Pluto

The official definition of a “planet” could be set to change again soon. Last time that happened, Pluto was kicked out of the club, but the new proposed definition is designed to be more inclusive.

The future of NASA's New Horizons interstellar probe as it speeds out of the solar system, never to return, is a bit more secure after the space agency announced a new extended mission plan that includes another possible Kuiper Belt object flyby.

A bizarre object named ‘Oumuamua, defying classification, was the first interstellar object ever discovered. Now a newly proposed origin story neatly explains all of its observed oddities – it may be a piece of nitrogen ice from an “exo-Pluto.”

Well over 100 new minor planets have been discovered in our solar system, in the darkness out beyond the orbit of Neptune. The discoveries were made by sifting through several years’ worth of data gathered by the Dark Energy Survey (DES).

Research has shed light on how Pluto’s heart-shaped plane of frozen nitrogen creates winds in the planet’s thin atmosphere, that lead to discolorations on its bright surface. The study used information collected by NASA’s New Horizons spacecraft.

As NASA scientists finalized their plans for the New Horizons mission in the mid 2000s, the US had already sent space probes to all of our neighboring planets between Mercury and Neptune. But dangling at very edge of the solar system was a dark and icy carrot named Pluto, the final item on a bucket list of planetary exploration.

In 2006, Pluto was downgraded from planet to dwarf planet – and now, based on the same definition an object in the asteroid belt may need to be upgraded from asteroid to dwarf planet. New observations of asteroid Hygiea suggest it fits the criteria.

Astronomers are welcoming the newest and most distant object in the solar system – a dwarf planet orbiting more than 100 times further from the Sun than Earth. And because its discoverers aren’t the most creative bunch, it’s been dubbed “Farout.”

There could be thousands of dwarf planets – Pluto-sized or smaller – lurking at the very edges of the Sun’s influence. Now, astronomers have spotted a new distant dwarf with an incredibly wide orbit, lending further evidence to the idea that a much bigger “Planet X” is out there somewhere.

Pluto was demoted from planet status to dwarf planet in 2006. But a new study suggests it should be resurrected as a planet, since the definition the object failed to meet was not based on precedents set in scientific literature.

​​NASA’s New Horizons spacecraft has successfully awoken from a planned 165-day hibernation period ahead of its historic flyby of the Kuiper Belt object Ultima Thule, which is set to take place on New Year’s Day 2019.

Almost three years after NASA's New Horizons deep space probe made its historic flyby of Pluto, the International Astronomical Union (IAU) has released the first list of official names for features on the face of the dwarf planet's largest moon, Charon.