Tiny dustless asteroids around the Earth reveal a Big secret about solar storms

tech.hindustantimes.com:

Asteroids are strange. Some are made of rocks while others are made up of ice (Themis), sometimes they rotate and sometimes they just tumble (Toutatis) and they can be from tens of kilometers wide to as small as a few centimeters. And scientists have spent years trying to understand these anomalies in asteroids and the cause behind them because they just might reveal something important to us. And it appears that scientists have come across something like that. Smaller asteroids like Bennu and Ryugu share a very intriguing characteristic — they are all dustless. And scientists have found that this feature is caused by various solar activities including solar storms.

It might seem a little strange to think that a solar storm can make asteroids dustless and to understand its relevance for us, but rest assured, it does reveal information that can be useful to us. Scientists found out about this phenomenon very recently after spacecraft Hayabusa2 and OSIRIS-REx visited the two asteroids and saw that their surface is not smooth like the large asteroids like Vesta. The body of these smaller asteroids looked like a rocky canyon with small rocks dumped everywhere and not a speck of dust to bind them together.

A new study, published in the Nature journal, highlights that smaller asteroids lose the dust on the surface due to a process known as electrostatic repulsion. In simple words, electrostatic repulsion means two particles of the same charge repel each other. And the study has found that what causes this in the smaller asteroids is the ultraviolet radiation from the Sun. So, when these rays fall on the dust, the dust loses electrons from its atomic structure and once they get charged, they shoot off the asteroid and dive into