Astronomy
The Mystery of the Missing Baryons in the Local Universe
Quick fact
Recent observations using X-ray and microwave telescopes suggest the 'missing' baryons are hiding in vast filaments of hot gas between galaxies, finally accounting for the deficit.
Why this is interesting
You're made of matter—the same stuff that makes up stars and planets. But when astronomers count all the 'ordinary' matter in the nearby universe, half of it seems to have vanished. Where did it go?