The studies - both published in Icarus - look at something astronomers already knew: that Eris and Makemake, the second and fourth largest dwarf planets in our solar system, contain a lot of methane.

Quadruple Saturn Moon: On February 24, 2009, the Hubble Space Telescope took a photo of four moons of Saturn passing in front ...

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, ...

and — a few months after Eris — Makemake in March 2005, forcing the astronomical community’s hand. In August 2006, the International Astronomical Union (IAU) formally defined a “planet ...

An amateur astronomer discovered Pluto 95 years ago today. The former planet will complete an orbit in another 153 years.

Earth's Moon: NASA's Galileo spacecraft took this image of Earth's Moon on Dec. 7, 1992, on its way to explore the Jupiter system in 1995-97. The Moon is Earth's only natural satellite.