Quote"Our observations suggest that between 20% and 60% of Sun-like stars have evidence for the formation of rocky planets not unlike the processes we think led to planet Earth," he said. "That is very exciting." Mr Meyer's team used the US space agency's Spitzer space telescope to look at groups of stars with masses similar to the Sun. They detected discs of cosmic dust around stars in some of the youngest groups surveyed. The dust is believed to be a by-product of rocky debris colliding and merging to form planets. Nasa's Kepler mission to search for Earth-sized and smaller planets, due to be launched next year, is expected to reveal more clues about these distant undiscovered worlds.