Jupiter would be dwarfed by the new planet
by News Online Science Editor
Dr David Whitehouse
Wednesday, 13 October, 1999, 10:02 GMT 11:02 UK
A UK astronomer may have discovered a new and bizarre planet orbiting
the Sun, 1,000 times further away than the most distant known planet.
Currently, Pluto is the planet we think of being on the edge of our
planetary system. But the new body would be 30,000 times more distant from the Sun than
the Earth - putting it a significant distance on the way to the nearest
What is more, it seems that the new planet cannot be a true member of
our Sun's family of planets. It may be a planet that was born elsewhere,
and roamed throughout the galaxy only to be captured on the outskirts of
our own Solar System.
The controversial suggestion that there is another planet in deep space
comes from Dr John Murray, of the UK's Open University. For several
years, he has been studying the peculiar motions of so-called
Comets - flying mountains of rock and ice - are thought to come from the
cold and dark outer reaches of the Solar System, far beyond the planets
in a region called the Oort cloud. They spend millions of years in the
Oort cloud, until they are deflected
into an orbit that takes them into the inner Solar System where we can
By analyzing the orbits of 13 of these comets, Dr Murray has detected
the tell-tale signs of a single massive object that deflected all of
them into their current orbits.
"Although I have only
analyzed 13 comets in detail," he told BBC News
Online, "the effect is pretty conclusive. I have calculated that there
is only about a one in 1,700 chance that it is due to chance."
In a research paper to be published next week in the Monthly Notices of
the Royal Astronomical Society, he suggests that the so-far unseen
planet is several times bigger than the largest known planet in our
Solar System, Jupiter.
Being so far from the Sun - three thousand billion miles - it would take
almost six million years to orbit it.
"This would explain why it has not been found," explained Dr Murray to
BBC News Online. "It would be faint and moving very slowly."
He has calculated that it lies in the constellation of Delphinus (the
But the planet orbits our Sun in the "wrong" direction, counter to the
direction taken by all the other known planets.
It is this which has led to the remarkable suggestion that it did not
form in this region of space along with the Sun's other planets, and
could be a planet that "escaped" from another star.
But, if it is discovered, will Dr Murray get a chance to name it?
"Probably not," he says. "That will be up to an international committee.
But it would be nice to make a few suggestions."
Further evidence to support Dr Murray's claims will be presented at a
conference in Italy next week.
of the University of Louisiana at Lafayette, has
carried out a similar study and reached broadly similar conclusions. His
research is to be published in Icarus, the journal of Solar System