Earth, Mars and Venus all looked pretty similar when they first formed. Today, Mars is dry, cold, and dusty; Venus has a hot, crushing atmosphere. Why did these sibling planets turn out so different?

On Earth, clouds and rain are made of water. But the James Webb Space Telescope has found that on a planet called WASP-107b, the rain and clouds are made of sand.

Astronomers pointed the James Webb Space Telescope at a common kind of planet that's bigger than Earth but smaller than Neptune. What they saw wasn't what they expected.

These so-called exoplanets include rocky worlds similar in size to Earth, gas giants larger than Jupiter and even"'mini-Neptunes."

NASA's TESS telescope finds a small, iron-rich planet which could help explain the origins of Mercury, the innermost planet in our solar system

NASA's Juno spacecraft sweeps over Jupiter's Great Red Spot and makes a 3D map of the giant storm. The findings could shed light on gas giant exoplanets in distant solar systems.

NASA should work toward a new space telescope that could view small planets around distant stars with the potential to host life, expert panel says