Astrophysicists have once again enriched our knowledge of the cosmos with a new discovery: two small planets orbiting ...

LTT 9779 b, an ultra-hot Neptune, is defying expectations. With temperatures soaring to nearly 2,000°C and a tidally locked ...

Seven planets are on display in the night sky at the end of February, but some will be harder to spot than others. Here’s what you need to know to catch a glimpse.

Neptune sets around 8:25 p.m. and Venus sets ... The new definition requires that a planet: orbit the sun is large enough to be round has cleared its orbit of other small bodies.

Mercury, the closest planet to the Sun, completes an orbit – a year for the planet – in 88 days. Earth's year, of course, is 365 days, while at the upper end, Neptune takes a whopping 60,190 ...

According to NASA, multi-planet lineups are visible "every few years," but a seven-planet alignment is particularly uncommon, as each planet's orbit varies, with some moving more quickly and Mercury, ...

The planet Neptune wobbled in its orbit around the Sun. That could only mean one thing, astronomers said: There was a ninth planet out there, somewhere, lurking in the fringes of the solar system.

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary ...

Neptune sets around 8:25 p.m. and Venus sets ... "A dwarf planet is an object in orbit around the Sun that is large enough to pull itself into a nearly round shape but has not been able to clear ...