An icy planet with a staggering 20,000-year orbit has been discovered passing through our solar system leading to the re-emergence of theories touting the existence of the fabled and mystical Planet 9. L91, as the icy rock is called, is an enigma defying previously established gravitational patterns.
Its discovery has added to mounting evidence that there are gravitational disruptions going on beyond what we can see, according to scientists working on the Outer Solar System Origins Survey.
Although L91 orbits our solar system’s sun, it never comes closer than 50 astronomical units and at its farthest extreme it is a whopping 1,430 AU away. This means it has a more elongated orbit than Sedna. Sedna is a distant Pluto-sized object, whose closest approach is 76 AU and whose estimated far point reaches 937 AU.
At present, scientists still can’t determine L91’s size, and have conflicting views on what is disrupting its orbit. Researchers suggest L91 was shunted out so far by Neptune but was dragged back into a more elliptical orbit by the gravity of a passing star or the Milky Way’s gravity.
Others, however, suggest an unseen ninth planet out beyond Pluto could be the answer. L91 was first discovered back in 2013 but the latest observations of its odd orbit suggest it is being pulled by a huge mass far beyond the sun and the solar systems gas giants.
The discovery of L91 comes amid a whole series of recent scientific revelations about space – from our plans to colonize Mars in the near future, to the discovery of Earth-like and potentially habitable planets within our galactic reach.
Michele Bannister, an astrophysicist at Queen’s University, Belfast, introduced L91 to the world at the American Astronomical Society’s Division for Planetary Science meeting held there on Monday.