‘Red Ginkgo’, local dust storm on Mars also contributed to evaporation of ancient water
Occurs every summer in the Southern Hemisphere… Proof of simultaneous observation of 3 satellites including MRO
(Seoul = Yonhap News) Reporter Eom Nam-seok = ‘Red Planet’ Mars is a cold and barren place where you can’t find a drop of water on its surface, but it is said that billions of years ago, it had oceans, lakes and rivers just like Earth. It is presumed that much of the water escaped into space through the atmosphere, and small local dust storms have also been proven to play a role in this evaporation.
According to the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, an international team of researchers led by Michael Chapin, a researcher at the University of Colorado’s Atmospheric and Space Physics Laboratory in Boulder, is based on observations collected simultaneously by three satellites orbiting Mars. A study proving the contribution of this water evaporation was published in the scientific journal Nature Astronomy.
Dust storms on Mars heat the cold upper atmosphere, causing water vapor to rise higher without freezing. Here, water molecules (H₂O) are exposed to ultraviolet radiation as they are and are separated into hydrogen (H) and oxygen (O) atoms, and hydrogen, the lightest element, escapes into space first and loses water.
Scientists have hypothesized that this process may have caused the Martian water to evaporate as large dust storms sweeping across the planet every three to four years Mars time, combined with summer in the southern hemisphere, when Mars gets closer to the Sun.
But it was not known whether localized small dust storms, which occur almost every summer in the Southern Hemisphere, play a role.
Using satellite data, the team found that small, localized dust storms in the southern hemisphere in summer doubled the amount of water loss compared to otherwise.
The research team found that three satellites, including NASA’s Mars Reconnaissance Orbiter (MRO), atmospheric probe ‘MAVEN’, and European Space Agency’s ‘Gas Tracking Orbiter’ (TGO), were launched in the Southern Hemisphere in January and February 2019. Data from simultaneous observations of local dust storms were used.
The MRO measured the concentration of ice made of dust and water with temperature changes up to 100 km above the surface of Mars, while the TGO measured the concentration of water vapor and ice at the same altitude. Maven measured the amount of hydrogen presumably separated from water molecules up to 1,000 km above the ground.
As a result, the TGO’s spectrometer only captured water vapor in the low-altitude atmosphere before the onset of the dust storm, but after the onset of the local dust storm, as the atmosphere heated, it detected water vapor at higher altitudes.
TGO observatories captured ten times as much water in the mid-altitude atmosphere as the dust storm began, exactly consistent with temperature data measured by the MRO’s infrared radiometer. The radiometer showed that the temperature rose as the dust flew high.
Ice clouds also appeared to have disappeared, confirmed by Maven’s ultraviolet spectroscopic images.
Maven images show that ice clouds formed over Tharsis before the dust storm, but disappeared completely during the dust storm and re-formed after the storm was over.
Maven observations also confirmed that at higher altitudes, water molecules break down into hydrogen and oxygen atoms, resulting in a 50% increase in hydrogen.
Researcher Chapin said, “Without one hydrogen atom, the remaining hydrogen and oxygen cannot become water molecules, so water can be lost forever with just one hydrogen atom.” For the first time, he said, “I got a grip on how the whole system works.”