The detection of escaping helium around LHS 1140 b provides the first confirmed evidence of an atmosphere surrounding a rocky planet in another star’s habitable zone, strengthening its status as one of the most important worlds for studying whether potentially life-supporting conditions can exist beyond Earth.
By yourNEWS Media Newsroom
Astronomers have confirmed evidence of an atmosphere around LHS 1140 b, a distant super-Earth about 48 light-years from Earth, marking a major development in efforts to identify rocky planets beyond the solar system that may possess some of the basic conditions associated with habitability.
The discovery is particularly important because LHS 1140 b is believed to be a rocky or water-rich world rather than a gas giant.
Many of the exoplanets discovered so far resemble Jupiter or Neptune. Such planets are dominated by gas and lack an accessible solid surface where humans could theoretically establish settlements, cultivate food or obtain minerals. Terrestrial planets, by contrast, are composed primarily of rock and metal and may possess solid crusts.
LHS 1140 b may not be a straightforward larger version of Earth. Evidence suggests portions of the planet could be covered by deep oceans or ice. Even so, current observations indicate that it is not simply a smaller gas giant.
For a planet to allow humans to live outside fully enclosed habitats, several fundamental conditions would have to be satisfied.
There would need to be an accessible solid surface, or at minimum a sufficiently stable oceanic platform, capable of supporting settlements. Liquid water would be required for drinking, agriculture and the production of oxygen and fuel. A usable atmosphere would also have to provide suitable pressure and temperature, enough oxygen for respiration and no dangerous concentrations of other gases.
Meeting those conditions would still fall far short of guaranteeing that humans could live there.
Gravity would have to remain within tolerable limits. Radiation would need to be controlled. Settlers would require sustainable sources of food and energy, and the planet’s parent star would need to remain sufficiently stable over long periods.
Even with those uncertainties, finding a terrestrial world that possesses both water and an atmosphere represents an essential step in the search for potentially habitable planets.
Astronomers recently detected helium escaping from the upper atmosphere of LHS 1140 b. The observation represents the first confirmed detection of an atmosphere surrounding a rocky planet located within the habitable zone of another star, the orbital region where temperatures may permit liquid water to exist.
The helium signal appeared in observations collected in 2024 but was not seen in 2025, indicating that the rate at which the gas escapes may vary with time.
The result establishes that LHS 1140 b has an atmosphere, but it does not establish what humans would encounter closer to the planet’s surface.
The finding does not mean helium is the primary gas in the lower atmosphere. It also provides no evidence that the atmosphere contains free oxygen or that it would be breathable.
Harvard researchers have stressed the distinction between the helium-dominated upper atmosphere detected by astronomers and the still-undetermined composition of the atmosphere closer to the planet’s surface.
That distinction matters because a breathable atmosphere depends not on the presence of a single gas but on the proportions, pressure and interactions of several gases.
Earth itself illustrates the complexity.
Contrary to a common misconception, oxygen is not the dominant component of Earth’s atmosphere. Dry terrestrial air contains approximately 78% nitrogen, 21% oxygen, 0.9% argon and about 0.04% carbon dioxide, along with smaller amounts of other gases.
Nitrogen plays a critical role despite not being directly used by human lungs in significant quantities.
It acts as a buffer, diluting atmospheric oxygen and reducing the speed and intensity with which fires could otherwise spread. Nitrogen also helps maintain atmospheric pressure without exposing organisms to excessive concentrations of oxygen.
Life nevertheless depends heavily on nitrogen.
Nitrogen is required to make amino acids, proteins and DNA. Because most organisms cannot directly use atmospheric nitrogen gas, nitrogen-fixing microorganisms convert it into chemical forms that plants can absorb. Animals obtain nitrogen by eating plants or other animals.
An atmosphere dominated almost entirely by oxygen and carbon dioxide would therefore not provide a practical substitute for Earth’s atmospheric mixture.
Pure oxygen at pressure comparable to Earth would create an extreme fire hazard. Extended exposure to excessive oxygen pressure can also harm the lungs and nervous system.
Carbon dioxide is equally important in the correct amount.
Plants require it for photosynthesis, and it contributes to planetary warming. At excessive concentrations, however, carbon dioxide can produce headaches and confusion, followed by unconsciousness and eventually death.
For human respiration, the percentage of oxygen is only part of the equation.
What matters physiologically is oxygen partial pressure — the actual amount of oxygen available to enter the bloodstream. It must be high enough to sustain human metabolism without becoming sufficiently elevated to cause toxicity.
Helium presents a different set of considerations.
Hydrogen is the lightest element, followed by helium. Helium is chemically inert and is not intrinsically poisonous.
Under carefully controlled conditions, humans can breathe mixtures containing helium and oxygen.
Hospitals sometimes use heliox, a mixture of helium and oxygen, because helium’s low density allows the gas mixture to move more easily through narrowed airways. Deep-sea divers also substitute helium for some of the nitrogen in their breathing mixtures to reduce the risk of nitrogen narcosis.
