A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is ...

Anyone who looked up at the sky on Wednesday night may have caught a glimpse of an impressive sight: all the planets of our solar system on display. The phenomenon — also known as a "planet ...

Pluto isn’t the only dwarf planet in our solar system's outer reaches. Now is an ideal time to look for the egg-shaped Haumea, says Abigail Beall ...

A star symbol marks the location of the host ... captured its first direct images of carbon dioxide in a planet outside the solar system in HR 8799, a multiplanet system 130 light-years away ...

Everyone knows about the Solar System, and the planets that make it up. They’re in space, orbiting the Sun, in an order we all at least used to be able to recite. But it was not always so.

NASA launched the Pioneer 11 mission into the outer solar system. Pioneer 11 would become the first spacecraft to fly by ...

"A star symbol marks the location of the host ... the rocky, Earth-sized planets of the TRAPPIST solar system.