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Researchers in New Zealand have taken measurements of the smallest planet outside the solar system.
Using the new MOA-II telescope at the Mt John Observatory, near Lake Tekapo in South Canterbury, they found the planet is three times bigger than Earth.
More than 300 planets have been found outside the solar system, and the latest is the smallest planet orbiting a normal star, as little as one 20th the mass of Earth's sun.
"It turns out that the lowest mass ones are the ones that would be easiest to search for evidence of life on other planets," the leader of the international search team, David Bennett from the University of Notre Dame, said in a statement.
The research would be published in the September issue of the Astrophysical Journal.
The tiny star is a "brown dwarf" 3000 light years from Earth.
"No planets have previously been found to orbit stars with masses less than 20 per cent that of the sun, but this finding indicates that even the smallest stars can host planets."
