sign of life. a huge win for these scientists. >> bill: kepler was launched in 2009. she is a work horse. >> it ended in 2013. scientists have been combing through the data and finding planets. they found a total of 219 new ones, 10 that could be earth-like. the grand total up to 4,000 planets they found. >> i'm reading seven of these planets orbit stars like our sun. what does that mean? >> we're comfortable on earth it is not too hot or too cold and we have liquid water and life. finding arrangements like that where they have a star just like our sun, they're in this kind of goldilocks zone where life could potentially exist. finding those planets and things that we're familiar with boosts that hope there is life out there. >> bill: you also say