A helium-and-oxygen atmosphere could theoretically support human breathing if it contained the proper amount of oxygen, maintained appropriate overall pressure and lacked dangerous gases.
No free oxygen, however, has yet been detected in the lower atmosphere of LHS 1140 b.
Living in such an atmosphere would also produce a familiar acoustic effect: altered voices.
Helium does not cause the vocal cords themselves to vibrate more rapidly. Instead, it changes the resonant frequencies of the mouth and throat because sound propagates through helium much faster than through ordinary air.
Sound travels through normal air at approximately 767 miles per hour. In helium, it moves at roughly 2,140 miles per hour, nearly three times as fast.
Helium’s chemical inertness should not be confused with safety when inhaled improperly.
Breathing pure helium from balloons replaces oxygen in the lungs. Repeated inhalation can cause hypoxia, loss of consciousness, permanent brain injury or death.
Breathing helium from a pressurized cylinder presents an even greater danger because high-pressure gas can rupture lung tissue or enter the bloodstream under pressure.
Understanding exactly what surrounds LHS 1140 b will require further spectroscopy.
Astronomers analyze exoplanet atmospheres by studying light as a planet crosses in front of its star. During a transit, a minute amount of starlight passes through the planet’s atmosphere before reaching telescopes.
Different molecules absorb specific wavelengths of light. Oxygen, water vapor, methane, carbon dioxide and other substances therefore leave recognizable chemical signatures in the resulting spectrum.
Scientists can search for molecular oxygen directly and can also look for ozone, which forms from oxygen.
Even the detection of oxygen, however, would not by itself establish that life exists.
Ultraviolet radiation can break apart water molecules. Under the right circumstances, that process could leave substantial oxygen behind without any biological activity.
Researchers therefore seek combinations of gases that would be difficult to maintain simultaneously without continual replenishment.
A mixture involving oxygen or ozone along with methane, water vapor and carbon dioxide could provide a more significant clue because those gases interact chemically and may require an ongoing process to keep them present together.
The James Webb Space Telescope can continue observing LHS 1140 b, but the challenge is substantial. The signals generated by a distant planetary atmosphere are extraordinarily weak and can be difficult to distinguish from activity originating on the host star.
A new generation of instruments could improve those measurements.
The European Extremely Large Telescope is expected to begin scientific operations near the end of this decade. Its high-resolution spectroscopy capabilities will allow scientists to examine the atmospheres of smaller planets with greater precision.
Its planned ANDES instrument is specifically intended to characterize the atmospheres of Earthlike exoplanets.
NASA is also developing the Habitable Worlds Observatory, a future space telescope designed to directly image at least 25 potentially habitable planets and examine their atmospheres for gases including oxygen and methane.
The project remains conceptual and is not expected to launch before the late 2030s or later.
Artificial intelligence is also expected to become increasingly important in interpreting the enormous amounts of data produced by exoplanet studies.
AI systems can compare vast numbers of atmospheric models, detect extremely faint spectral patterns, distinguish planetary signals from stellar variability and instrument noise, and help astronomers determine which targets deserve limited telescope observation time.
NASA has already used the ExoMiner artificial intelligence system to validate hundreds of exoplanets. Its newer ExoMiner++ system is being applied to observations from both the Kepler and TESS missions.
AI cannot overcome the fundamental limitation of observation, however.
If a telescope never captures the necessary light, an algorithm cannot reconstruct information that was never collected. Larger, more sensitive instruments remain essential.
The nature of LHS 1140 b’s star adds another layer to the question of habitability.
Earth orbits the sun, a G-type yellow-dwarf main-sequence star. The sun is larger, hotter and more luminous than a red dwarf. At approximately 4.5 billion years old, it is believed to be roughly halfway through the primary phase of its estimated 10-billion-year lifespan.
LHS 1140 is an M-type red dwarf.
Red dwarfs are smaller, cooler and dimmer than the sun, but they can survive far longer. Because they release less energy, their habitable zones sit much closer to the star.
That proximity creates potential complications.
Planets orbiting closely around red dwarfs are frequently tidally locked, meaning one side perpetually faces the star while the opposite side remains turned away.
Many red dwarfs also produce powerful flares capable of bombarding nearby planets with radiation and stripping away their atmospheres.
LHS 1140 appears to be comparatively quiet for a red dwarf, one reason its planet has attracted particular interest.
Gravity Matters
Even if LHS 1140 b eventually proves to have water and a chemically favorable atmosphere, its gravity could present a major obstacle to human settlement.
NASA estimates that the planet has approximately 5.6 times Earth’s mass while measuring about 1.73 times Earth’s radius.
Those figures imply surface gravity of roughly 1.87 times that experienced on Earth.
A person who weighs 180 pounds on Earth would effectively weigh approximately 337 pounds on LHS 1140 b.
