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

To understand what happened to Pluto, we must actually go back to the late 1700's, when a number of astronomers thought that there was something odd to the spacing of the planets orbiting the Sun.

Planetary alignment is when several planets gather closely on one side of the sun simultaneously ... of times throughout the ...

Four planets will be in the parade in January, while seven will align in February. Here's how to see the events.

Christy had been imaging Pluto with the USNO's 1.5-meter (4.9-foot) telescope. Because Pluto is so far from the sun — more than ... covered in smoother plains, including one called Vulcan ...

The planets have something in store this winter: On January 21, the sun will meet up with Pluto for the first time in our lifetime. And it is bound to be big. Big as in you might feel it on a ...

Of the five dwarf planets in the Solar System – including ... Pluto is easily the best-known due to its brief categorization as a regular planet. Long before it could even make one turn around ...

In the earliest days, the Sun and the ... of having nine planets, which came about in the 1960s and lasted only until 2006, was a blip on the screen. And if you are still a Pluto-is-a-planet ...

Everyone knows about the Solar System, and the planets that make it up. They’re in space, orbiting the Sun, in an order we all at ... turned the planets, including Mercury, into worlds.

Pluto is 40 times further from the sun than Earth, with sunlight taking around 5.5 hours to reach it. It receives just 1/1,600th of the sunlight that Earth gets and temperatures can dip to -400F ...