Pluto's crater-less surface indicates the presence of geological processes that have erased the marks left by asteroids and comets.
After a nine-year expedition, the New Horizon spacecraft finally reached Pluto to see what's at the heart of the exoplanet.
Astronomers made a big discovery in determining Pluto's dwarf planet credentials.
Pluto was demoted to dwarf planet status, but it still has moons. This new moon, called P5 for now, is the fifth moon found orbiting Pluto.
If recent research is correct, the blackness between stars harbors more excitement than you could possibly comprehend.
So, if the planet doesn't orbit a sun, can it still be called a planet?
On last count, there were nine planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Soon, however, we might need to add a tenth planet to the solar lineup. Learn more on this Moment of Science.
Learn about the most distant object to orbit the sun, on this Moment of Science.
It may sound sci-fi, but the Termination Shock is one of two proposed boundaries to our solar system. Learn about the final frontier on this Moment of Science.
Have astronomers discovered a new planet? Find out on this Moment of Science.