Scientists have started an experiment to solve one of the most intriguing puzzles in astronomy: the great mystery of Mars methane.
In the next few months they want to find out if the gas has eaten on the red planet in recent years, are of geological origin – or are produced by living organisms.
On Earth, methane is produced mainly by microbes, although the gas can also be produced by relatively simple geological processes underground. The ExoMars Trace Gas Orbiter, which has been moving above Mars for over a year, has been designed to determine which of these sources is responsible for the planet's methane. Last week, sensors were deployed on the ship and began with initial measurements of the planet's atmosphere.
"If we find traces of methane that mix with more complex organic molecules, this will be a strong indication that methane on Mars is a biosuperior. 0 / index.html biological source and that it is produced by living organisms ̵
"However, if we find that it is with gases For example, sulfur dioxide, which will suggest its source, is geological, not biological. In addition, biologically produced methane tends to contain lighter isotopes of the element carbon than methane, which is produced geologically. "
The ExoMars trace gas orbiter was sent to Mars in March 2016 with a proton rocket from the Baikonur Cosmodrome in Kazakhstan. The robot spaceship – a joint European-Russian mission – reached its destination seven months later and gave birth to a small country called Schiaparelli engineered to test heat shields and parachutes in preparation for future landings, however, the lander was destroyed when it crashed after the retro-thruster rockets were shut down too early.
At the same time, the main orb swept as planned into a highly elliptical path around Mars.
Since then, the space engineers have changed this orbit – by repeatedly scavenging the Martian atmosphere – so that the ship orbits the planet 250 miles above the surface. A few days ago engineers directed their instruments at the planet and began to take measurements.
Scientists expect it to be more than a year before they can undertake a full study of the planet's methane hotspots – a good idea if their source is of biological or geological origin.
Astronomers have found evidence of methane on Mars several times. In 2004, Europe's Mars Express orbiter discovered methane in the atmosphere at about 10 parts in a billion. Ten years later, the NASA Rover Curiosity registered the presence of gas on the surface. It is crucial that atmospheric methane decomposes rapidly under ultraviolet solar radiation. His continued presence on Mars therefore indicates that it is replenished from a source somewhere on the planet.
"We will look at the sunlight as it flows through the Martian atmosphere and investigates how it is absorbed by methane molecules," said Håkan Svedhem, orbiter's project scientist. "We should be able to detect the presence of the gas with an accuracy of one molecule per 10 billion molecules."
If methane is detected biologically, two scenarios have to be considered: either long-extinct microbes that disappeared millions of years ago have left the methane behind to reach the surface slowly – or some very resistant methane-producing organisms survive in the underground. "Life could still cling to the Martian surface," Svedhem said.
However, if the gas is of geological origin, the discovery could still have important implications. On Earth, methane – geologically – is produced by a process known as "serpentineization," which occurs when olivine, a mineral found on Mars, reacts with water.
"If we produce methane by geochemical processes on Mars, that will at least indicate that there must be liquid water below the surface of the planet – and since water is vital to life as we know it, that would be one Good news to those of us who hope to one day find living organisms on Mars, "said McCaughrean.