Mars Orbiter ExoMars-TGO not found methane in the atmosphere of the red planet

Spacecraft Trace Gas Orbiter (TGO) European-Russian ExoMars mission work on the orbit of the red planet for a year. During this time he managed to do many useful things: made a more detailed map of the distribution of water under the surface of the planet, studied the effect of global dust storms on the atmosphere of Mars, as well as… found no traces of methane in its atmosphere that deepened the mystery of its opening tools the Rover “Kyuriositi” the U.S. space Agency NASA and the sensor probe Mars Express of the European space Agency (ESA), as reported previously.

The discovery of methane on Mars has become a sensation. On Earth, almost all the stocks of this gas in the atmosphere are of biological origin (part, however, is associated with geochemical processes), and it is rapidly destroyed by the interaction of its molecules with sunlight and oxygen. For this reason, many scientists made the assumption that the source of Martian methane could be Martian microbes.

Just last week, NASA and ESA announced that the Curiosity Rover and the Orbiter Mars Express has discovered large emissions of methane every single day in 2013 and were even able to triangulate the most likely source of emissions. However published the journal Nature the results of the latest observations of the spacecraft TGO show a very different picture of the content of this gas in the atmosphere of the red planet.

The researchers analyzed data of the Trace Gas Orbiter (TGO), collected between April and August last year. To improve the accuracy of measurement of concentrations of trace gases TGO uses the method of solar eclipses — measures the absorption spectrum of the atmosphere at sunset and sunrise. This reduces the noise level in the spectrum is removed and ten times to increase the optical path of the rays (i.e. the volume of the atmosphere, which measured gas concentrations). These measurements Orbiter conducts with the help of spectrometers ACS and NOMAD.

Despite the relatively short duration of observations, the probe can measure the concentration of methane is almost a hundred points above the surface of the red planet. Most of these dimensions refers to the Subpolar regions, however, several points are captured and Equatorial latitudes, in particular the area of the Gale crater where the Curiosity Rover found a large release of gas into the atmosphere. Analysis of the data shows that in all these points TGO noted a concentration of not more than 0.15 ppb volume with respect to the error. It’s a hundred times less data Mars Express and ten times less data “Curiosity”.

Map of the area, the investigation of which was doing the TGO to calculate the concentration of methane in the atmosphere

“We increased the accuracy of measurements by several orders of magnitude compared to the SAM instrument onboard the Curiosity Rover. We managed to find traces of water in the extremely dry atmosphere of Mars, but we didn’t find even minimal amounts of methane, which would be above the level of background noise, not to mention those quantities that were recorded by NASA Rover”, says one of the supervisors of the mission ExoMars-TGO Oleg Korablev from the space research Institute of RAS.

“We do not criticize measurements that were conducted by other teams – you need to understand that we were monitoring last summer and fall, and the Rover and the probe five years ago. On the other hand, it’s even harder to explain the fact, which could disappear this methane, given the mechanisms that can destroy it”, — adds the scientist.

In mid-2018 to Mars dropped a global dust storm, which cost the “life” of one of the Mars Rovers space Agency NASA is “opportunity“. Watching this event from above, the Orbiter TGO had a great opportunity to understand what impact such giant storms have on the atmosphere of the planet. Data analysis was done by another group of scientists under the leadership of Ann Vandal. The results of their study were also published in the journal Nature.

The volume concentration of water and “semi-heavy” water, and their attitude depending on height. Lines of different colors describe different aspects about the storm on 30 may

Scientists conducted measurements of the vertical distribution of dust, water, and “semi-heavy” water (in its molecules contains one atom of hydrogen and deuterium) to a height of 90 kilometres above the surface. Data analysis showed that before the dust storm of may 30, 2018 “semi-heavy” water is almost gone from the heights more than 40 kilometers, which indicates that the process of the formation of water-ice clouds. However, during the storm this concentration again increased, which suggests that the newly formed cloud is heated, melted and destroyed. Scientists say that these processes could further accelerate the circulation of substances in the atmosphere.

Water contains not only in the atmosphere of the red planet, but beneath its surface. Tool FREND probe TGO from may to September last year, performed several scans of the surface of Mars, allowing scientists were able to update the global map of the distribution of water in the soil to a depth of 1 meter. Using the tool was carried out the observation of how cosmic rays interact with the surface. In particular, the device measured the speed of reflection (rebound) of neutrons from the surface of the contained in the form of ice, hydrogen and hydrated minerals they slow down, allowing the apparatus to determine the quantitative content of water in a particular region.

A map of the distribution of subsurface water on Mars, created using TGO

The results were similar with the findings of previous observations. The largest concentration of water is in the polar regions (in particular, near the North pole of the planet), while the rest of the planet is covered by alternating “wet” and “dry” regions. The tool FREND is not yet complete, but scientists have got the most detailed map of the distribution of water on the planet.

“In just 131 days tool we have managed in a much more detailed map than the one that was based on 16 years of observations by the spacecraft Mars Odyssey,” — says Igor Mitrofanov, lead author of the study detailing the distribution of water on Mars.

“Data is constantly replenished. Over time, we get a full map of the distribution of subsurface Martian water. This is important not only to determine the water-rich regions of the planet, but also for understanding the General evolution of Mars. In addition, the data will be useful for future missions to study the red planet”, adds the scientist.

Discuss this article in our Telegram chat.

Leave a Reply

Your email address will not be published. Required fields are marked *