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Title: Most Earth-Like Planet Yet May Have Been Found Just 40 Light Years
Away

Link: https://science.slashdot.org/story/25/09/13/0...

One of the worlds in the TRAPPIST-1 system, a mere 40 light-years away, just
might be clad in a life-supporting atmosphere," reports ScienceAlert. "In
exciting new JWST observations, the Earth-sized exoplanet TRAPPIST-1e shows
hints of a gaseous envelope similar to our own, one that could facilitate
liquid water on the surface." Although the detection is ambiguous and needs
extensive follow-up to find out what the deal is, it's the closest
astronomers have come yet in their quest to find a second Earth... [T]he
first step is finding exoplanets that are the right distance from their host
star, occupying a zone where water neither freezes under extreme cold nor
evaporates under extreme heat. Announced in 2016, the discovery of the
TRAPPIST-1 system was immediately exciting for this reason. The red dwarf
star hosts seven exoplanets that have a rocky composition (as opposed to gas
or ice giants), several of which are bang in the star's habitable, liquid
water zone... Red dwarf stars are also much more active than Sun-like stars,
rampant with flare activity that, scientists have speculated, may have
stripped any planetary atmospheres in the vicinity. Closer inspections of
TRAPPIST-1d, one of the other worlds in the star's habitable zone, have
turned up no trace of an atmosphere. But TRAPPIST-1e is a little more
comfortably located, at a slightly greater distance from the star... [T]he
spectrum is consistent with an atmosphere rich in molecular nitrogen, with
trace amounts of carbon dioxide and methane. This is pretty tantalizing.
Earth's atmosphere is roughly 78 percent molecular nitrogen. If the results
can be validated, TRAPPIST-1e might just be the most Earth-like exoplanet
discovered to date. That is not a small if, though. Luckily, more JWST
observations are in the pipeline, and the researchers should be able to
validate or rule out an atmosphere very soon. After analyzing four transits
of TRAPPIST-1e across TRAPPIST-1, "We are seeing two possible explanations,"
says astrophysicist Ryan MacDonald of the University of St Andrews in the UK.
"The most exciting possibility is that TRAPPIST-1e could have a so-called
secondary atmosphere containing heavy gases like nitrogen. "But our initial
observations cannot yet rule out a bare rock with no atmosphere..."
Astrophysicist Ana Glidden of MIT led the second team interpreting the
results, and says "We are really still in the early stages of learning what
kind of amazing science we can do with Webb. It's incredible to measure the
details of starlight around Earth-sized planets 40 light-years away and learn
what it might be like there, if life could be possible there." "We're in a
new age of exploration that's very exciting to be a part of."

Read more of this story at Slashdot.

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