The temporal atmosphere of Ceres is associated with solar activity

The temporal atmosphere of Ceres is associated with solar activity

Researchers have long believed that Ceres may contain a weak atmosphere. But no one could understand why it periodically disappears. Now its temporality is explained by the solar behavior, and not the distance between them. Scientists used the Dawn apparatus and other ground-based observatories to sort out this issue.

“We believe that the volatility of the atmosphere Ceres is the result of solar activity,” said Michela Villarreal, a researcher at the University of California (Los Angeles).

Ceres is a small object located in the asteroid belt (the area between Mars and Jupiter). When the solar energy particles break on ice near the surface of the dwarf, they give up their energy to water molecules. This frees them from the ground, thanks to which they rise and create a thin atmospheric layer that lasts for several weeks.

Even before the arrival of the vehicle to the dwarf in 2015, the researchers noticed signs of the atmosphere, but also realized that it was temporary. In 1991, the international satellite “Ultraviolet Investigator” found a hydroxyl emission, which was not in 1990. The attempt was repeated in 2007 with the help of the Very Large Telescope, but stumbled upon the void. The Herschel Space Observatory made four attempts and only in three found water in the weak atmosphere of Ceres.

When Dawn took over the case in 2015, the team found enough evidence of water in the form of ice. The top layer of the surface was hydrogen rich. The ice was found in the small bright crater of Oxo, as well as in the crater, which is located in the eternal shade in the northern hemisphere. Abundant ice suggests that the exosphere of Ceres is created in a process that repeats the comet's script. That is, the closer the dwarf is to Sun, the more water vapor is formed. But a new study sweeps away this option. Sublimation may be present, but, most likely, it has no global significance in this case.

The study revealed that the transition atmosphere coincided with higher concentrations of the solar energy protons. Moreover, the closer she came to the Sun, the harder it was to see. It turns out that the main role in the appearance of the atmosphere is played by solar activity, and not distance.

Now Ceres is moving in its orbit to the Sun, which for the next few years will remain relatively calm. The authors claim that at this time the atmosphere of Ceres will disappear or be very weak.

Dawn is located in the expanded mission and moves to a different orbital point, providing new views. The main goal is to measure cosmic rays in order to determine the chemistry near the surface. In late April, the Sun will be located behind the ship (it is 20,000 km distant), providing a vivid overview of the dwarf.

Comments (0)