Skip to main content

Space Ed

Dark matter: How does it explain a star's speed? - Don Lincoln

101,117 Views

0 Questions Answered

Let’s Begin…

All the stars in a spiral galaxy rotate around a center -- but to astronomers, the speed that each star travels wasn't making sense. Why didn't stars slow down toward the edges as expected? Don Lincoln explains how a mysterious force called dark matter is (possibly) the answer -- and why the search for an answer matters.

Previous
Which is not true about dark matter?
Next

About Space Ed

Space Ed helps you untangle the mysteries of space with the universe’s best videos on everything from Einstein's theory of relativity to what it would take to live on Mars. Brush up on the science, philosophy and mystery of space, because the fabric of the universe is the same fabric that connects us all.

Meet The Creators

  • Narrator Don Lincoln
  • Director Gatze Zonneveld
Certificate of Achievement

Earn a certificate

Get a certificate for completing any 30 lessons. Here's how:

  1. Make sure you are signed into your Space Ed account. Register if you don't already have an account.
  2. To complete a lesson, WATCH the video and finish all the questions in the THINK section.
  3. Complete any 30 lessons - you'll get a green checkmark on each lesson you complete.

That's it! You will get your certificate in an email.