Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being classified as a dwarf planet. However, out beyond Neptune there could be ...

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...

Why is Pluto no longer a planet? Discover the real reason behind Pluto’s reclassification as a dwarf planet and the science that led to this change.

Each planet in our solar system is given a unique, humorous catchphrase that reflects its personality and role. From ...

For the first time, astronomers have imaged dozens of belts around nearby stars where comets and tiny pebbles within them are ...

Most of the information we have about planets beyond our solar system (exoplanets ... looked at a range of wavelengths of light, including in the optical region where effects of stellar ...

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to ...

All of our solar system’s planets are lining up to ... apparent than during a planetary alignment. An alignment including all of the planets except Mercury is taking place in mid-January.

The organic ingredients to life, hints to where Earth’s water came from, and the fundamental building blocks of our planet ...