Planetologists explain how Charon's "red riding hood" was formed

Scientists from the Northwestern Research Institute used experiments, computer

modeling and data obtained by spacemission "New Horizons" to study Charon's atmosphere. The study showed that the rarefied methane atmosphere of the satellite is subject to explosive pulsations, and the polar red spot is formed under the influence of the solar wind.

"Little Red Riding Hood" at the North Pole of Charonfirst discovered the New Horizons ship in 2005. Previously, scientists had suggested that this hue was due to a material similar to tholins, which is formed when methane molecules break down under the influence of Lyman-alpha ultraviolet light from scattered hydrogen in the interstellar medium. In new papers published in Science Advances and Geophysical Research Letters, the researchers found a more complex process.

Planetologists have reproduced surface conditionsCharon in a laboratory experiment to measure the composition and color of hydrocarbons formed on the satellite. During the experiment, methane was condensed in an ultrahigh vacuum chamber under the influence of Lyman-alpha photons.

The study showed that methane is indeedbreaks up into remnants at Charon's north polar spot. But mostly ethane is formed, a colorless material that cannot give a reddish tint.

In addition, the researchers found thatThe atmosphere on Pluto's moon is subject to cyclic explosive events every planetary year (258 Earth years). The spring sunrise causes the polar methane, frozen during the centuries-old winter night, to return back to the atmosphere. At the same time, the density of the air shell increases sharply by almost 1000 times, and polar methane caps can suddenly move between north and south, evaporate, and then freeze again.

Unlike methane, ethane is less volatile and morestable, so it does not evaporate during the spring "explosion". Researchers believe that it is ethane, under the influence of ionizing radiation from the solar wind, that synthesizes increasingly complex, redder materials responsible for the unique albedo on this moon.

Cover image: Courtesy of NASA / Johns Hopkins APL / SwRI

Read more:

Quantum simulator showed the division of an electron into parts in one-dimensional space

Physicists have created an atomic laser that can work forever

Two planets found not far from Earth that are very similar to ours