Astronomers have only gone and found a new planet in our solar system

You'd think it would be pretty hard to hide a planet. 

They tend to be... well, you know, planet-sized. Even dwarfplanets are massive - and yet it's taken all this time for a group of astronomers to identify 2015 RR245, the latest member of our solar system.

Sure, 2015 RR245 is only a dwarfplanet: it sits roughly 120 times Earth's distance from the Sun, but due to its distance, astronomers aren't sure if it's, "either small and shiny, or large and dull", estimating that it could have a diameter of around 700km. Its elliptical orbit takes about 700 years to complete, and looks something like this...

Discovered as part of the Outer Solar System Origins Survey using the Canada-France-Hawaii Telescope on Maunakea, Hawaii, it's hoped that closer observation of this little chap will help astronomers come to understand how our belt of planets came into being.

"Finding a new dwarf planet beyond Neptune sheds light on the early phases of planet formation,” said Brett Gladman, the Canada Research Chair in planetary astronomy at the University of British Columbia. “Since most of these icy worlds are incredibly small and faint, it’s exciting to find a bright one that is easier to study, and which is on an interesting orbit."

It's hoped that the Outer Solar System Origins Survey could confirm the existence of around another 100 dwarfplanets neighbouring 2015 RR245. Turns out it's actually really hard to spot a planet when they're a bit small and millions of miles away. Keep up the good work guys. 

(Image: Canada-France-Hawaii Telescope)