The four exoplanets orbit Barnard’s Star so closely that their years last only a few Earth days. They are probably rocky and, ...

Astronomers have revealed new evidence that there are not just one but four tiny planets circling around Barnard's Star, the second-nearest star system to Earth.

(Earth, of course, is the eighth planet, and poor Pluto was demoted in 2006 and is now considered a dwarf planet.) Mars, Venus, Jupiter, Mercury and Saturn should be visible to the naked eye.

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, ...

Pluto was discovered at Lowell Observatory in Flagstaff, Arizona in 1930 and was considered our ninth planet until 2006. The International Astronomical Union reclassified Pluto as a dwarf planet ...

After tracking a puzzling X-ray signal from a dying star for decades, astronomers may have finally explained its source: The ...

Shields stressed that this results in a much faster rotation period—10 hours—for the white dwarf exoplanet, while Kepler-62's exoplanet has a 155-day rotation period. While both planets would ...