Scientists have known for 70 years that there is much more mass in galaxies than can be seen. For example, spiral galaxies rotate at speeds that are only possible if the total mass of the galaxy is ...

Astronomers have proposed a radical idea: dark matter—the mysterious substance making up most of the universe’s mass, might ...

For a long time, astronomers have noticed that stars rotate too quickly at the edges of galaxies, as if a hidden mass were preventing them from escaping. This observation raises a fundamental question ...

Here’s what you’ll learn when you read this story: For nearly a century, scientists have been searching for direct evidence of dark matter—one of the key missing pieces of our theoretical ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

Annie Murphy Paul is the author of the forthcoming book Brilliant: The New Science of Smart. Many of science’s most important breakthroughs, from the discovery of microorganisms to the theory of ...