Giant Helium Stream Found Escaping From “Super-Puff” Planet by James Webb Telescope
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Astronomers using NASA’s James Webb Space Telescope have
uncovered dramatic new evidence that a distant “super-puff” world is slowly
leaking its atmosphere into space. The exoplanet WASP-107b, located
roughly 210 light-years away, has been caught shedding a massive stream
of helium — a discovery that offers a rare look at how extreme starlight can
erode a planet over time.
A Giant Helium Tail Trails the Planet
New observations reveal that WASP-107b is wrapped in an
enormous helium cloud — one so large it stretches to nearly ten times the
planet’s radius. Instead of lingering behind the planet like a comet tail,
the helium is drifting both ahead of and behind the world as it orbits
its host star.
This unusual escape was detected by Webb’s NIRISS
infrared spectrograph, which spotted a slight dip in the star’s brightness
nearly 90 minutes before the planet itself crossed in front of it. That
early dimming signaled helium drifting far from the planet — marking the first
time atmospheric escape has ever been directly observed with JWST.
Meet the “Super-Puff” Losing Its Atmosphere
WASP-107b is no ordinary gas giant. Although its diameter is
nearly that of Jupiter, it contains only a fraction of Jupiter’s mass. This
gives it an extremely low density — as if a giant planet were “inflated” like a
balloon.
Because it orbits extremely close to its star — much closer
than Mercury sits from the Sun — it receives an intense blast of stellar
radiation. That energy heats the planet’s upper atmosphere, allowing gases like
helium to escape freely into space.
Webb’s analysis also picked up water vapor high in the
atmosphere, but no methane. This supports theories that WASP-107b once
formed farther from its star before migrating inward, where its atmosphere
began eroding under relentless heat.
Why This Discovery Matters
Atmospheric escape is one of the key processes that shape
the evolution of planets. Seeing it happen in real time helps scientists
understand:
- How
planets lose their atmospheres
- Why
some worlds become rocky while others remain gaseous
- How
close-orbiting planets might shrink or even vanish over billions of years
WASP-107b may be one of the clearest examples yet of a
planet being stripped down by its star.
#JWST #JamesWebb #SpaceNews #Exoplanet #NASA #Astronomy
#CosmicDiscovery #WASP107b #HeliumCloud #SpaceScience #Astrophysics
