Audible's Exoplanet Drama Puts Habitable-World Questions in Focus

Audible offers the audio drama Exoplanet, written by Benjamin Percy and executive produced by Andy Weir. Its voice cast includes Anthony Mackie, Ariana DeBose and John Leguizamo. Audible members can access it through subscription tiers, and other listeners can purchase it separately.

Key details

• A star’s luminosity and a planet’s orbital distance affect how much energy the planet receives, factors astronomers use when assessing whether it lies in a habitable zone.
• A habitable zone describes a region where surface liquid water may be possible under suitable atmospheric conditions. A planet’s location there alone does not establish habitability.
• Planets around cool red dwarf stars generally need to orbit closer to their stars than Earth orbits the Sun to fall within the habitable zone.
• Ultraviolet and X-ray radiation can affect atmospheric chemistry and contribute to atmospheric loss. Astronomers also study starlight that passes through exoplanet atmospheres for molecular signatures.
• Oxygen makes up about 21% of Earth’s atmosphere, but pressure and other gases also matter when assessing whether an atmosphere is breathable.

Earth’s atmosphere contains about 21% oxygen, but oxygen alone does not establish that an atmosphere is breathable.

Why it matters

A planet’s location relative to its star offers only one part of the picture; radiation and atmospheric composition also shape whether surface conditions could support liquid water. Atmospheric molecules can help researchers investigate distant worlds, but astronomers must interpret those signatures alongside other conditions.