Here's how lunar dust clouds are formed, say scientists

Scientists have now identified a mechanism explaining the appearance of two dusty plasma clouds (lunar dust) resulting from a meteoroid that impacted the surface of the Moon.

The study, conducted by physicists from the Higher School of Economics and Space Research Institute, was published in JETP Letters.

The collision of a meteoroid with the surface of the Moon greatly changes the properties of the surrounding dusty plasma system by throwing a large quantity of lunar debris, that are dust particles measuring 10-100 microns, into the exosphere.

In 2015, astronomers at the Garden Observatory in Gordola (Switzerland) observed a similar phenomenon when they recorded an optical flash resulting from a meteoroid impacting the Moon.

 

An international group of scientists using data from astronomical observations concluded had then concluded that a fairly large and fast-moving meteoroid had impacted the Moon, raising two clouds of unknown composition.

Researchers determined that a meteoroid's collision with the surface of the Moon produces a shock wave that throws up regolith fragments and droplets of molten material into the surrounding free space.

Those fragments and hardened molten droplets rise above the surface of the Moon, interact with the electrons in the solar wind and solar radiation and take on an electrical charge. Two dusty plasma clouds form as a result -- one composed of regolith fragments and a second of hardened droplets of molten material. The differing characteristics of the two clouds make it possible to observe them separately.

Scientists found that a cloud formed by hardened droplets of molten material expands significantly faster than a cloud formed by regolith fragments.

According to co-author of the study Sergey Popel, lunar dust is a significant risk factor for spacecraft, equipment, and the astronauts' health. He added that equipment covered with dust can malfunction. Furthermore, astronauts carry dust on their spacesuits into the lunar module where it becomes suspended weightlessly in the air, causing them to inhale the particles during their entire return trip to Earth.

Therefore, understanding the mechanism by which dusty plasma clouds are formed is important for ensuring the safety of space flights to the Moon, he added.