A haze on Mars seen in 2012 has astronomers baffled, as they try to determine the cause and composition of the system. The presence of the haze, which appeared twice in the same region, was first reported by amateur astronomers. Spacecraft orbiting the Red Planet were unable to view the haze, due to their positions, as well as unfavorable lighting conditions.
The dark material reached as high as 150 miles in the Martian atmosphere, right at the edge of space. This extreme altitude is one of the characteristics of the haze that puzzled scientists the most - such formations were not thought to be possible in such a thin layer of the atmosphere. By comparison, similar features observed previously only rose around 60 miles above the surface.
These dark formations formed in just 10 hours, stretching over an area covering 625 by 300 miles. They constantly evolved over the next ten days before disappearing.
Hubble Space Telescope (HST) images, as well as photographs taken from other observatories and amateur astronomers. Several clouds were seen rising into the atmosphere of Mars, but only to heights of around 60 miles. However, one set of images of Mars recorded on May 17, 1997 showed material rising high into the Martian atmosphere, in much the same manner as the events of 2012. By examining these photographs, astronomers hope to piece together the process that creates these formations.
"One idea we've discussed is that the features are caused by a reflective cloud of water-ice, carbon dioxide-ice or dust particles, but this would require exceptional deviations from standard atmospheric circulation models to explain cloud formations at such high altitudes," Agustin Sanchez-Lavega from the Universidad del País Vasco in Spain said.
Aurora could also play a role in the haze observed over Mars, as they have been observed in the same regions as the haze. These areas are connected with unusual magnetic activity on the Red Planet. If aurora are causing the storms, the process would be 1,000 times more powerful than the effect seen on Earth. Dust kicked up from powerful winds on Mars is not a possible source of the dark hazes, as this material rises, at most, 37 miles into the atmosphere.
The ExoMars Trace Gas Orbiter, could help uncover the reasons for haze conditions. That spacecraft, the first joint mission of the European Space Agency (ESA) and Roscosmos, is due for launch in 2016. Astronomers have detected a small amount of methane in the atmosphere of Mars, but do not know how the gas is produced on the Red Planet. The gas is relatively short-lived in planetary atmospheres, and astronomers want to know how it is being replenished, although biological or chemical processes are possible sources. The ExoMars Trace Gas Orbiter could help answer that question, as well as the mystery of Martian haze.
Analysis of the mysterious Martian haze was published in the journal Nature.
