Amanda Maxwell

Dec 3rd 2019

Raining Diamonds on Saturn, and Other Stories of Weather in Space


The weather outside might be frightful, but have you ever wondered about the weather in space? Since other planets have different atmospheres than Earth, weather conditions aren’t necessarily the same on each planet.

Solar System-Wide Weather

System-wide weather exists in the form of solar storms; waves of electromagnetic particles blast off from the sun’s surface as solar flares and coronal mass ejections. The effects range from widespread power outages to interference with the radiocommunications, as well as impressive light shows like the auroras or polar lights over the poles.

NASA invests heavily in space weather technology like satellites and low Earth orbiting systems to monitor impact on our own climate. The agency is also keeping tabs on weather across our solar system and beyond, with findings that could be useful to life here on Earth.

Windy Outlook on Mars

Weather tech here on Earth helps predict extreme weather scenarios, like shifting polar vortex impact on cold weather outflow. It also helps outpace storms for proactive response to prevent damage. Our storms are localized to specific areas on Earth, but the entirety of Mars can be enveloped in a dust storm. On Jupiter, NASA has found cyclones that cover most of the planet. Storms also last a long time in space; the biggest storm on Jupiter — visible as the Great Red Spot to astronomers — has been active for hundreds of years. On Uranus, IFL Science describes how infrared telescopes track giant hurricanes across the planet.

Martian winds form due to the difference in air temperatures between hot and cold surfaces; the planet’s sandy surface gains and loses heat rapidly to drive air movement, but the atmosphere lacks moisture and is much thinner than Earth’s. Although it’s easier to whip up a planet-wide dust storm, wind speeds measured by the various Mars rovers are not as great as on Earth. Despite the lack of power, Space notes that Martian dust is electromagnetically charged; in addition to “sticky” particles obscuring solar panels powering planetary rovers, storms wreak havoc on sensitive electronics.

Raining Diamonds on Saturn

Conditions on other planets are not the same as on Earth. Planets such as Venus and Jupiter lack our atmosphere rich in nitrogen and oxygen, and there is no moisture to drive a lifegiving water cycle. It shouldn’t be surprising that the weather in space also differs; something as simple as rain might not be the same wet stuff we’re used to here on Earth.

For example, according to a report in Nature, scientists believe it could be raining diamonds on Jupiter, Saturn and Uranus.

Based on observations by interplanetary spacecraft like Cassini, researchers theorized that lightning could split carbon atoms from atmospheric methane, forming soot, which would then create diamond or graphite under combinations of high pressure, heat and then rapid cooling. Saturn’s intense atmospheric pressure squeezes carbon into diamond or graphite projectiles that zip around like bullets in the wind. These extremes could also create diamond oceans on Neptune.

This might also be happening outside our solar system. Gizmodo reports that it could be raining gemstones on exoplanet HAT-P-7b. The Kepler space telescope spotted changes in brightness that could signify rubies and sapphires squeezing from the corundum-containing clouds circling the far-off world.

Acid Rain on Venus and Dry Ice Snow on Mars

Pollution causes acid rain on Earth; on Venus, it happens naturally as sunlight splits sulfur dioxide in the atmosphere, according to research from the European Space Agency Venus Express probe. However, the Venusian atmosphere comprises a thick blanket of carbon dioxide that prevents heat from the sun escaping, so the acid rain drops evaporate long before they hit the planet’s surface.

Methane rains on Saturn’s moon Titan, according to Astronomy. Over the polar regions on Mars, snow falls as dry ice or solid carbon dioxide since the atmosphere is largely devoid of water vapor.

What We Can Learn From Weather in Space

So why bother with weather forecasts on other planets? Is it worth knowing about the vertical double eye of the northern polar vortex on Venus? The answer is that this kind of data can help with life on Earth, especially in the face of climate change.

Weather on Mars, for example could help scientists understand vulnerabilities in the water cycle here on Earth. Research has shown that Mars once held surface water. A report in Nature on the ExoMars Trace Gas Orbiter describes how dust storms transport water vapor into the escape region of the upper atmosphere.

Gathering planetary weather data for modeling could help the search for other worlds capable of sustaining life. A report from the NASA Goddard Space Institute mentioned in Science Alert proposes that Venus might have been habitable at one point. Virtual modeling suggests that although its current climate causes an intense greenhouse effect, the planet might have been habitable for around 3 billion years. This could re-direct searches for Earth-like exoplanets into regions around stars previously discounted.

Farther from home, New Atlas reports on climate data modeling for the TRAPPIST-1 exoplanet system of Earth-like planets circling a red dwarf star. This kind of research can help space telescopes such as the James Webb Space Telescope pick out habitability signals across space and perhaps direct interplanetary travel in the future.