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.

Astronomers have found more evidence of giant ice volcanoes on Pluto. New analysis of data and images gathered by the New Horizons mission have revealed unique surface structures that seem to have been produced by something known as cryovolcanism.

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.

NASA has commissioned Southwest Research Institute (SwRI) to study the feasibility of sending an orbital mission to Pluto. Its goal is to send an unmanned spacecraft to make a two-year study to the dwarf planet.

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.

If there is a subsurface sea on Pluto, why hasn't it frozen solid? According to computer simulations devised by researchers from Japan’s Hokkaido University and elsewhere, it may be that the hypothetical Plutonian sea may remain liquid thanks to an insulating gas layer keeping in the heat.

A team at the National Astronomical Observatory of Japan has discovered a new class of object that has long been thought to exist in the Kuiper belt on the fringes of the solar system.​ It's a small body on the scale of a few kilometers.

The New Horizons spacecraft is just a few weeks out from a historic flyby of the Kuiper Belt object, 2014 MU69 (Ultima Thule). After weeks of scans for any potential hazards, NASA has now given the all-clear to buzz the object on an optimal path, which will bring it in closer for a much better look.