Someone weighing 220 pounds on Earth would experience a weight equivalent to about 411 pounds.
The long-term effects of living permanently under such gravity are unknown.
Humans raised in that environment might develop stronger bones, muscles and cardiovascular systems as they adapted from birth. The persistent additional load could instead produce significant medical complications.
Over many generations, an isolated population exposed continuously to greater gravity might undergo evolutionary changes.
Possible adaptations could include shorter and stockier bodies, denser bones, stronger back and leg muscles and broader feet capable of distributing body weight more effectively.
Given sufficient reproductive isolation and evolutionary time, descendants of settlers could eventually become substantially different from modern humans and might conceivably develop into a separate species.
That possibility remains informed speculation, not a scientific prediction.
The planet itself may also differ dramatically from Earth.
LHS 1140 b could be a water-rich world covered substantially by ocean rather than continents. It may contain a global ocean beneath an icy shell, or it could maintain a region of liquid water near the point permanently facing its star.
Scientists have not confirmed the composition of its lower atmosphere.
Nitrogen, carbon dioxide and water vapor may be present, but those possibilities have yet to be established observationally.
Earlier James Webb observations placed LHS 1140 b among the leading candidates for detailed study as a potentially habitable water world.
Other nearby exoplanets also remain important targets.
Proxima Centauri b is only about 4.2 light-years from Earth, making it far closer than LHS 1140 b. Its star, however, is highly active and produces powerful flares that may have removed much of the planet’s atmosphere.
The TRAPPIST-1 system contains several Earth-sized planets located within or near the habitable zone of their star.
Astronomers have not yet confirmed substantial atmospheres around the most promising of those planets.
That leaves LHS 1140 b as arguably one of the most promising known exoplanets for studying a potentially habitable atmosphere.
Promising for research does not necessarily mean practical for colonization.
The planet’s estimated gravity, possible global ocean, likely tidal locking and unknown atmospheric chemistry could each present formidable obstacles to human survival.
Clues from Meteorites
Evidence from meteorites provides another piece of the broader question of whether the chemical ingredients associated with life may be widespread beyond Earth.
A meteorite that crashed through a home in Hillsborough, New Jersey, in July 2024 was later found to contain amino acids, other organic molecules and evidence of ancient salty water.
The meteorite weighed roughly three pounds.
Amino acids are often called the building blocks of life because they join together in numerous combinations to form proteins.
Proteins are fundamental to living cells.
They help create cellular structure, transport materials, communicate chemical signals, protect organisms from disease and operate as enzymes that accelerate the chemical reactions necessary for metabolism, growth and reproduction.
The Hillsborough meteorite is classified as an unusually pristine carbonaceous chondrite.
Researchers detected numerous amino acids in the object, including varieties that are uncommon on Earth, and believe the meteorite may have originated from asteroid 163 Erigone.
The discovery does not stand alone.
The Murray meteorite, which fell in Kentucky in 1950, contained extraterrestrial amino acids. So did the Murchison meteorite, which fell in Australia in 1969.
Samples returned directly from the asteroids Ryugu and Bennu have likewise contained amino acids and other organic compounds connected with the chemistry of life.
Together, those discoveries demonstrate that important organic compounds can form naturally in space without first being produced by living organisms.
That raises the possibility that asteroids and meteorites helped supply the early Earth with water, amino acids and additional organic materials that later became raw ingredients for the first living systems.
If such compounds are routinely transported among worlds, Earth may not be unusual in receiving the chemical components necessary for biological chemistry.
LHS 1140 b could theoretically have experienced the same process.
A planet possessing an atmosphere, possible liquid water and a source of energy could also have been bombarded for billions of years by meteorites carrying amino acids and other organic compounds.
Such delivery would not mean life necessarily emerged there.
Amino acids are chemicals, not organisms, and their presence alone does not cause a living system to form.
The distinction can be compared with the materials needed to construct a house. A hardware store can contain lumber, nails, concrete and every other necessary component, but those materials do not organize themselves into a finished structure.
Life similarly requires more than chemical ingredients.
It needs a means of storing and transmitting genetic information, boundaries resembling cellular membranes, a continuing source of energy and some form of self-replicating chemical system.
The Hillsborough meteorite therefore does not demonstrate that extraterrestrial life exists.
Its significance lies in showing that the universe can independently manufacture and distribute some of the same molecular ingredients upon which terrestrial life depends.
The findings from meteorites and the observations of LHS 1140 b address different parts of the same larger question.
LHS 1140 b shows that a rocky or water-rich planet can retain an atmosphere while orbiting within the habitable zone of a red dwarf.
Meteorites and asteroid samples show that water, amino acids and other organic compounds can be produced beyond Earth and transported through space.
Neither discovery establishes that life exists elsewhere.
For now, Earth remains the only world known to combine abundant liquid surface water, breathable air, tolerable gravity, fertile soil, atmospheric protection, a comparatively stable parent star and a thriving biosphere.
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