#earth-like

This is an artist's impression of innumerable Earth-like planets that have yet to be born over the next trillion years in the evolving universe.

Discovering signs of extraterrestrial life in the universe has been a highly sought-after field of inquiry throughout much of scientific history. Finding other life forms, whether they’re microscopic or similar to us, would undoubtedly revolutionize many areas of science and how we understand our place in the cosmos. While no real evidence has been found supporting the existence of extraterrestrial life, there are quite a few institutions dedicated to the search—and that search is continuing to get bigger.

Why Haven't Scientists Found 'Earth 2.0' Yet?

“Over the past 30 years, astronomers have gone from zero known extra-solar planets to thousands. Periodic changes in a star's motion or regular brightness dips give them away. Thanks to these techniques, we've revealed the masses and radii of worlds nearby and thousands of light years away. Over 200 are Earth-sized, with many residing in the so-called habitable zone around their stars. Yet with everything we've found, there are no potentially habitable Earth-like worlds around Sun-like stars.”

One of the greatest success stories over the past 30 years is the giant leap forward we’ve taken in understanding what worlds lie beyond our Solar System. We’ve gone, in that time, from exactly zero known planets beyond our Solar System to thousands. We’ve found worlds far larger than Jupiter, some of which revolve at distances interior to even Mercury’s orbit. We’ve found planets around blue supergiants and red dwarfs. And we’ve discovered small worlds, some of which are even smaller than Earth. Some of them even occur in the so-called habitable zone of their stars.