Solar System 2.0? James Webb data sheds new light on Earth-like planet

A Solar System 2.0?

All planets in the TRAPPIST-1 system had been previously observed with the transmission spectroscopy technique using the Hubble or Spitzer Space Telescopes.

A July 2016 study based on the Hubble data showed that TRAPPIST-1b and c were unlikely to have hydrogen-dominated atmospheres like the ones typical of gas giants. This strengthened the case that these planets were likely rocky and could possibly hold onto liquid water.

However, no atmospheric features had ever been detected in the exoplanets of the star system, despite the fact that the four closest planets were in the habitable zone of their star system.

The researchers used Webb's Mid-Infrared Instrument (MIRI) to observe mid-to-long wavelength radiation emanating from the exoplanet TRAPPIST-1b. The planet is the closest to the system's M dwarf star and it orbits its host star in only 1.9 Earth days.

It receives four times as much irradiation as the Earth receives from the Sun, meaning thermal emissions from the exoplanet could be measurable and could shed light on the planet's atmosphere.

TRAPPIST-1b shows no signs of habitability

Now, a new paper published in the journal Nature outlines the new observations and shows that TRAPPIST-1b shows no sign of an atmosphere.

The researchers detected the planet's secondary eclipse (when it passes behind its M dwarf host star), allowing them to measure the planet's daytime temperature and its atmospheric properties.

The authors wrote that the most straightforward interpretation of their findings is that the planet has little or no atmosphere redistributing radiation from the host star. They also detected no atmospheric absorption from carbon dioxide or other species. The absence of an atmosphere is consistent with results from modeling predictions, the researchers explained. Still, the researchers say follow-up observations will afford us a better understanding of the entire TRAPPIST-1 solar system.