Updated

Updated · Hackaday · Jul 20

LHS 1140 b Shows Helium Escape, Hinting at Earth-like Atmosphere 49 Light-Years Away

Updated

Updated · Hackaday · Jul 20

LHS 1140 b Shows Helium Escape, Hinting at Earth-like Atmosphere 49 Light-Years Away

Q: Scientists detected helium escaping this distant world. Why is this gas a critical clue in the search for a second Earth?

Helium is a critical clue because its escape is strong evidence that LHS 1140 b still has an atmosphere — and an atmosphere is one of the basic requirements for an Earth-like, potentially habitable world. On its own, helium does not mean life. What makes the detection important is what it reveals about the planet’s atmospheric structure and history. Helium is light and easy for a planet to lose, especially around red dwarf stars that can strip atmospheres away. If astronomers can see helium escaping now, it suggests LHS 1140 b has retained a substantial atmosphere for billions of years rather than ending up as a bare rock. The signal also points to a helium-rich upper atmosphere that is depleted in hydrogen. That matters because a thick hydrogen envelope would make the planet more like a mini-Neptune than Earth. A hydrogen-poor atmosphere is more consistent with a rocky world that may have evolved toward a secondary atmosphere containing heavier gases such as carbon dioxide, water vapor, and possibly oxygen-bearing compounds. In practical terms, helium gives astronomers a detectable tracer. It is easier to spot in transit observations than many lower-atmosphere gases, so it can confirm that a temperate rocky planet has air at all. That makes LHS 1140 b a much stronger target for follow-up studies with telescopes such as JWST, which can search for the fuller chemical mix needed to judge whether the planet could truly resemble Earth.

3 articles · Updated · Hackaday · Jul 20

Science paper observations suggest LHS 1140 b may have an Earth-like atmosphere after detecting time-variable helium escaping from the planet.
That escape points to a helium-rich upper atmosphere depleted in hydrogen, a combination researchers say strengthens the case that the super-Earth is not a gas-dominated world.
LHS 1140 b orbits a red dwarf every nearly 25 days and receives less than half the sunlight Earth gets, leaving any proposed ocean surface comparatively dim despite potentially temperate conditions.
At 49 light-years away, the planet remains far beyond direct inspection for now, so the atmospheric interpretation still awaits confirmation even as it joins the shortlist of plausibly habitable exoplanets.

Sources

Hackaday1d ago

Exoplanet LHS 1140 b Shows Signs of Earth-like Atmosphere from Helium Escape

New York Post 1d ago

Aliens most likely to inhabit 'super-Earth' LHS 1140b: astronomers

ScienceBlog.com1d ago

Astronomers just confirmed the first atmosphere around a rocky planet in another star's habitable zone — and the gas leaking from LHS 1140b is the part that actually matters - ScienceBlog.com

6 Sources

Scientists detected helium escaping this distant world. Why is this gas a critical clue in the search for a second Earth?

This super-Earth has a potential atmosphere, but can the Webb Telescope finally confirm if a rocky exoplanet can harbor life?

Breakthrough Detection: Helium Atmosphere Found on Habitable-Zone Rocky Exoplanet LHS 1140 b

Overview

Scientists have made a landmark discovery by detecting a helium-dominated atmosphere around the rocky exoplanet LHS 1140 b, which orbits within its star's habitable zone. This is the first time an atmosphere has been confirmed on a rocky planet in such a region, marking a major step in the search for potentially habitable worlds. The presence of an atmosphere is crucial, as it can shield the planet from cosmic radiation, allow liquid water to exist on the surface, and help regulate climate—key factors for life. This breakthrough opens new possibilities for studying habitability beyond our solar system.

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