An international team of astronomers discovered a new dwarf planet this month, bringing the total number of objects that are “highly likely” to be minor planets in the solar system to 27.
The newly discovered dwarf planet, dubbed 2015 RR245, was spotted by the ongoing Outer Solar Systems Origins Survey (OSSOS) using the Canada-France-Hawaii telescope on Maunakea, Hawaii.
The OSSOS is tasked with mapping the massive number of objects made of ice and rock that comprise the enormous Kuiper Belt outside Neptune’s orbit, Dr. Michele Bannister of the University of Victoria wrote in a press release.
“The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the Sun. They let us piece together the history of our Solar System. But almost all of these icy worlds are painfully small and faint: it’s really exciting to find one that’s large and bright enough that we can study it in detail.”
In the year since NASA’s New Horizons spacecraft completed its flyby of Pluto, earthbound astronomers have catalogued some 600 Kuiper Belt objects, including 100 that might one day be classified as dwarf planets, Bannister told the New York Times.
“This is a big fish among a whole lot of small ones we’re working with.”
A dwarf planet is an object that orbits the sun and is large enough for gravity to have made it round, while a full size planet has cleared away the other objects in its orbit.
The newly discovered dwarf planet, 2015 RR245, orbits the sun every 700 years and has a size of about 700 km, one third that of Pluto, which used to be the solar system’s ninth planet until it was demoted a decade ago, Bannister told Yibada.
“I think it’s wonderful that Pluto has so much family, that it is part of a much bigger story.”
When the dwarf planet Eris, which is larger than Pluto, was discovered, it threw into question the designation of the solar system’s ninth planet. It was decided that Pluto was actually a dwarf planet and a Kuiper Belt object instead of a full-fledged planet.
Currently, the International Astronomical Union only recognizes five objects as dwarf planets: Pluto, Ceres, Haumea, Makemake, and Eris.
The only other celestial body big enough to be a dwarf planet is inside Neptune’s orbit and therefore not a Kuiper Belt object: Saturn’s 250-mile wide moon Mimas.
The new dwarf planet, 2015 RR245, was first spotted in February, and its existence was confirmed a few weeks ago. It’s impossible to directly measure the size of the dwarf planet because it’s so far from the sun, but scientists estimate it to be between 370 to 500 miles wide.
— Business Insider (@businessinsider) July 14, 2016
The OSSOS is tasked with mapping the orbital structure of the outer solar system in the hopes that such knowledge will help uncover information about the formation of the planets and our sun, Prof. Brett Gladman said in a press release.
“While not designed to efficiently detect dwarf planets, we’re delighted to have found one on such an interesting orbit.”
Michael Brown, a professor of planetary astronomy at the California Institute of Technology, discovered the dwarf planet Eris, which led to the demotion of Pluto as a full planet. Now, he spends his time tracking Kuiper Belt objects, and so far he’s found 96 that are larger than Saturn’s moon, Mimas.
This is how Jupiter 'shepherds' the asteroid belt, preventing asteroids from falling into the sun or hitting planets pic.twitter.com/nOIgLP0IVs
— Science GIFs (@Learn_Things) July 12, 2016
He and his colleague, Konstantin Batygin, were the first to theorize about the existence of Planet Nine, better known in popular culture as Planet X.
It’s this mysterious planet that could be responsible for driving a series of comets that usually hang out near Jupiter in toward the inner solar system and our home planet Earth.
If one of these rogue comets does come calling, there will be little that NASA can do to keep it from striking the planet and causing major damage to life on Earth.
[Photo via YouTube video screenshot]