Atmosphere detected on rocky exoplanet LHS 1140 b
Astronomers have detected an atmosphere on the rocky exoplanet LHS 1140 b, located in the habitable zone, making it the best candidate for life beyond Earth.
The Full Story
A plain summary built from the channels that reported this story.
Astronomers have detected an atmosphere around a rocky, Earth-like planet outside our solar system, marking a significant step in the search for life beyond Earth. The planet, named LHS 1140 b, is located 49 light-years away and sits within the habitable zone of its star. It is slightly larger than Earth and is now considered the best candidate discovered so far for hosting life.
The detection was made using the transit method, where a planet passes in front of its star and some of the starlight filters through the planet's atmosphere. In this case, scientists identified helium in the upper atmosphere. The presence of helium, combined with the absence of hydrogen, suggests the planet is not a gas giant like Uranus or Neptune but something more akin to a rocky world. The upper atmosphere of Earth also contains helium.
Researchers at Harvard University led the study. They found that the helium signal is consistent with a denser lower atmosphere, which could potentially contain liquid water. However, they have not yet confirmed the presence of water. The detection of an atmosphere itself is a milestone, as it was previously unclear whether rocky planets in the habitable zone of their stars could retain an atmosphere.
The habitable zone is a theoretical region where, under similar conditions to Earth, water could remain liquid for billions of years. LHS 1140 b falls within this zone, making it a priority for further study. Now that an atmosphere is confirmed, astronomers plan to use more powerful telescopes to analyse its chemical composition. The ultimate goal is to search for biosignatures, such as oxygen produced by plants or algae, which would be the first evidence of life beyond Earth.
While the discovery does not prove that life exists, it provides a strong reason to investigate further. The planet is now a prime target for future observations, including those from the James Webb Space Telescope.
On screen
Stills are sampled automatically at 60-second intervals. Where shown, the still is the nearest available frame from the relevant broadcast segment and is included to show what was on screen during that part of the broadcast. A still may not correspond to the exact second of a quoted phrase.
Key Claims
Claims reported during this story's coverage, mapped by channel. Ordered by how many channels carried each claim.
| Claim | BBC NEWS |
|---|---|
| Detection of helium in the upper atmosphere of LHS 1140 b suggests a denser lower atmosphere that could contain liquid water. | |
| Exoplanet LHS 1140 b is 49 light-years away and slightly larger than Earth. | |
| LHS 1140 b is considered the best candidate discovered so far for hosting life beyond our solar system. | |
| LHS 1140 b is within its star's habitable zone, where liquid water could exist. | |
| The atmosphere of LHS 1140 b contains helium and no hydrogen, distinguishing it from gas giants. |
Channel Perspectives
What each channel focused on, with key quotes.
The BBC focused on an in-depth interview with Professor Amaury Triaud, an exoplanetologist, to explain the science behind the discovery in an accessible way. The tone was educational and slightly light-hearted, with the presenter joking about aliens at the end. The coverage emphasised the milestone nature of the detection and the potential for future discoveries.
- “Astronomers have detected an atmosphere around a rocky Earth-like planet outside our solar system that could have liquid water on its surface.”
- “What has been told is that the atmosphere has helium. That's the only thing that has been detected so far.”
- “Now that we know this planet has an atmosphere, because it was unclear whether rocky planets in the habitable zone of the star did outside of the solar system. So this is a big milestone.”
Broadcast Timeline
News broadcasts tracked for this story, in time order.