Martian water loss documented
25 Oct 2016 by qmjwtjwqdb.d qmjwtjwqdb.d
The amount of hydrogen – and therefore water - ejected from Mars is dependent on the proximity of the Red Planet to the Sun as it orbits, scientists have discovered.
The amount of hydrogen – and therefore water - ejected from Mars is dependent on the proximity of the Red Planet to the Sun as it orbits it.
Hydrogen in Mars’ atmosphere is created when water vapour in the lower atmosphere is broken apart by sunlight. Measurements captured by the Mars Atmosphere and Volatile Evolution (MAVEN) revealed when Mars was closest to the Sun more hydrogen – up to 10 times as much - was lost then when it was furthest away.Ali Rahmati, from the University of California at Berkeley and a MAVEN team member said: “MAVEN is giving us unprecedented detail about hydrogen escape from the upper atmosphere of Mars, and this is crucial for helping us figure out the total amount of water lost over billions of years.”
It is believed several processes on the Red Planet’s atmosphere may act on hydrogen, leading to it escaping. Originally researchers believed hydrogen release from Mars was in a constant flow until four of MAVEN’s instruments detected the tenfold increase in the rate of escape.
Scientists know that Mars’ elliptical orbit causes sunlight intensity varying by almost 50% over the course of a Martian year – 687 days. The Martian seasons also affects how much water vapour is present in the lower atmosphere as well as how much makes it into the upper atmosphere.
Rahmati said: “MAVEN’s findings reveal what is happening in Mars’ atmosphere now, but over time this type of loss contributed to the global change from a wetter environment to the dry planet we see today.”
The scientists will continue to make observations for another Martian year, as the project has been approved until at least September 2018. These findings were presented at the joint meeting of the Division for Planetary Sciences and the European Planetary Science Congress in California last week.
