What makes a planet a planet? And what makes a star a star? Once we know this these defining characteristics, we start to ...

Wide-orbit planets are fairly common according to the study, and there's a good chance we have one of our own.

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly ...

When the Sun expands into a red giant, it will swallow the inner solar system and raise the temperature in the outer regions.

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

Using the James Webb Space Telescope (JWST), astronomers have peered deep into one of the Milky Way's most radiation-intense ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be fair—but one of the largest yet discovered and with an orbit around the Sun that ...

Researchers believe that 2017 OF201s highly eccentric orbit points to a chaotic origin, possibly caused by a gravitational ...

A composite image comparing the relative sizes of our solar system's known dwarf planets, including the newly discovered 2017 OF201. | Credit: Sihao Cheng et al. Scientists have found evidence of ...

On May 21, the International Astronomical Union’s Minor Planet Center announced the ... the most distant region in our solar system, which is home to many comets, and then sent back,” Cheng ...