According to the conclusions of a new study from experts in the United States, it would appear that Medusae Fossae Formation on the surface of Mars has a volcanic origin. How this landscape feature formed has puzzled planetary scientists for years.
The structure is basically a 1,000-kilometer (620-mile) deposit located close to the Martian equator. Scientists with the Smithsonian Institution's National Air and Space Museum's Center for Earth and Planetary Studies (CEPS) believe that it was produced by volcanic ash.
One of the reasons why studying this formation was so difficult is that it is covered by a very thick layer of dust throughout, making it impossible to conduct orbiter-based studies of its origins. Since no space agency has a rover in the area, the issue was left unresolved.
The dust completely obscured the surface of the landscape feature from spectrometers, the instruments used to assess the chemical composition of objects based on the light they reflect back into space. As such, astronomers had no way of knowing what the Medusae was made up of.
CEPS researcher Jim Zimbelman was the leader of the investigations team. Details of how the study was conducted were published in the May 24 issue of the top journal Science, Space
In the international scientific community, the main points of view circulated thus far were that the formation was either a massive mound of compressed volcanic ash, or a structure made up of consolidated dust, brought to that location by strong winds.
Others still suggested that the thick layer of dust on the surface might in fact cover up a huge water ice deposit, while others said that the Medusae could have resulted from the activities of an ancient ocean that might have existed at that location.
The volcanic ash theory earned more credibility in the new study because the team was able to refine the age of the structure, pushing it an additional 2 billion years into the planet's past. Until now, experts thought the formation to be around 1.6 billion years old.
While these findings do not represent concrete evidence that the Medusae is made up of volcanic ash, it does provide some insight into the mechanisms that may have led to its formation. However, until we can study the structure on site, there is no way of knowing for sure what its origin may be.
Fortunately, the formation is located close to Gale Crater and Mount Sharp, where the Mars Science Laboratory (MSL) rover Curiosity is scheduled to land on August 5.