A Promising Exoplanet: LHS 1140 b Sheds Light on Potential Water and Atmosphere

Scientists have made significant progress in the search for habitable exoplanets with the help of the James Webb Space Telescope (JWST). LHS 1140 b, located just 49 light-years away in the constellation Cetus, has emerged as a top candidate for the presence of water and an Earth-like atmosphere.

This exoplanet, discovered by the MEarth Project in 2017, has long been a subject of exploration due to its ambiguous nature. It was initially believed to be a mini-Neptune gas giant but could potentially be a rocky, terrestrial planet instead. Scientific findings published in The Astrophysical Journal Letters, based on data collected by JWST in December 2023, shed light on LHS 1140 b’s potential for harboring an atmosphere and even a liquid water ocean.

Lead author Charles Cadieux, a doctoral student at the Université de Montréal, describes LHS 1140 b as a significant candidate in the search for liquid water beyond our solar system. The confirmation of water on the planet’s surface would mark a major breakthrough in the quest for habitable exoplanets.

While estimating that 10 to 20% of its mass is water, scientists consider the possibility that LHS 1140 b is either an ice planet or a “snowball.” The planet’s tidal lock to its star means that one side is always in darkness, much like the moon’s relationship with Earth. This perpetual darkness raises the possibility of a liquid ocean existing on the planet’s dark side, estimated to be roughly 2,500 miles (4,000 kilometers) in diameter, making it comparable in size to half of the Atlantic Ocean’s surface area. Moreover, the estimated surface temperature of this potential ocean is a comfortable 68 degrees Fahrenheit (20 degrees Celsius).

As a “super-Earth” seven times the mass of our own planet, LHS 1140 b orbits a red dwarf star, which is a common type of star in our Milky Way galaxy. Despite taking just 25 days to complete one orbit, LHS 1140 b remains in a habitable zone around its star, where water can exist in liquid form. This makes it a temperate world, unlike the extreme conditions experienced by Mercury, which takes 88 days to orbit the sun with surface temperatures reaching 800 degrees Fahrenheit (430 degrees Celsius).

Although the existence of an Earth-like atmosphere is yet to be confirmed, Ryan MacDonald, a NASA Sagan Fellow, expressed excitement over the tantalizing glimpse of an atmosphere on LHS 1140 b. Further observations by JWST will be required to investigate the presence of nitrogen and other gases, and to ultimately confirm the existence of liquid water on the planet’s surface. Given JWST’s limited observation capacity of only witnessing LHS 1140 b pass in front of its star eight times a year, several years of observations will be needed to obtain conclusive evidence.

The discovery of LHS 1140 b’s potential water and atmosphere offers new hope in the search for extraterrestrial life and emphasizes the importance of continued exploration and technological advancements in unraveling the mysteries of the universe.

FAQ:

1. What is LHS 1140 b?
LHS 1140 b is an exoplanet located 49 light-years away in the constellation Cetus. It is considered a top candidate for the presence of water and an Earth-like atmosphere.

2. How was LHS 1140 b discovered?
LHS 1140 b was discovered by the MEarth Project in 2017.

3. What was initially believed about LHS 1140 b?
Initially, LHS 1140 b was believed to be a mini-Neptune gas giant.

4. What has recent scientific findings revealed about LHS 1140 b?
Recent scientific findings, based on data collected by the James Webb Space Telescope (JWST), suggest that LHS 1140 b has the potential for harboring an atmosphere and even a liquid water ocean.

5. Who is Charles Cadieux?
Charles Cadieux is the lead author of the scientific findings and a doctoral student at the Université de Montréal.

6. What is the significance of water on LHS 1140 b?
The confirmation of water on the planet’s surface would mark a major breakthrough in the search for habitable exoplanets.

7. What are the possibilities regarding the composition of LHS 1140 b?
Scientists consider the possibility that LHS 1140 b is either an ice planet or a “snowball” due to the estimated 10 to 20% of its mass being water.

8. What is the unique characteristic of LHS 1140 b’s relationship with its star?
LHS 1140 b is tidally locked to its star, meaning one side is always in darkness. This raises the possibility of a liquid ocean existing on the planet’s dark side.

9. How does LHS 1140 b’s orbit compare to our own planet’s?
LHS 1140 b is a “super-Earth” seven times the mass of our own planet. It takes just 25 days to complete one orbit around its star.

10. Can life exist on LHS 1140 b?
The existence of an Earth-like atmosphere on LHS 1140 b is yet to be confirmed, but further observations by JWST will be required to investigate the possibility of the presence of nitrogen and other gases, as well as liquid water on the planet’s surface.

Definitions:
– Exoplanets: Planets that orbit stars outside of our solar system.
– MEarth Project: A project focused on discovering potentially habitable exoplanets.
– James Webb Space Telescope (JWST): A space telescope that has contributed to the search for habitable exoplanets.
– Tidal lock: When one side of a celestial body always faces the object it orbits, due to gravitational forces.
– Red dwarf star: A type of star that is smaller, cooler, and less luminous than our sun.
– Habitability zone: A region around a star where conditions may be suitable for liquid water to exist on the surface of an orbiting planet.

Suggested related links:
NASA
NASA Exoplanet Exploration
James Webb Space Telescope