Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about ...

Earth has four seasons, but do other planets in our solar system also have hot summer days and cold winter nights?

This is probably the most convincing evidence for Planet Nine so far. It is believed that this planet is five to ten times ...

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

A breathtaking new video compresses more than a decade of deep-space observation into a few seconds, revealing the hypnotic ...

An international team from Taiwan, Japan, and Australia used 40 years' worth of data from two space probes to track down what ...

At the center is the sun, a yellow dwarf star ... from the eight major planets to dwarf planets, comets, asteroids, and icy objects — revolves around it. The solar system also includes the ...

Plato, the European Space Agency's terrestrial planet hunter spacecraft, is seen after having 24 of its 26 cameras installed.

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

A planet circling at a sharp 90-degree angle to the orbits of its two host stars has now been confirmed. This discovery ...

The Daniel K. Inouye Solar Telescope in Hawai'i captured an image of a sunspot larger than several planets using a new ...