
This artist’s concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets’ diameters, masses and distances from the host star. The James Webb is expected to begin science observations this summer. (NASA/JPL-Caltech)
The decades-long process of developing, refining, testing, launching, unfurling and now aligning and calibrating the most capable space telescope in history is nearing fruition. While NASA has already released a number of “first light” images of photons of light moving through the James Webb Space Telescope’s optical system, the jaw-dropping “first light” that has all the mirrors up and running together to produce an actual scientific observation is a few months off.
Just as the building and evolution of the Webb has been going on for years, so has the planning and preparation for specific team observation “campaigns.” Many of these pertain to the earliest days of the universe, of star and galaxy formation and other realms of cosmology, but an unprecedented subset of exoplanet observations is also on its way.
Many Worlds earlier discussed the JWST Early Release Science Program, which involves observations of gigantic hot Jupiter planets to both learn about their atmospheres and as a way to collect data that will guide exoplanet scientists in using JWST instruments in the years ahead.
Now we’ll look at a number of specific JWST General Observation and Guarantreed Time efforts that are more specific and will collect brand new information about some of the major characteristics and mysteries of a representative subset of the at least 100 billion exoplanets in our galaxy.
This will be done by using three techniques including transmission spectroscopy — collecting and analyzing the light that passes through an exoplanet’s atmosphere as it passes in front of its Sun. The JWST will bring unprecedented power to characterizing the wild diversity of exoplanets now known to exist; to the question of whether “cool” and dim red dwarf stars (by far the most common in the galaxy) can maintain atmospheres; to newly sensitive studies of the chemical makeup of exoplanet atmospheres; and to the many possibilities of the TRAPPIST-1 exoplanets, a seven rocky planet solar system that is relatively nearby.

An artist’s interpretation of GJ 1214b,one of a group of super-Earth to mini-Neptune sized planets to be studied in the JWST Cycle1 observations. The planet is known to be covered by a thick haze which scientists expect the JWST to pierce as never before and allow them to study atmospheric chemicals below.