EXTRATERRESTRIAL life may exist on at least three planets in a newly discovered solar system just 39 light years from Earth, scientists believe.

A team of international astronomers, co-led by British scientist Dr Chris Copperwheat, detected seven Earth-sized worlds orbiting a cool dwarf star called TRAPPIST-1.

The six inner planets lie in a temperate zone capable of supporting life and at least three may have oceans - where life began on Earth.

No other star system known contains such a large number of Earth-sized and probably rocky planets.

Dr Copperwheat, from Liverpool John Moores University, said: “The discovery of multiple rocky planets with surface temperatures which allow for liquid water make this amazing system an exciting future target in the search for life.”

A robotic telescope operated by Liverpool John Moores University played a major role in the discovery, first reported in the journal Nature.

The Liverpool telescope supported observations made by Nasa's Earth-orbiting Spitzer telescope and helped detect the planets as they passed in front of their star.

Dr Copperwheat said: “As a robotic telescope and the largest in the world, the Liverpool telescope is very sensitive to the small, less-than-1 per cent dips in brightness through which the planets are discovered.

“It's all automated, it's flexible and fast, and so is ideal for this sort of time critical work.”

The planets were found using the “transit” method that looks for tiny amounts of dimming caused by a world blocking light from its star.

The Liverpool telescope is located on La Palma in the Canary Islands.