References

The Event Horizon Telescope produced the first-ever image of a black hole.

The space shuttle Challenger was one of NASA's greatest triumphs and also its darkest tragedy.

The solar system has a sense of humor: A decade from now, on Friday, April 13, 2029, a large asteroid will streak across the sky — but it's a cause for excitement, not fear, scientists say.

Beyond Neptune, the Kuiper Belt is a vast region of icy objects called Kupier Belt Objects (KBOs), including dwarf planets Pluto, Eris, Maumea and Makemake — and possibly a true ninth planet.

Fire, ice, volcano or star — planets have a variety of ways to die.

How time is coordinated around the world.

What's the matter with antimatter?

A look at some of the records people have set during spaceflight.

This impressive cloud of cosmic gas and dust is an ancient star nursery.

Going to the moon is hard, and Israeli nonprofit SpaceIL is one of a handful of organizations that knows exactly how hard.

In 1783, the Montgolfier brothers' plan to reach the sky was full of hot air.

Sorry, Pluto. Not everyone can be a planet.

To this day, the photos taken by the Soviet spacecraft are the best we have from the cloudy planet.

The aviation giant aims to take astronauts to the International Space Station in a capsule that is similar to Apollo spacecraft.

Arcturus is a red giant that is one of the brightest stars in Earth's night sky.

Rigel is the brightest star in Orion, and will eventually explode into a supernova, most astronomers say.

The CHIME radio telescope aims to explain two poorly understood cosmic phenomena, one dating back to the early universe and one taking place today.

IBEX is helping astronomers figure out where the edge of our solar system ends and the rest of space begins.

All we know is that this mysterious object came from somewhere very far away.