An animation posted to Twitter has shocked social media users by showing the impressive size of Jupiter and just how rapidly the solar system's largest planet rotates. The animation posted by ...

A new study provides the most accurate estimate of the frequency that planets that are similar to Earth in size and in distance from their host star occur around stars similar to our Sun. A new study ...

Astronomers studying extreme planetary systems have identified worlds so massive that they rival the smallest stars in size.

Astronomers have discovered a planet the size of Jupiter orbiting a star that’s only half the size of the sun — a celestial phenomenon that contradicts theories of planet formation. NGTS-1b, a massive ...

Want to know how the Millennium Falcon compares in size to an Imperial Star Destroyer? Just watch a Star Wars movie. But if you want to know how that hunk of junk compares to the Battlestar Galactica, ...

In The Little Prince, the classic novella by Antoine de Saint-Exupéry, the titular prince lives on a house-sized asteroid so small that he can watch the sunset any time of day by moving his chair a ...

Astronomers have detected what may be four roughly Earth-size planets orbiting Tau Ceti, the nearest sun-like star. Two of the worlds appear to orbit within Tau Ceti's habitable zone, though a cloud ...

This story was updated at 1:55 p.m. EST. The Milky Way hosts at least 17 billion Earth-size alien planets, and probably many more, a new study reveals. Astronomers have determined that about 17 ...

Mercury is the innermost and smallest of the eight major planets in our Solar System, orbiting closest to the Sun. Though ...

A new study provides the most accurate estimate of the frequency that planets that are similar to Earth in size and in distance from their host star occur around stars similar to our Sun. Knowing the ...