a dozen kilometres (seven or eight miles) in the process.

And the winner is...

It will dig to a depth of two metres (six feet) twice, and to a depth of 1.5 metres (four-and-a-half feet) six times.

Onboard instruments will analyse the samples to look for signs of past life.

One problem, however, is that scientists are not sure what they are looking for.

Unlike Earth, Mars essentially lacks oxygen, an essential ingredient for most on our planet.

To anticipate what microscopic fossils of anaerobic organisms on the Red Planet might look like, Westhall and her team did experiments.

"In the laboratory, we tried to duplicate the likely conditions of ancient Mars in terms of temperature, mineral composition and atmosphere," she said.

The candidate landing sites are cratered, and at low altitudes, to ensure that the rover's parachute will have time to open properly.

The two-part mission saw a spacecraft successfully placed into orbit in mid-October, but a companion lander designed to pave the way for a mobile-lab rover in 2020 smashed into the planet's surface.

So will it be Oxia Planum or Mawrth Vallis?

"There is always a tug-of-war between the engineers and the scientists, because the latter want to go where things are interesting, and the former are generally more interested in a safe landing," Westhall joked.

Explore further: Image: ESA's ExoMars rover and Russia's stationary surface science platform

Related Stories

Image: Mawrth Vallis Martian mosaic

September 27, 2016

Sculpted by ancient water flowing on the surface, Mawrth Vallis is one of the most remarkable outflow channels on Mars. The valley, once a potentially habitable place, is one of the main features of a region at the boundary ...

Computer glitch blamed for European Mars lander crash

November 24, 2016

A tiny lander that crashed on Mars last month flew into the Red Planet at 540 kilometres (335 miles) per hour instead of gently gliding to a stop, after a computer misjudged its altitude, scientists said.

Recommended for you

Solar-powered rover approaching 5,000th Martian dawn

February 16, 2018

The sun will rise on NASA's solar-powered Mars rover Opportunity for the 5,000th time on Saturday, sending rays of energy to a golf-cart-size robotic field geologist that continues to provide revelations about the Red Planet.

Supermassive black holes are outgrowing their galaxies

February 15, 2018

The growth of the biggest black holes in the Universe is outrunning the rate of formation of stars in the galaxies they inhabit, according to two new studies using data from NASA's Chandra X-ray Observatory and other telescopes ...

Hubble sees Neptune's mysterious shrinking storm

February 15, 2018

Three billion miles away on the farthest known major planet in our solar system, an ominous, dark storm - once big enough to stretch across the Atlantic Ocean from Boston to Portugal - is shrinking out of existence as seen ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Mar 30, 2017
Surely if they are cratered they would naturally be devoid of any life.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.