A super-Earth planet that dips in and out of its star's habitable zone has been discovered just 19.7 light-years away. The planet, known as HD 20794d, gets farther out from its star than Mars is from ...

HD 20794 d completes its orbit just shy of two Earth years, placing it well within reach of conditions that might harbor life ...

"I'll always remember the first time I saw those iridescent clouds and was sure at first it was some color artifact." ...

Astronomers have discovered an exoplanet that might have favorable conditions for liquid water. This planet, HD 20794 d, belongs to the group known as super-Earths. It is located in a star system less ...

NASA's Perseverance rover has been busy gathering bits of Mars — rock cores the size of chalk sticks, clusters of broken fragments no bigger than pencil erasers, and even grains of dust fine enough to ...

While robotic missions have returned samples from the moon and space rocks like asteroids, a successful Mars mission would mark the first time that rocks from another planet made it back to Earth.