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Habitable Zones & Global Climate: April 2021


Almost half a century ago the creators of Star Wars imagined a life-sustaining planet, Tatooine, orbiting a pair of stars. Now, 44 years later, scientists have found new evidence that that five known systems with multiple stars, Kepler-34, -35, -38, -64 and -413, are possible candidates for supporting life.

We present a brief overview of the main effects by which a star will have an impact (positive or negative) on the surface habitability of planets in orbit around it.

Understanding when global glaciations occur on Earth-like planets is a major challenge in climate evolution research. Most models of how greenhouse gases like CO2 evolve with time on terrestrial planets are deterministic, but the complex, nonlinear nature of Earth's climate history motivates study of non-deterministic climate models.

A large fraction of known terrestrial-size exoplanets located in the Habitable Zone of M-dwarfs are expected to be tidally-locked. Numerous efforts have been conducted to study the climate of such planets, using in particular 3-D Global Climate Models (GCM).

Raindrops on other planets and moons are close to the size of raindrops on Earth despite having different chemical compositions and falling through vastly different atmospheres, a new study finds.

It is not currently possible to create a living organism ab initio due to the overwhelming complexity of biological systems.

The nearly logarithmic radiative impact of CO2 means that planets near the outer edge of the liquid water habitable zone (HZ) require ∼106x more CO2 to maintain temperatures conducive to standing liquid water on the planetary surface than their counterparts near the inner edge.

New research shows the permanent rise of oxygen in our atmosphere, which set the stage for life as we know it, happened 100 million years later than previously thought.