Astronomy
When the Earth Had Two Moons
A new model—“The Big Splat”—explains the strange asymmetry of the moon.
Looking for a Second Earth in the Shadows
Scientists are blocking out the light of distant suns to look for life.
Falling in Love With the Dark
One astronomer has taken to U.S. National Parks to rekindle an old romance.
The Billion-Dollar Telescope Race
How three groups are competing to make the first extremely large telescope.
The Stories That Galaxies Tell
Peculiar shapes were the key to realizing that galaxies merge.
How to Map a Galaxy When You’re Right in the Middle of It
Why the Milky Way looks like it spirals.

