A penny—sized neutron star would weigh about a billion tons on Earth!!
Neutrons are remnants of supernovae whose protons & electrons literally fused into neutrons because of immense gravity.
2. Galaxies Collide Without Even Touching
When galaxies collide, the stars are soooo far apart they almost never actually crash into each other.
Instead, their gravitational forces just reshape each other, making new shapes like rings and tidal tails.
3. There’s a Supermassive Black Hole at the Center of Every Galaxy
Most galaxies, including our Milky Way, have a supermassive black hole at their core, millions to billions of times more massive than the Sun.
These black holes are key to the formation of galaxies, BUT WE DON’T EVEN KNOW WHAT BLACK HOLES ARE MADE OF.
4. Dark Matter Makes Up Most of the Universe
About 85% of the matter in the universe is dark matter, which doesn’t emit light and is invisible, but we know it’s there because of its gravitational effects.
It’s one of the biggest mysteries in modern astrophysics.
5. Quasars are the Brightest Things in the Universe
Quasars can outshine entire galaxies and are visible billions of light-years away (powered by supermassive black holes, duh).
They are incredibly distant and provide a glimpse into the early universe.
6. Pulsars Spin Faaaaaast
Pulsars are rapidly spinning neutron stars that emit beams of radiation. The fastest known pulsar rotates 716 times per second.
These cosmic lighthouses help scientists study extreme states of matter.
Larger galaxies often grow by merging with and absorbing smaller ones, a process known as galactic cannibalism.
The Milky Way has consumed several smaller galaxies in its history.
8. The Universe is Expanding Faster Than the Speed of Light
While nothing can travel through space faster than light, the fabric of space itself can expand faster, causing galaxies to move away from us at superluminal speeds.
This expansion is driven by dark matter (because of course).
