Because Google is always in the events that run today's Doodle is dedicated to the seven planets found to be orbiting a star-dwarf and announced yesterday by NASA.
According to the US space agency, the dwarf star is located 40 light-years away from our planet (a cigarette road). 
The planets discovered by NASA, according to the space service announcement, are similar in size to the Earth and their surface is similar in temperature. This means that on their surface there is water in liquid form, which for scientists is considered a very good indication of the presence of life.
According to the scientists who made the announcement, the most suitable living conditions for the seven discovered planets prevail in at least three of them. Scientists are optimistic that three out of seven have the potential to find oceans.
Because this is a very rare discovery (for now and with the technical means εξερεύνησηof space we have), Google dedicated today's Doodle to yesterday's NASA revelation that made headlines all over the media.
