The ringed gas giant Saturn has officially replaced Jupiter as the planet in our solar system with the most moons. The ...

Neptune, Pluto. Pluto was last and least of them. An icy dwarf only half the size of the United States, it was on average 3.7 billion miles from the sun. It also has a decidedly strange orbit that ...

Pluto, with its heart-shaped glacier ... for wobbles that astronomers had observed in the orbits of Uranus and Neptune. He searched for Planet X from 1905 until his death in 1916, without luck.

For decades, it captivated imaginations with its icy surface and distant orbit beyond Neptune. But in 2006, Pluto’s planetary reign came to an end when the International Astronomical Union ...

of [Uranus and Neptune]." Breaking space news, the latest updates on rocket launches, skywatching events and more! He called this hypothetical world "Planet X." "In some ways, Pluto's more of a ...

Pluto never really fit in with the other planets in the solar system. Its orbit was out of plane with the other planets. From 1979 to 1999, it was closer to the sun than Neptune. When other bodies ...

Pluto will mark a birthday of sorts on March 23 ... reckoning that it accounted for wobbles that astronomers had observed in the orbits of Uranus and Neptune. He searched for Planet X from 1905 until ...

The cosmos is filled with wonders yet to be discovered. One of the latest mysteries captivating scientists and space ...