Episode for August 2nd, 2023 Download

Aside from our own solar system, one of the most studied stellar systems lies about 40 light-years away in the direction of the constellation Aquarius. Using ground and space based telescopes like Spitzer, Kepler, Hubble, and, now, the James Webb Space Telescope, astronomers are looking hard at the seven rocky exoplanets orbiting the TRAPPIST-1 star.

The TRAPPIST-1 system, named after the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile, is currently the darling of both the astronomical community and the science-interested public. Discovered in 2016 by a team of astronomers in Belgium, this captivating system captured the attention of many because of its uncanny resemblance to our own solar system.

The TRAPPIST-1 system features a host star dramatically cooler and smaller than our Sun, classified as an ultra-cool dwarf. Its surrounding cohort consists of seven known planets. The planets are all named after letters of the alphabet, starting with b, the innermost planet, and ending with h, the outermost planet. The planets are so close together that they could all fit inside the orbit of Mercury.

In 2017, NASA announced the discovery that this system had the most Earth-sized planets found in the habitable zone of a single star. This system of seven rocky worlds–all of them with the potential for water on their surface – is an exciting discovery in the search for life on other worlds. There is the possibility that future study of this unique planetary system could reveal conditions suitable for life.

A bit later, a closer study of the seven planets suggested that some could harbor far more water than the oceans of Earth, in the form of atmospheric water vapor for the planets closest to their star, liquid water for others, and ice for those farthest away.

The form that water would take on TRAPPIST-1 planets would depend on the amount of heat they receive from their star, which is a mere 9 percent as massive as our Sun. Planets closest to the star are more likely to host water in the form of atmospheric vapor, while those farther away may have water frozen on their surfaces as ice.

Astronomers say we now know more about the TRAPPIST-1 system of planets than any other planetary system apart from our own. The excitement and hope that we may find life here is growing with every new observation.

While data from Hubble and Webb Space Telescopes have yet to confirm the existence of any atmospheres on any of these worlds, we have only just begun looking and hope abides with each new glance at this incredible system.