COMPLETE GUIDE TO EXOPLANETS

Our knowledge of worlds beyond the Solar System has exploded in the last three decades

- Robert Lea

Ever since humans first discovered that the stars in the night sky were bodies similar to our Sun, we’ve dreamed and speculated about the worlds that could orbit these stars. Would they be rocky terrestrial planets like Earth? Could they possess liquid water? Could the presence of this vital life-sustaining element on other worlds mean that we are not alone in the universe?

“For millennia, humans have been asking the question of whether we are alone. And tied to that question, are other planets anywhere else?” Nikku Madhusudhan, a professor of astrophysics and exoplanetary science at the Institute of Astronomy of the University of Cambridge, tells All About Space. “It’s very fundamental to being human to ask the question if there are planets elsewhere.”

With this considered, it’s almost shocking to think that before the 1990s astronomers weren’t even certain that stars outside the Solar System possessed their own planets. There was no evidence to suggest that extrasolar planets, or exoplanets for short, didn’t exist, nor were there hints that the Solar System was in any way unique in the Milky Way. But until the very end of the 20th century, astronomers had been frustrated by the lack of direct evidence of worlds beyond the influence of our star.