Ironically, the sunscreen snow only falls on the planet's perpetually dark side.
Recently, NASA’s Hubble Space Telescope has found a planet that snows sunscreen.
The giant planet, known to NASA as Kepler-13Ab, is an exoplanet, or a planet not inside our solar system. The “sunscreen snow” is actually titanium oxide precipitation, the main ingredient in sunscreen.
However, in an ironic twist, it only snows titanium oxide on the permanently-nighttime side.
Astronomers suggested that the planets perpetually dark side hosts low temperatures that crystalize the titanium oxide precipitation, which then forms clouds and falls as snow.
Kepler-13Ab also has a strong gravitational pull, which keeps the sunscreen clouds and snow stuck in its atmosphere.
The discovery of the sunscreen snow came by accident. The astronomers using the Hubble telescope originally set out to observe the giant planet’s atmosphere. The fact that the planet doesn’t rotate created two separate atmospheres, one on the daytime side and one on the nighttime side, similarly to Earth’s moon. The phenomenon is known as “tidal lock.”
The discovery of the two atmospheres is what led to the discovery of the sunscreen snow.
Astronomers hope that the discovery will provide new insight into how a foreign planet’s weather system functions and believe it could one day play a part in analyzing new planets for habitability.
“In many ways, the atmospheric studies we’re doing on hot Jupiters now are testbeds for how we’re going to do atmospheric studies on terrestrial, Earth-like planets,” said Thomas Beatty of Pennsylvania State University in University Park. Beatty is the lead researcher on the team.
“Hot Jupiters provide us with the best views of what climates on other worlds are like. Understanding the atmospheres on these planets and how they work, which is not understood in detail, will help us when we study these smaller planets that are harder to see and have more complicated features in their atmospheres.”
Though the titanium oxide precipitation has been theorized before, this is the first time it has been observed.