Explained: NASA space telescope plunges to Earth after two decades studying cosmic explosions

NASA's Swift Observatory plunged to Earth on Wednesday, ending its 22-year mission studying the universe's biggest explosions.

gamma ray bursts

Extremely energetic explosions, often from dying stars, that Swift was designed to detect and study.

reentry

The process of a spacecraft falling back into Earth's atmosphere, often burning up partially or fully.

orbit-boosting

A maneuver to raise a satellite's orbit to prevent it from decaying and falling to Earth.

Space Force

The U.S. military branch that tracks objects in orbit, including monitoring Swift's reentry.

Swift Observatory

A NASA space telescope launched in 2004 to study gamma ray bursts and exploding stars.