WELLINGTON An international team of scientists has discovered an Earth-size planet in the middle of the Milky Way believed to have the potential to support life, a New Zealand member of the group said on Tuesday. It has a probable mass range between that of the Earth and that of the planet Neptune. Probably it would be a little bit heavier than the Earth, researcher Ian Bond said.

Auckland University fellow Bond said by telephone from the Mount John Observatory in New Zealand's South Island that the planet was the right distance from the nearest star to sustain life. It will be something like between one to four astronomical units, which places it in a promising region, he said. An astronomical unit is calculated to be the mean distance between the center of the Earth and the center of the sun.

A team of New Zealand and Japanese astronomers, working with Australian and U.S. partners observing from Australia's Mount Stromlo, discovered the planet last July. They presented their findings at an American Astronomical Society meeting in the United States over the weekend. The two teams used a relatively new technique called gravitational microlensing, which essentially uses the chance alignment of dim and bright stars to detect potential planets.

This is the first discovery using the microlensing technique. It's the only technique that is sensitive to Earth-size planets, Bond said. The planet, which is around 30,000 light years away, cannot be seen directly and there was no way of confirming whether it has water or any of the elements that may support life, he added. Bond, with Auckland University associate professor Philip Yock and Japanese astronomers, will resume stargazing around the Milky Way in April for more extrasolar planets.

There are at least 17 known planets outside the solar system, but few are believed to be capable of sustaining life. The joint New Zealand-Japanese team is funded by both governments. (Reuter)