Kepler Discovers Smallest Exoplanet

摘要

Mercury, with a diameter of 4,879 km is the smallest planet of our solar system. NASA's Kepler space telescope has now discovered what is claimed to be the smallest planet outside the solar system - much smaller than Mercury - in a star system called Kepler-37. This is a remarkable discovery as far as exoplanets (planets orbiting stars other than the Sun) are concerned because most of the hitherto discovered exoplanets are much larger than our Earth - some as large as Jupiter. Till date, 861 planets have been discovered outside our solar system.