Six Quick Facts About Our Solar System’s Newest Dwarf Planet
published during a waxing crescent moon.

Today, an international team of astronomers announced that they had discovered a new dwarf planet. Here’s what we know:

This is the clearest view we have of the new object, currently designated 2015 RR245:


Credit: OSSOS team

Look at it zip by on the right side the animation.

At an estimated to be 700 kilometers in size, it’s about half the size of Pluto.

Solar System’s Newest Dwarf Planet


The relative sizes of the other largest objects past the orbit of Neptune. Credit: NASA/JHUAPL/SwRI.

Its orbit is one of the largest seen for a dwarf planet — it takes 700 years to make one trip around the sun. 

Solar System’s Newest Dwarf Planet

Credit: Alex Parker/OSSOS team

At its furthest point in this highly elliptical orbit, it is 120 times further from the sun than Earth. At it’s closest point to the sun—which will happen around the tear 2096—it is 34 times the sun-Earth distance. The scientists estimate that the dwarf planet has been in this orbit for at least 100 million years.

It was found using the Canada-France-Hawaii Telescope on Maunakea, Hawaii

Solar System’s Newest Dwarf Planet

Credit: CFHT

Researchers were using the telescope as part of a project called the Outer Solar System Origins Survey (OSSOS), which is designed to map the structure of the deep outer solar system. Though the project has already identified over 500 objects past the orbit of Neptune, they were not actively looking for a dwarf planet, as this telescope is not designed for that kind of search.

It was first spotted in February of this year when researchers were looking at OSSOS images taken in September 2015.

Solar System’s Newest Dwarf Planet

Credit: CFHT

Based on the limitations of current technology, this may be the last large world past Neptune discovered until the 2020s, when bigger telescopes that can see dimmer objects become operational. 

Solar System’s Newest Dwarf Planet

Credit: NASA/JPL

A future telescope called the LSST might be able to do better, the scientists suggested.