The Webb Space Telescope has found no evidence of an atmosphere at one of the seven rocky, Earth-sized planets orbiting another star.
Scientists said that doesn’t bode well for the rest of the planets in this solar system, some of which are in the sweet spot for harbouring water and potentially life.
The Trappist solar system — a rarity with seven planets about the size of our own — has enticed astronomers ever since they spotted it just 40 light-years away. That’s close by cosmic standards; a light-year is about 5.8 trillion miles. Three of the seven planets are in their star’s habitable zone, making this star system even more alluring.
The NASA-led team reported little if any atmosphere exists at the innermost planet. Results were published in the journal Nature.
The lack of an atmosphere would mean no water and no protection from cosmic rays, said lead researcher Thomas Greene of NASA’s Ames Research Center.
Because the Trappist system’s innermost planet is bombarded by solar radiation — four times as much as Earth gets from our sun — it’s possible that extra energy is why there’s no atmosphere, Greene noted. His team found temperatures there hitting 450 degrees Fahrenheit (230 degrees Celsius) on the side of the planet constantly facing its star.
By using Webb — the largest and most powerful telescope ever sent into space — the US and French scientists were able to measure the change in brightness as the innermost planet moved behind its star and estimate how much infrared light was emitted from the planet.
The change in brightness was miniscule since the Trappist star is more than 1,000 times brighter than this planet, and so Webb’s detection of it “is itself a major milestone,” the European Space Agency said.
More observations are planned not only of this planet, but the others in the Trappist system. Looking at this particular planet in another wavelength could uncover an atmosphere much thinner than our own, although it seems unlikely it could survive, said Taylor Bell of the Bay Area Environmental Research Institute, who was part of the study.
Source: Oman News Agency