Heavier than Jupiter, but lighter than a small star, brown dwarfs are difficult to distinguish from giant planets. For years, astronomers have searched for a yardstick that can separate the giant ...

We have all been taught in school that planets revolve in the same direction as the Earth, i.e., in the counterclockwise direction. However, the universe never ceases to amaze us with its unexpected ...

Astronomers using NASA’s Hubble Space Telescope have measured the rotation rate of an extreme exoplanet by observing the varied brightness in its atmosphere. This is the first measurement of the ...

Editor’s note: Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Mars is rotating more quickly than it ...

Using new data from NASA’s Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the length of a day on Saturn. It’s 10 hours, 33 minutes and 38 ...

Astronomers discover that the rotation speeds of distant planets reveal how they form and evolve in the universe ...

Earth is the planet we have the best opportunity to understand in detail—helping us see how other rocky planets behave, even ...