Dust storms in Mars play a significant role in facilitating the escape of gas from its atmosphere, a new study finds.
Mars, A Dry Planet
It is known now that in ancient past, water flowed on the Red Planet’s surface. It is backed by evidence from canyons, riverbeds, and water-soaked minerals like hematite. Scientists, however, do not know why the planet dried up.
One of the most accepted theories is that solar wind stripped the majority of the atmosphere on Mars, following its magnetic field loss around 4 billion years ago. The air on Mars became so fine that it could not support running surface water anymore. Now, the research team suggests they have understood how the planet might have lost its atmosphere.
Link Between Atmospheric Loss And Dust Storms
To conduct the study, a team of researchers reanalyzed the observations of a dust storm that NASA’s Mars Reconnaissance Orbiter had made. MRO had seen water vapor rise in the middle of the atmosphere, around 30 to 60 miles high when regional dust storms took place.
The data showed that the vapor shifted to a higher height and rose in volume by over a hundred times.
"We found there's an increase in water vapor in the middle atmosphere in connection with dust storms," said Nicholas Heavens, study lead author and a geophysicist at Virginia’s Hampton University. "Water vapor is carried up with the same air mass rising with the dust."
Other observations made by the European Space Agency’s Mars Express orbiter and NASA’s Hubble Space Telescope suggest that there is a relation between the middle-atmosphere water volume on Mars and atmospheric hydrogen escaping into space, at least during the time when global dust storms do not take place. The team still does not know what the link is during the years when global dust storms take place because they do not happen too often.
Study coauthor David Kass feels that having a global dust storm on Mars would be good because scientists will then be able to understand the phenomenon better. However, a global dust storm on the Red Planet could have an adverse impact on the missions that are currently going on there. For instance, the Opportunity mission, which is powered by solar energy, would have to be sheltered to save power.
The upcoming Insight mission would be affected, too, as its entry course has to be altered to ensure safe landing and descent on the planet in November this year. The global dust storm would also lower the visibility for all the cameras on the orbiters and rovers that operate on and around Mars.
The study was published online in the journal Nature Astronomy on Jan. 22.