Saturn, Venus, Neptune, Uranus, Jupiter, Mars and Mercury will be visible in an uncommon planetary alignment this month.

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto ...

Planet demographics reveal a puzzling lack of worlds in a certain size range throughout the galaxy F or centuries our solar system was the only planetary system known to humans. We had no proof other ...

Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

Pluto was once the ninth planet of our solar system, until scientists reclassified it in 2006, sparking outrage and debate.

NASA said the system is thought to be moving at least 1.2 million miler per hour, nearly twice as fast as our solar system.

For decades, we believed there were nine planets in our solar system—until Pluto was reclassified in 2006. But what if ...

The four planet-strong "planet parade" currently visible to the naked eye in the night sky for a short time after sunset will ...

To get somewhere in outer space, you can’t exactly drive in a straight line. Orbits are tricky things, and sending a probe to ...

Located around 858 light-years from Earth, WASP-121b has 1.2 times the mass of Jupiter but is puffed out, making it 1.9 times the width of the solar system's largest planet. It is so close to its ...

The eight major planets in our Solar System orbit the sun on the same flat plane but at vastly different speeds. Mercury, being the closest to the sun, completes an orbit in only 88 days ...