How many exoplanets are there?
1901 known exoplanets were listed in March 2015 by the Extrasolar Planets Encyclopaedia. The catalogue is regularly updated and steadily growing. There are over 3000 so called candidates that wait for confirmation. Planets seem to be very common objects in the universe – the rule rather than the exception. An average galaxy like our Milky Way contains about 100 billion stars. Analysing data of NASA’s Kepler space observatory astronomers have estimated that there are at least 100 billion planets just in our galaxy.