Planet offers hope of finding similar solar system to our own

A JUPITER-LIKE planet 90 light years away has given astronomers their best hope yet of finding another solar system similar to our own, it was revealed yesterday.

The planet, about twice the mass of Jupiter, takes an almost circular path around its Sun-like parent star. It occupies a similar orbital position to Jupiter, 3.3 times further from its star as the Earth is from the Sun.

Dr Hugh Jones, from Liverpool John Moores University, who headed the British-led astronomers, said:

“This planet is going round in a nearly circular orbit three-fifths the size of our own Jupiter. This is the closest we have yet got to a real solar system-like planet, and advances our search for systems that are even more like our own,” he said.

The star, designated HD70642, is situated in the southern constellation Puppis and has properties very similar to those of the Sun.

British, Australian and US astronomers found the planet during a search for Sun-like solar systems.

It was discovered using the 3.9 metre Anglo-Australian telescope in New South Wales, Australia.

Like other extra-solar planets, it could not be seen directly but was detected using a high-precision technique which measures the degree to which a planetary body’s gravity causes its parent star to wobble in space.

About 100 planets have been found orbiting stars using this method. At present only huge planets as large or bigger than Jupiter can be detected.

But scientists believe if they look similar to our own gas giants their solar systems might also contain small rocky planets like the Earth.

However, the vast majority of planetary systems are nothing like ours.

Most of these large planets orbit much closer to their stars than Jupiter and Saturn do in our solar system. They also tend to have elliptical, rather than circular, orbits which would wreak gravitational havoc and make the existence of stable habitable worlds impossible.

Previously, only one other gas giant has been detected with a near-circular orbit beyond three Earth-Sun distances away from its star. This planet encircles the star 47 Ursa Majoris. But the same system contains another gas giant just two Earth-Sun distances from the star. Therefore, the 47 Ursa Majoris system is quite unlike ours.