The National Aeronautics and Space Administration (NASA) reveals the Top 10 findings of its MAVEN (Mars Atmosphere and Volatile Evolution Mission). On June 17, NASA MAVEN celebrated its 1,000 Earth days in orbit around the Red Planet.
Foremost, NASA launched the mission in November 2013. It reached the Martian orbit in September 2014. Here are the Top 10 MAVEN discoveries on Mars:
1. The Martian atmosphere has been stripped away by the sun. Over time, the solar wind caused the early warmer and wetter environment on Mars. It eventually turned into the cold, dry planet that we know today.
2. MAVEN successfully measured the rate of atmosphere deterioration due to the solar wind. The removal process is now better understood as well. Stronger solar wind and the ultraviolet light indicate that large amounts of gas have been lost to space through time.
3. According to Science Daily, isotopes in the upper atmosphere were used to measure the loss of gas. Isotopes are atoms of the same composition but having different mass. Findings show that more than 2/3 or more of the atmosphere in Mars have vanished.
4. Scientists were able to observe the full seasonal variation of hydrogen in the upper atmosphere. It varies by a factor of 10 throughout the year. The source of the hydrogen is water in the lower atmosphere, split into hydrogen and oxygen by sunlight.
5. On the other hand, the interactions between the solar wind and the planet are due to the lack of a Martian magnetic field. The magnetosphere that results from the interactions varies on short timescales. As a result, it is quite "lumpy".
6. Per Astrobiology, MAVEN discovered two new types of aurora: the "diffuse" and the "proton". However, they are different from humans see aurora on Earth. the variations on Mars are unrelated to either a global or local magnetic field.
7. These aurorae are caused by an influx of particles from the sun ejected through solar storms. They then hit the atmosphere in Mars. Thus, they increase the rate of loss of gas to space.
8. First direct observations of a layer of metal ions in the Mars were made. Experts found that this layer is always present. Nevertheless, it was enhanced dramatically by the close passage of Comet Siding Spring in October 2014.
9. It is now known that part of the particles from solar winds could penetrate "unexpectedly" into the upper atmosphere. Before, it was believed that they are being diverted around the Martian ionosphere. The penetration is allowed by chemical reactions that turn the charged particles of the solar wind into neutral atoms.
10. Brilliant Imaging of the distribution of gaseous nitric oxide and ozone in the atmosphere reveals another complex behavior. Apparently, there are dynamical processes of exchange of gas between the lower and upper atmosphere. These are not yet understood at the moment.
