Mars' global dust storms may have big effect on atmosphere loss
Every so often, Mars experiences a dust storm that spans the entire planet — a global dust storm, one that may contribute to the loss of gas from the Red Planet's atmosphere. The possibility was discussed in a newly published study, which looked at data gathered by the NASA Mars Reconnaissance Orbiter, also known as the MRO. The most recent global dust storm happened on Mars back in 2007.
Long ago in the planet's history, Mars was a warmer, wetter place. That changed over a long period of time, though, as gas escaped Mars' atmosphere, ultimately resulting in the barren frozen planet we see today. The image below shows a calm Mars on the left, and Mars with dust everywhere thanks to a global dust storm on the right.
In past years, the European Space Agency via its Mars Express orbiter and NASA via its Hubble Space Telescope found a link between water vapor in the planet's middle atmosphere and the loss of hydrogen from the top of the atmosphere. This new study, which was recently published in Nature Astronomy, reports a connection between higher levels of water vapor in Mars' middle atmosphere and dust storms.
The researchers point toward the rising air mass that takes place during dust storms and the water vapor that is carried up with it. However, the two space agencies' observations of middle atmosphere water vapor and gas escape took place during years of relative calm, having happened after the 2007 global dust storm.
That's what makes this year so exciting — it'll see the start of a new global dust storm on Mars. Such a storm would give NASA a chance to gather loads of data during the event using the various equipment it has at Mars. Data on regional Mars dust storms already points toward an increase in middle atmosphere water vapor, according to researchers, and existing data from the 2007 global storm hint at a huge increase in that water vapor during the event.
A new global dust storm won't be without its issues, though. Researchers anticipate that once the next global storm starts this upcoming summer, it'll continue on through early 2019, resulting in months of potential issues for some existing Mars missions. The Opportunity rover, for example, relies on solar panels for power, which the dust will interfere with.
SOURCE: NASA