Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto turns out to have as much complexity as Mars or Earth, so much so that I ...

The relative quantities of volatile gases like methane and ethane can reveal key details about distant Kuiper Belt objects.

is measured on a scale of 0 to 1, with 0 being perfectly circular and 1 being extremely stretched. Pluto, for example, has a highly elongated orbit compared to the planets in our solar system and ...

Viewed in this longer context, the previously modern idea of having nine planets, which came about in the 1960s and lasted only until 2006, was a blip on the screen. And if you are still a Pluto ...

Thomas says this goes for all outer planets: Jupiter, Uranus, Neptune and Pluto. “Jupiter and Saturn are the only outer planets that the ancients were aware of in previous times,” explains Thomas.

This size ratio makes the Pluto-Charon system a rarity, often referred to as a binary planet system. Unlike Earth, where the Moon orbits the planet, Pluto and Charon orbit each other, forming a ...

Elongation is the angle, in degrees, between the Sun and the planet as seen from here on the Earth. Superior planets (those that lie further from the Sun than us: Mars, Jupiter, Saturn, Uranus, ...