Do Aliens & UFOs exist? Has man been visited by other races from other worlds? Explore the fascinating evidence for and against the existence of extraterrestrials.

Is the U.S. Government Hiding New Proof of Alien Life?

Could Dark Matter Spawn 'Shadow Life'?

What We Do — and Don't — Know About the Pentagon's Secret UFO Program

Astronomy is a broad discipline covering all facets of astrophysics. In this section you can learn about the origins of the universe, black holes and other astronomical phenomena.

The Great Red Spot May Expose Jupiter's Watery Secret

Heads Up Stargazers! Two Comets Passing Close to Earth in September

The Perseid Meteor Shower Is Back — Here's What You Need to Know

What is the future of space travel? Explore the technologies we’ll use to visit the stars in the near and not-so-near future, from space planes to robonauts.

Russia Sending Humanoid FEDOR Robot into Space

Why Did NASA Just Send a Load of Sperm Into Orbit?

Chinese Insects and Plants Will Be the Next Earthlings on the Moon

Spaceflight covers topics related to human presence in outer space. Learn about weightlessness, astronauts and space tourism in this section.

10 Surprising Facts About Astronaut Training

Point Nemo: Where Spacecraft Go to Die

Why Fruit Flies Were the First Animals in Space

Space exploration is a broad topic covering many facets of deep-space and planetary science. Learn about space probes, Mars Rovers, SETI and other out-of-this-world subjects.

Mysterious Fast Radio Bursts Are Starting to Pile Up

Tiny Satellite to Search Universe for Missing Matter

How Close Can We Get to the Sun?

Space Transportation Systems (STS) are the systems and architectures that deliver payloads and humans to outer space. Learn about space shuttles, rockets and other spacecraft.

Can We Get Into Space Without Big Rockets?

3-D Printing Your Own Tractor Beam Levitation Device

Elon Musk Wants You to Go to Mars for Just $200,000