- body -
 |
) They reach Earth's vicinity in the inner solar system when their usual, remote orbits are disturbed. Dr Murray notes that the comets reaching the inner solar system include a group coming from directions in space that are strung out along an arc across the sky. He argues that this could mark the wake of some large body moving through space in the outer part of the Oort cloud, giving gravitational kicks to comets as it goes. The object would have to be at least as massive as Jupiter but currently favoured theories of how the solar system formed cannot easily explain the presence of a large planet so far from the Sun. If it were ten times more massive than Jupiter, it would be more akin to a brown dwarf (the coolest kind of stellar object) than a planet, brighter, and more likely to have been detected already. |
 |
Only when near to the Sun do these icy objects grow the coma and tails that give them the familiar form of a comet. Dr Murray notes that the comets reaching the inner solar system include a group coming from directions in space that are strung out along an arc across the sky. He argues that this could mark the wake of some large body moving through space in the outer part of the Oort cloud, giving gravitational kicks to comets as it goes. The object would have to be at least as massive as Jupiter to create a gravitational disturbance large enough to give rise to the observed effect, but currently favoured theories of how the solar system formed cannot easily explain the presence of a large planet so far from the Sun. If it were ten times more massive than Jupiter, it would be more akin to a brown dwarf (the coolest kind of stellar object) than a planet, brighter, and more likely to have been detected already. |
 |
. 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 star. 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. |
. 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 star. 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.
 |
also look at: http://www.peabody.jhu.edu/