The Boötes Void: A Hole in the Universe 330 Million Light-Years Wide
A region that should contain tens of thousands of galaxies holds barely 60. If the Milky Way sat at its center, we wouldn't have known other galaxies existed.
Cosmic Mysteries
'Oumuamua: The Interstellar Object That Accelerated on Its Way Out
The first visitor from another star system was shaped like nothing we'd seen, had no comet tail — and sped up as it left. Scientists still argue about it.
Something Invisible Is Pulling Our Entire Galaxy Toward It at 2 Million km/h
The Milky Way and thousands of neighboring galaxies are streaming toward a mysterious region called the Great Attractor — hidden behind our own galaxy's disk.
Something Is Sending Millisecond Radio Blasts From Across the Universe
Fast radio bursts release more energy in a millisecond than the Sun does in days — and some of them repeat on a schedule. We still don't know why.
85% of the Universe's Matter Is Missing — and We've Never Seen It
Every star, planet, and galaxy we can see is only a sliver of what exists. The rest is dark matter, and after 90 years we still don't know what it is.
The Wow! Signal: The 72-Second Radio Burst We've Never Heard Again
In 1977, a radio telescope in Ohio caught a signal so strange the astronomer on duty circled it and wrote 'Wow!'. Nearly 50 years later, it has never repeated.