There are several reasons for this

There are several reasons for this confidence, but a main one has to do with the speed at which scientists have been discovering planets outside of our own Solar System. In 2000, astronomers knew of about 50 of these ‘exoplanets’. By 2013, they had found almost 850, located in over 800 planetary systems. That number may reach one million by the year 2045, says David Weintraub, associate professor of Astronomy at Vanderbilt University, and author of Religions and Extraterrestrial Life. “We can quite reasonably expect that the number of known exoplanets will soon become, like the stars, almost uncountable,” he writes. Of those discovered so far, more than 20 are Earth-size exoplanets that occupy a “habitable” zone around their star, including the most recently discovered Proxima b, which orbits Proxima Centauri.

結果 (英文) 3:

There are several for this confidence, but a one to do the speed at scientists have been discovering planets outside of with our own Solar main System. which has In 2000, astronomers of about 50 of these 'exoplanets'. By 2013, they had almost found, located in over 800 planetary systems. That number may one by the year 2045, says David million, associate professor Astronomy at Vanderbilt University, and author of and Religions Extraterrestrial Life. of Weintraub reach "We can reasonably expect the number known will soon become, like the stars, almost uncountable," he writes., exoplanets of that quite Of those discovered so far more than are Earth-size exoplanets that occupy 20 a "habitable" zone around their star, including the most recently discovered Proxima B, which orbits Proxima Centauri.