Smallest planet so far found
2008-04-09 21:17
Madrid - The smallest planet
discovered outside our solar system has been found by Spanish
scientists.
"I think we are very close, just a few years away, from
detecting a planet like Earth," team leader Ignasi Ribas told a
news conference on Wednesday.
The rocky planet, with a radius about 50% greater
than the Earth's, circles a small red dwarf star 30 light years
away in the constellation of Leo, said the scientists from
Spain's Higher Council for Scientific Investigations (CSIC).
The planet, known as GJ 436c, was found by analysing
distortions in the orbit of another, larger planet around the
star GJ 436, a technique similar to that used more than 100
years ago to discover Neptune.
Worlds more like our own
With a mass about five times greater than Earth's, it is the
smallest planet yet discovered outside the solar system and
improving techniques are opening the way to discovering worlds
ever more like our own.
"In a very short time, we are going to be able to see a
planet with the same mass as the Earth, although it's going to
be in an orbit much closer to its star than that of the Earth
around the sun, so it won't strictly be a planet like the
Earth," said Ribas.
"Planets with a mass similar to Earth situated at a distance
from their star which allows liquid water on the surface, in
other words, a habitable planet, we're probably a bit further
from (discovering those), but we surely will in a decade."
Scientists are increasingly finding small
rocky worlds as they realise that planetary systems are
extremely common in stars around our galaxy.
GJ 436 is not much bigger than the Earth and it orbits close
to its small, relatively cool star once every five Earth days.