The James Webb space telescope, the most powerful telescope ever built, has gathered some extraordinary images since it was launched by Nasa just over a year ago. There have been shots of stars on the cusp of death, of stars violently colliding together, and even of ancient galaxies that have challenged our very understanding of the cosmos. But it’s the study of exoplanets – planets outside our solar system – that, for me, really justifies the telescope’s $10 billion price tag.

Since its launch (and for the preceding five years), I have been leading a team of 120 international astronomers working on the James Webb telescope, gathering images of exoplanets. Roughly speaking, there are four types: gas giants like Jupiter and Saturn; Neptunians, which typically have hydrogen- and helium-dominated atmospheres with cores of rock and heavier metals; super-Earths, bigger than our planet; and Terrestrials, which are compact with rocky surfaces, like Mercury, Venus, Earth and Mars. The vast majority orbit a star, though there are sunless rogue exoplanets that roam the galaxy in perpetual darkness.

Over the past decade or so, we’ve begun to understand just how widespread these planets are, including those resembling our world, known as exo-Earths. The first exoplanet, a Jupiter-like planet, was not confirmed until the early 1990s. Then, with the launch of the Kepler space mission in 2009, we began discovering a startling array of various solar systems with exotic planets orbiting their stars.

To read more, click here.