Learning English - Words in the News
16 August, 2006 - Published 13:33 GMT
Planets plan increases total to 12
The International Astronomical Union has published its definition of a Planet. Under this definition Pluto will be a Planet as will its "moon" Charon and two others UB313 And Ceres. This report by Pallab Ghosh.
Critics of Pluto say that it’s little more than one of the larger icy lumps of rock that orbit at the fringes of our solar system and they argued that it should be stripped of its planetary status.
The debate took a new twist earlier this year when astronomers calculated that another far flung object called UB313 was slightly larger than Pluto so should that be called a planet too?
Now, after years of deliberation, a committee of astronomers have come up with a scientific definition of a planet. They say that it’s something that's round (because of its gravity) and orbits the Sun. If approved, this'll mean that Pluto keeps its planetary status. But it’ll also mean that its large moon Charon is also upgraded to planetary status as are UB313 and an erstwhile planetoid called Ceres.
That takes the total number of planets in our solar system to 12. With better telescopes that's likely to rise yet further as more worlds are discovered in the future.
Pallab Ghosh, BBC
at the fringes of
far flung object
orbits the Sun