Physics
Probing Trans-Neptunian Object Atmospheres with Stellar Occultations
Quick fact
By timing a stellar occultation, astronomers can measure a trans-Neptunian object's diameter to within a few kilometers, even though it is billions of miles away—far more precisely than any telescope image can achieve.
Why this is interesting
Have you ever watched a distant streetlight blink out as a truck passes in front of it? Astronomers use that same principle to study worlds at the edge of our solar system.