Choose a topic and level, then practice at your own pace.
How telescopes have grown from simple glass lenses into giant space observatories that reveal distant galaxies.
Why scientists believe Mars may once have supported life and how robot rovers search for evidence today.
An explanation of how black holes form, how scientists observe them, and why time behaves strangely near them.
A talk about why telescopes are sent into space and what Hubble and Webb have revealed.
An explanation of what black holes are and how scientists study them.
The long training and hard work needed to become an astronaut.
A description of why astronomers build giant telescopes in remote, high places.
An account of robotic missions that look for signs of past life on Mars.
A report on serious plans to build a permanent base on the Moon and the challenges involved.
An introduction to the James Webb Space Telescope, how it works, and what it has discovered.
An astronaut describes her morning routine while living and working aboard the International Space Station.
Astronomers announce a new image of a black hole and explain what it teaches us.
Families gather on a dark hill at night to watch a bright comet cross the sky.