Astronomy
The Role of Dark Matter in Seeding the First Galaxies
Quick fact
Dark matter's gravity acted as the seeds for the first galaxies; without its mass, the universe's matter would have been too spread out for galaxies to form within a billion years after the Big Bang.
Why this is interesting
Every galaxy we see today, including our own Milky Way, began as a tiny clump of invisible matter. How could something we can't see have shaped the entire universe so profoundly?