LEEVENSPARK

NASA's Kepler telescope has for the first time observed a planetary system with two planets passing in front of their star. The planets, now named named Kepler-9b and 9c, were seen transiting the sun-like star called Kepler-9. The announcement comes just days after ESO released data on a planetary system believed to have five orbiting planets, discovered with the HARP ground-based telescope. Kepler can measure the tiny drop in brightness that occurs when a planet transits a star; the size of the planet can be worked out from the scale of the dips. The time between dips gives the distance of the planet from the star, and variations in their regularity can be used to work out the planets' masses and detect other non-transiting planets in the system.   Kepler found more than 700 possible planets in its first 43 days, and has discovered five more systems that appear to have more than one transiting planet. "Kepler's high quality data and round-the-clock cov