Exoplanet LHS 3844b May Host Life Despite Extreme Day‑Night Temperatures

The rocky exoplanet LHS 3844b, located about 48.5 light‑years from Earth and tidally locked to its red‑dwarf star, has one hemisphere that reaches 1,000‑2,000 K while the opposite side is near absolute zero. A team of researchers from the University of Pennsylvania, the Japan Agency for Marine‑Earth Science and Technology and Hokkaido University modeled the planet’s interior using a rectangular tank filled with viscous glycerol and temperature‑sensitive liquid crystals. Their experiment reproduced the stark day‑night temperature contrast and revealed a stable mantle circulation: hot material rises beneath the day side, flows toward the night side, cools, sinks, and returns underneath, forming a continuous “planetary pulse.” This circulation can create moderate‑temperature twilight zones and stationary mantle plumes that could act as geothermal oases, potentially supporting life and influencing magnetic‑field generation. The findings, published in *Nature Communications* (2025), suggest that tidally locked worlds previously dismissed as uninhabitable may merit renewed attention in the search for extraterrestrial life.