At the right point of the orbit and stellar cycle, the star’s chromosphere brightens.

An illustration of the hazy, pink-hued gassy giant GJ504b, which may be a massive planet or a brown dwarf orbiting a nearby ...

Astronomers have uncovered the chemical profile of a very pink planet, potentially solving a decade-old mystery about its ...

The "Pink Planet," formally known as GJ504b, was discovered in 2013 and is technically not a planet but rather a ...

Venus, Jupiter and Mercury are due to form a planet parade in June visible across the US. What to know, including the date and time and where to look.

The hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there ...

The rusty world is full of mysteries—and some of the solar system's most extreme geology. Learn more about Earth's smaller, colder neighbor.

Planet 9 would fall somewhere in between these categories. It could be what is known as a Super-Earth, a rocky planet larger than our own, or a sub-Neptune, a gaseous world less massive and slightly ...

Mercury is due to join Venus and Jupiter in the night sky for an uncommon celestial event commonly known as a planet parade. Here's how to catch it.