Eris was discovered. It was considered the largest known dwarf planet in the solar system until a year later when Pluto was ...
The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a ...
Learn about the size, temperature, and colour of each planet, and discover why Pluto is no longer considered a planet.
Potentially habitable exoplanets are so incredibly common that astronomers have started to consider more unusual situations ...