Solar activity makes space junk crash to Earth faster

The growing debris field in Earth orbit may someday endanger our access to the stars. Today, that field consists of nearly 130 million pieces of space junk — dead satellites, old rocket bodies and tiny fragments generated by on-orbit collisions. Understanding how debris shifts in orbit can help to avoid disastrous collisions . And a new study increases that understanding, showing that space debris falls to Earth faster when the sun is more active. "For the first time, we find that, once solar activity passes a certain level, this loss of altitude happens noticeably more quickly," the study's corresponding author, Ayisha Ashruf, a scientist and engineer at Vikram Sarabhai Space Centre in Thiruvananthapuram, India, said in a statement . "This observation is expected to be key for planning sustainable space operations in the future," Ashruf added. All objects in Earth orbit lose altitude over time, slowly moving toward our atmosphere. While space stations and satellites compensate for this loss with engine burns to maintain their desired orbits, space junk falls naturally. In the new study, researchers measured the trajectories of 17 pieces of space junk in low Earth orbit over a 36-year span, starting two generations ago. "All of this information comes from objects launched back in the 1960s," Ashruf said. …