NASA is engaged in planning for a Habitable Worlds Observatory (HabWorlds), a coronagraphic space mission to detect rocky planets in habitable zones and establish their habitability.
![Phase curves of the normalised total and normalised linearly polarised flux of a cloudy planet with a wavy ocean surface and an Earth-like atmosphere in an edge-on orbit (adapted from Trees & Stam 2019). The wind speed over the ocean—which determines the wave height (Cox & Munk 1954)—is 7 m/s, and the clouds consist of spherical water droplets. The cloud coverage fraction is 0.5, and while the cloud pattern is patchy, the glint is always cloud-free. The fluxes are normalised such that the total (i.e., unpolarised + polarised) flux equals the planet’s geometric albedo at phase angle 𝛼 = 0 ◦ . In the bottom panel, we illustrate the scattering angle ranges of glories, rainbows, Rayleigh scattering, and ocean glint. Note that the features in the actual curves partly overlap. The glory illustration is taken from Zakovryashin & Prigarin (2020); all other illustrations are from unsplash.com [1, 2, 3]. This figure is best viewed in colour. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2023/07/chasing-1.png?resize=1200%2C720&ssl=1)
NASA is engaged in planning for a Habitable Worlds Observatory (HabWorlds), a coronagraphic space mission to detect rocky planets in habitable zones and establish their habitability.