Exoplanets like LHS 3844b: Can eternal day and night sustain life?

LHS 3844b, an exoplanet located 48.5 light-years from Earth, has sparked interest regarding its potential to support life. Discovered in 2018 by NASA’s Transiting Exoplanet Satellite Survey, this planet orbits its star, LHS 3844, in just 11 hours. On July 10, 2026, researchers from the University of Pennsylvania, including postdoctoral researcher Daisuke Noto, explored this extreme environment's implications for habitability.

Understanding Tidal Locking and Its Effects

The phenomenon of tidal locking means that one side of LHS 3844b is constantly exposed to the star's heat, while the other side is in perpetual darkness. The temperatures on the day side can reach between 1,000–2,000 Kelvin, while the night side approaches absolute zero. Despite these extremes, Noto suggests that life might still exist in such harsh conditions.

Noto's team, in collaboration with the Japan Agency for Marine-Earth Science and Technology and Hokkaido University, published their findings in Nature Communications. They propose that tidal locking may create stable thermal environments that could support life. Noto stated, "Just looking at the extreme temperatures on the day and night sides might lead one to conclude these exoplanets are too harsh for life. But life might find a way."

Laboratory Experiments Mimic Exoplanet Conditions

To investigate the potential for life on LHS 3844b, Noto and his team created a laboratory model using a rectangular tank filled with viscous fluid. They used thermochromic liquid crystals to visualize temperature gradients, mimicking the extreme conditions present on the exoplanet. This setup allowed them to observe how heat distribution occurs under such unique circumstances.

• Hot fluid rises on the day side
• Fluid cools and sinks on the night side
• Creates a stable circulation pattern

Through this model, they found that the mantle flow settles into a consistent loop, resembling a planetary heartbeat. Noto noted, "It's slow and steady. Predictable. Kind of boring—but in a good way." This predictable behavior indicates that LHS 3844b may have localized geothermal conditions that could be conducive to life.

Potential Habitats on Tidally Locked Exoplanets

Noto's research suggests that the extreme temperature differences on LHS 3844b may lead to specific regions that could support life. The midlatitudes, where temperatures are more moderate, may provide the right conditions for the necessary ingredients for life.

In summary, while the conditions on LHS 3844b appear inhospitable at first glance, ongoing research indicates a possibility for life to exist in unexpected places. With further study, scientists hope to unravel the mysteries of these distant worlds and their potential for hosting life.