Mercury is the closest planet to the Sun. However, there is ice. How is it possible? It is hard to believe that ice exists on a planet where daytime temperatures reach 400ºC. Now, a team of scientists from the Georgia Institute of Technology affirms that the heat from the Sun is what probably helps to produce that ice, on a planet where, logically, we would not expect to find it.
How is ice formed with the help of the Sun?
While roughly 90% of the planet’s ice is believed to come from asteroids, 10% was formed through natural processes on the planet, and the researchers came up with a new explanation for this process. According to the theory, chemicals on the planet’s surface are heated by intense solar radiation, releasing water and hydrogen that can then resettle in deep craters protected from the scorching temperatures of the sun, where water turns into ice.
The frozen substance was originally discovered in 2011 by NASA’s Messenger probe, which was the first spacecraft to orbit the planet. Radar images from the space probe showed large pockets of ice embedded in craters at both of Mercury’s poles.
Brant Jones, a researcher at the Georgia Tech College of Chemistry and Biochemistry and first author of the study, said that this idea is not as strange or as crazy as it might seem. While it’s a bit tricky, it’s all about basic chemistry. The model presents a feasible path for water to emerge and accumulate like ice on a planet filled with all the necessary components.
Did you know that there is more ice on Mercury than on the Moon?
The extreme daytime heat of the planet combined with super cold temperatures (-200 ° C) in the permanently shaded craters could be acting as an “ice-making chemistry lab.”
“The basic chemical mechanism has been observed dozens of times in studies since the late 1960s,” Jones clarified. “But that was on well-defined surfaces. Applying that chemistry to complicated surfaces like those on a planet is groundbreaking research .”
The minerals present on the soil surface of Mercury contain what are called hydroxyl groups. The extreme heat from the Sun helps release these hydroxyl groups and then energizes them to collide with each other to produce hydrogen and water molecules that lift off the surface and travel around the planet. Some water molecules are broken down by sunlight and dissipated, but others land near Mercury’s poles in deep craters that are shielded from the Sun. The molecules get trapped in this dark corner and become part of the growing permanent glacial ice. lodged in the shadows.
The team estimates that through the hydroxyl transformation process, more than 11 billion tons of ice could have formed on the planet over 3 million years. “The process could easily account for up to 10 percent of Mercury’s total ice.” Scientists believe this process could also help explain how ice could form on an asteroid. “Processes like these could have helped achieve this,” concludes Jones.
Referencia: B. M. Jones, M. Sarantos, T. M. Orlando. A New In Situ Quasi-continuous Solar-wind Source of Molecular Water on Mercury. The Astrophysical Journal, 2020; 891 (2): L43 DOI: 10.3847/2041-8213/ab6bda
