A giant comet in the distant reaches of our solar system has an
extremely large, elongated orbit that can't be explained by the
gravitational pull from the giant planets in their current positions.
... The supercomet, 2000 CR105, was first spotted in February 2000 and
is some 400 kilometers wide. It has a highly elliptical orbit well
beyond Neptune, the outermost giant planet in the solar system. ... New
observations by Brett Gladman of the Observatoire de la Côte d'Azur,
France, and his colleagues now reveal that 2000 CR105's orbit is much
larger and more distant than had been assumed: Even when it's closest to
the sun, at 6.6 billion kilometers, it lies far outside Neptune's orbit.
... The most exciting possibility is that a mid-sized planet at some 10
billion kilometers from the sun caused 2000 CR105's orbit. And because
such a planet would not be very vulnerable to orbit disruptions, it
could still be there, the team says.
