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

Try stargazing. Need a new idea to keep kids entertained? Try stargazing. Free learning activities and videos about the solar system Free learning activities and videos about the solar system Free ...

Worlds will align for a "planetary parade" in January, with four bright and easily visible to the naked eye. But an even ...

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

With a radius of 2,106 miles, Mars is the seventh largest planet in our solar system and about half the diameter of Earth. Its surface gravity is 37.5 percent of Earth’s. Mars rotates on its ...