Nature Communications study from Penn shows stable mantle convection on tidally locked exoplanets like LHS 3844b

Daisuke Noto and colleagues constructed a rectangular tank filled with viscous glycerol seeded with thermochromic crystals to replicate mantle conditions on LHS 3844b. Four thermostats imposed day-night and surface-interior temperature gradients matching the 48.5-light-year planet’s expected extremes. The setup produced one continuous circulation loop: hot fluid rose beneath the heated side, flowed laterally, cooled, and sank on the cold side before returning at depth.

The resulting flow was laminar and predictable rather than chaotic, with occasional mushroom plumes rising from the base. This pattern implies that tidal locking can create localized habitable thermal niches within the mantle even when surface temperatures range from 1000 K to near absolute zero. Because M-dwarfs host most nearby planets and tidal locking is common at close-in orbits, the mechanism applies to a large fraction of potentially observable worlds.

Mainstream coverage emphasizes surface habitability; the deeper insight is that interior heat transport may buffer against global freezing or boiling. The analog experiment omits realistic mantle rheology and radiogenic heating, limiting quantitative extrapolation. Next, coupling these tank results to 3-D numerical models and JWST phase-curve data on LHS 3844b will test whether the predicted circulation produces detectable atmospheric signatures within the next two years.