Page 11 - BBC Focus - August 2017

DI S PA T C HE S FR O M T H E CU TT I N G ED GE

AUGUST 2017 EDITED BY JASON GOODYER

Artist’s impression
of Planet Ten

S PA CE
IS THERE A TENTH PLANET?

Astronomers in the US have inferred the existence of an unknown ‘planetary
mass object’ affecting the movements of space rocks in a distant asteroid belt

It seems the Solar System may be a little more crowded extends to a few hundred Astronomical Units (AU)
than we thought: a planet around the size of Mars could with one AU representing the distance between Earth
PHOTO: HEATHER ROPER/LPL mysterious mass, dubbed Planet Ten, that appears to be in roughly the same plane. However, Kuiper Belt Objects
and the Sun.
be hidden among its outer fringes.
The Earth and the other major planets all orbit the Sun
A team from the University of Arizona has discovered a
tugging at the orbits of a population of space rocks known
(KBOs) are far enough away from the gravitational
attraction of the gas giants to be tilted away from this
as the Kuiper Belt in the icy outskirts of the Solar System.
The Kuiper Belt lies beyond the orbit of Neptune and
plane, and are affected by interactions with one another.

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