Why do ice forms on Mercury despite temperatures up to 400 degrees Celsius?

In theory, the chemicals on the planet's surface are heated by intense solar radiation, releasing water and hydrogen that can then be in deep craters shielded from the sun, where the water is closed. into ice.

The frozen substance was originally discovered in 2011 by NASA's Messenger probe, the first spacecraft to orbit the planet.

The radar image taken by Messenger shows large ice pockets formed in craters on both poles of Mercury.

A team of scientists from Georgia Tech explained how ice formed on the surface of Mercury, because the sun heats hydroxyl compounds in the soil, causing hydrogen and water to be released and moved to the poles.

The discovery is a big surprise that the planet is closest to the Sun in our Solar System, with surface temperatures up to 750 degrees Fahrenheit (nearly 400 degrees Celsius).

The original hypothesis was that ice coming from asteroids that fell to Mercury's surface created craters deep enough to shield the ice from direct contact with the sun.

Because Mercury does not have an atmosphere, its surface temperature drops sharply when it is not exposed to sunlight, dropping as low as minus 280 degrees Fahrenheit (minus 173 degrees Celsius).

While about 90% of the ice is thought to come from asteroids, 10% is formed through natural processes on the planet and a team of researchers from Georgia's Center for Space Technology and Research. Tech has a new explanation.

The soil on Mercury contains many hydroxyl groups, when heated by the solar radiation begin to collide in a process that releases both water and hydrogen molecules.

The ice on Mercury was recorded by NASA's Messenger probe, which became the first spacecraft to orbit Mercury in 2011.

Water and hydrogen are removed from the ground and some groups of molecules move to the poles where they settle to the surface and form layers of ice in craters so they are not exposed to sunlight.

The mechanism of hydroxyl compounds has long been understood, but the Georgia Tech team believes that their work shows how these mechanisms will work on Mercury.

The project is a collaboration between Thomas Orlando (left) and Brant Jones (right) of Georgia Tech."It's a bit like the song Hotel California. Water molecules can check for darkness but they can never leave," Orlando said of the formation of deep ice in Mercury's craters.

"This basic chemical mechanism has been observed dozens of times in studies since the late 1960s. But it's on well defined surfaces."

"Applying that chemical principle to complex surfaces like those on the planet's surface is a groundbreaking study."

The team estimates that through the hydroxyl transformation process, more than 11 billion tons of ice may have formed on the planet in more than 3 million years.

The team believes this process could also help explain how ice can form on an asteroid."Such processes could have made this process," Jones said.

1. The origin of ice and organic matter on Mercury
2. Evidence shows that Mercury is not a dead planet