The artist’s imagination depicts the early Martian atmosphere (right) – which is believed to have liquid water and ga atmosphere – as opposed to the cold, dry atmosphere on Mars today (left). Credit: NASA’s Goddard Space Flight Center
New University Ari Rizona-led research updates our understanding of how water comes out Mars – Leakage is not like a faucet but with a sudden splash.
Mars once had oceans but is now bone-dry, leaving many wondering how the water was lost. Researchers at the University of Arizona have discovered a surprisingly large amount of water in the upper atmosphere of Mars, where it is rapidly disappearing, explaining part of the mystery of Mars.
Shane Stone, a graduate student at the Lunar and Planetary Laboratory in Eurasia and the lead author of a new paper published in Science, describes himself as a planetary chemist. Once a laboratory chemist who helped develop a polymer that could be used to more effectively wrap and deliver therapeutic drugs, he now studies the chemistry of planetary atmospheres.
Since 2014, he has worked NASAMars is short for atmospheric and volatile evolution. The MAVEN spacecraft began orbiting Mars in 2014 and has been recording the formation of the atmosphere above the Earth’s planetary neighbors ever since.
“We know that there was liquid water on the surface of Mars billions of years ago,” Stone said. “There must have been a ga atmosphere atmosphere, so we can know that Mars somehow loses most of its atmosphere in space. Maven is trying to characterize the processes responsible for this damage, and part of it is understanding exactly how Mars lost its water. “
Co-authors of the study include Eurizo’s professor of planetary science and Stone’s research adviser, as well as Eurizo’s professor of planetary science and research at the Center for Research and Exploration at Space Science and Technology in Maryland.
Looking for water
As Mars orbits, it sinks into the planet’s atmosphere every 4 1/2 hours. The onboard NGIMS instrument – short for neutral gas and ion mass spectrometer – is measuring the abundance of water molecules called ions in the atmosphere of Upper Mars, about 100 miles from the planet’s surface. From this information, scientists can estimate how much water is in the atmosphere.
MAVEN and. Previous observations using Hubble Space Telescope Showed that the loss of water from the Martian upper atmosphere varies with the asons. Compared to Earth, Mars takes a more elliptical path around the Sun and is closer to it during the summer in the Southern Hemisphere.
Stone and his team observed that when Mars is closer to the sun, the planet warms up, and more water – found on the surface in the form of ice – goes into the atmosphere above the surface where it is lost in space. This happens every Tuesday in a year or about once every two Earth years. Regional dust storms that occur on Mars every Tuesday and global dust storms that occur on the planet about once every 10 years further heat up the atmosphere and increase the upward movement of water.
Stone said the processes that make cyclic movement possible contradict the classical picture of saving water from Mars, showing that it is incomplete. According to the classical process, ice formed from water is turned into gas and destroyed by the sun’s rays in the lower atmosphere. However this process will play as a slow, steady trick, not affected by dust tuo or dust storms, which cannot mesh with current observations.
“This is important because we didn’t expect to see any water in the atmosphere above Mars,” Stone said. “If we compare Mars with Earth, the water on Earth is limited to the surface because something is called a hygropos. It is just a layer in the atmosphere that is cold enough to condense (and therefore close) any water vapor traveling above. “
The team argues that what should be the highgroup ause of Mars is moving water past, which is too hot to stop water vapor. Once in the upper atmosphere, water molecules break down very quickly through ions – within four hours, they count – and are lost in space after the byproducts.
“Water damage to its atmosphere and space is one of the main reasons why Mars is colder and drier than hot and humid Earth. Maven’s new data reveals a process by which this damage continues to occur today,” Stone said.
A dry and dusty world
When the team released their findings 1 billion years later, they discovered that the process was responsible for the loss of about 17 inches deep in the global ocean.
“If we take water and spread it evenly over the entire surface of Mars, the new process we describe is because of that water being lost in that ocean space,” Stone said. “An additional 6.7 inches will be lost due to the impact of global dust storms alone.”
During global dust storms, 20 times more water can be transported into the upper atmosphere. For example, a global dust storm lasting 45 days released as much water into space as Mars would lose during a quiet Mars year or 687 Earth days.
And while Stone and his team will not be able to do extrapolation more than 1 billion years ago, he thinks the process may not work the same way as before, as Mars may have been hygroposed much earlier.
“Before we can begin the process described, there must already be a significant amount of atmospheric participation in space,” Stone said. “We still need to nail the effect of this process and when it started working.”
In the future, Stone will want to study the atmosphere Sat.Moon Titan.
Titan has an interesting atmosphere in which organic chemistry plays a significant role, Stone said. “As a former synthetic organic chemist, I look forward to investigating these processes.”
Reference: Shane W. Stone, Roger V. , Science.
DOI: 10.1126 / science.ba 5229
