Apart from Pluto, which was demoted from a planet ... "It's really difficult to explain the solar system without Planet Nine but there's no way to be 100 per cent sure [it exists] until you ...

Here's what to know about the short life of what was, for a single human lifetime, the solar system's smallest planet. Pluto was discovered in 1930 by Clyde Tombaugh, an American astronomer at the ...

The controversy endures over Pluto's true status, but the solar system underdog continues to capture hearts across the globe. Clyde Tombaugh didn't set out to discover Pluto when he sent his ...

This phenomenon known as a "planet parade," will feature Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune all ...

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all ...

He searched for Planet X from 1905 until his death in 1916, without luck ... upon by spacecraft from Earth, Pluto remained the only one of the solar system’s major worlds that never received ...

Pluto was discovered 95 years ago on Feb. 18, and even though it was demoted nearly two decades ago, it remains a fascinating part of our solar system. "Pluto is a complex and mysterious world ...