Astronomy

New simulations suggest that a 9-mile-thick layer of solid diamonds may lurk deep below the surface of Mercury. The gems almost certainly can't be mined for bling — but they may help solve some of the planet's biggest mysteries.

Citizen scientists have discovered what may be a brown dwarf racing through the cosmos at around 1.2 million miles per hour. Now astronomers want to know what launched it.

Vivid clouds swirl across Jupiter's skies like colorful brushstrokes in a new photo from NASA's Juno spacecraft.

A peculiar leopard-spotted rock, found beside an ancient, dried-out river in Mars' Jezero crater, contains some tantalizing clues of ancient life, NASA said.

With its moonless sky, the first week of August is one of the best times all year to see the Milky Way and meteor showers without a telescope. Here's how to be in the right place at the right time for the best view.

The Hubble Space Telescope zooms in on a dense ball of millions of stars within a galaxy orbiting the Milky Way. Its ancient origins raise big questions about how galaxies form and grow.

Scientists have found a mysterious signal in the brightest gamma ray burst ever detected, and now they know what caused it.

A potential intermediate-mass black hole is hiding right next to our galaxy's supermassive black hole.

As Earth's orbit intersects with those of two comets this month, stargazers will have a chance to view spectacular double meteor showers.