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

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

A planet roughly the size of Neptune has stunned astronomers by orbiting its star in the opposite direction of the star’s ...

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.

NASA’s Transiting Exoplanet Survey Satellite (TESS) has been used to discover Earth-size planet TOI 700 e. It is "orbiting ...

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.

Earth, our home planet, is a world unlike any other. The third planet from the sun, Earth is the only place in the known universe confirmed to host life. With a radius of 3,959 miles, Earth is the ...

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 ...