8 Dry Ice Snow
Mars has some serious snowstorms that occur during the middle of the night.
Our neighboring planet has clouds of water and ice that are extremely low, merely 1 or 2 kilometers (0.6–1.2 mi) above the surface of the planet. It was previously believed that precipitation from these clouds would drift lazily toward the planet’s surface, taking hours or days to reach the ground. Information gathered by the Mars Global Surveyor and the Mars Reconnaissance Orbiter proved otherwise. Martian snowfall can reach the surface of the planet in less than ten minutes.
The temperature drops considerably when the Sun sets on Mars, and vigorous winds create a blizzard-like snowstorm. These nighttime storms are referred to as “ice microbursts” and are comparable to small, localized storms that occur on Earth.
Some of the snowstorms on Mars are made of dry ice, specifically those near its south pole. Clouds form from frozen carbon dioxide. Flakes from these clouds fall thickly enough to accumulate, contributing to the carbon dioxide ice cap that covers the planet’s south pole.
7 Gemstone Rain
HAT-P-7b is an exoplanet located 1,000 light-years from Earth. The planet is 40 percent larger than Jupiter and orbits a star twice as large as our Sun. HAT-P-7b is very close to its massive star and tidally locked. The sun-facing side of the planet experiences average temperatures of 2,586 degrees Celsius (4,687°F). The dark side of HAT-P-7b is drastically cooler, and the difference in temperature between the two sides creates intense winds that circle the planet.
Clouds form on the cooler dark side of HAT-P-7b. Strong gusts blow the clouds over to the sun-facing side, although these clouds do not last long on the dayside of the planet before vaporizing in the extreme heat.
HAT-P-7b’s clouds are beautiful. They contain corundum, the mineral that produces sapphires and rubies on Earth. Rain from corundum clouds is undoubtedly dazzling as well, but astronomers must learn more about HAT-P-7b’s atmosphere in order to determine how corundum precipitation appears when reacting with other chemical compounds on its way to the planet’s surface.