STEM Challenges

How do astronomers measure the distance to a galaxy billions of light-years away? No single method works at all scales. Discover the clever series of ...

The solar system is almost entirely empty space. Distances between planets are so enormous that even our fastest spacecraft take years to reach them. ...

The solar system, nearby stars, and distant galaxies require completely different measuring sticks. Discover the astronomical unit, the light-year, an...

Every time you look at the night sky, you are looking into the past. Light takes time to travel across space, and the most distant galaxies we can see...

Visible light is only a tiny slice of all the radiation in the universe. Explore the full electromagnetic spectrum and discover how telescopes that se...

Despite the advantages of space, the world's best ground-based observatories are scientific powerhouses in their own right. Explore the giant telescop...