Are There Other Earths Out There? Astronomers’ First Clues to an Answer Date Back 100 Years
Of all the questions that science might hope to answer, few excite people more than "is there life on worlds other than our Earth, and, if so, do any alien creatures possess intelligence comparable to that of human beings?” But how can we find rocky Earth-like worlds that orbit around stars other than our Sun? Remarkably, the first astronomical evidence that such worlds exist dates back 100 years! This evidence involved observation of the type of star that our Sun will become five billion years from now, something called a "white dwarf" star. Such studies have shown that rocky worlds with compositions similar to that of Earth are common throughout our Milky Way galaxy. Thus future prospects are bright for finding rocky planets suitable for hosting life.