Probing Seven Worlds with NASA’s James Webb Space Telescope

On February 22, 2017, astronomers announced the discovery of seven Earth-sized planets around the star TRAPPIST-1, only 40 light-years away. Since then, they’ve been looking at next steps in exploring these worlds, and one has been to think about how the next-generation space telescope – Hubble’s successor, called the James Webb Space Telescope – will be able to help, after its October 2018 launch. Astronomers said last week (March 2, 2017) that it’ll be possible to use the new space telescope to find out if any of these planets might support life.

Sara Seager, astrophysicst and planetary scientist at MIT, commented in a NASA statement:

For thousands of years, people have wondered, are there other planets like Earth out there? Do any support life? Now we have a bunch of planets that are accessible for further study to try to start to answer these ancient questions.

Depending upon their atmospheric composition, at least three of TRAPPIST-1’s planets – e, f and g – could have the appropriate conditions for supporting liquid water. In other words, they orbit in the habitable zone of their star. Because the planets orbit a star that is small, a signal from them will be relatively large, and just strong enough for Webb to detect atmospheric features. Shawn Domagal-Goldman, an astrobiologist at NASA’s Goddard Space Flight Center said:

Two weeks ago, I would have told you that Webb can do this in theory, but in practice it would have required a nearly perfect target. Well, we were just handed three nearly perfect targets.

As big as a tennis court and as tall as a 4-story building, a full-scale model of the James Webb Space Telescope model was on display at the March 2013 South by Southwest Interactive Festival in Austin, Texas. The telescope – scheduled for an October 2018 launch – is Hubble’s successor and the largest space telescope to ever be built. Image via NASA.

Image from live webcam - April 26, 2016 - of the James Webb Space Telescope, now under construction at Goddard Space Flight Center.

Webb’s mirrors are coated with gold to optimize them for infrared light. Image via NASA.