When was Pluto discovered? Pluto was discovered in 1930 by Clyde Tombaugh, an American astronomer at the Lowell Observatory ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Asteroids are rocky objects that orbit the Sun, just like planets do. There are millions of asteroids of very different shapes and sizes. Some are almost spheres, like planets, but most are ...

Astronomers have discovered an Earth-size planet that is showered with so much radiation, its atmosphere eroded away long ago ...

Venus is often called Earth's "sister planet" because it is similar in size and composition. However, it is covered in volcanoes and lava flows, indicating ongoing volcanic activity. The Venusian ...

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.