Weather on Other Worlds
Do other planets have weather like Earth?
What do the swirling clouds near Jupiter’s poles look like?
What is a vortex?
What is turbulence, in air or water?
What’s the difference between a cyclone and an anticyclone?
What is a “front” in the ocean?
How do dust storms form, on Earth or on Mars?
How many weather stations are there on Mars?
What’s special about Titan, one of Saturn’s moons?
On Earth, water vapor creates clouds. What kind of vapor forms clouds on Titan?
Skies Far Away
You might think weather only happens here on Earth. But if you look at clouds on other planets, you might be surprised.
The swirling clouds near Jupiter’s poles look a lot like ocean currents here on Earth.
Dust storms on Mars and rainstorms on Titan (one of Saturn’s moons) also look strangely familiar.
Even though these places are very far away—millions of miles from Earth—they follow the same basic rules of science.
Scientists have been using weather models based on Earth to understand the skies on other planets. These models use the same kinds of math and science but are adjusted to fit each planet’s gravity, spin, and atmosphere. Because we know a lot about weather here, scientists can use that knowledge to figure out what’s happening far away in space.
According to scientist Scot Rafkin, studying weather on other planets also helps us learn more about our own planet.
Storms on Jupiter
Jupiter is a gas giant with wild weather.
When scientists first saw images of the clouds at its poles, they noticed something strange. The patterns looked a lot like the swirling water in Earth’s oceans.
One scientist, Lia Siegelman, said it reminded her of turbulence. (You may have experienced turbulence when flying in an airplane).
Turbulence —chaotic movement—is also seen in ocean currents.
Siegelman worked with other scientists to study Jupiter’s weather.
They found that the rules that control moving air or water on Earth also work on Jupiter. Even though the vortexes (spinning storms) on Jupiter are about ten times larger than ones on Earth, they behave in similar ways.
One exciting discovery was that cyclones (which spin one way) and anticyclones (which spin the opposite way) on Jupiter created swirling patterns that looked like fronts in Earth’s oceans.
On Earth, these fronts mark where different water masses meet.
Siegelman and her team also noticed something never seen on Earth: a pattern of cyclones in a perfect, repeating shape near Jupiter’s poles.
These “polar vortex crystals” have stayed in place since they were first seen in 2016. Even though Earth has nothing like them, scientists could recreate these patterns in computer models using simple physics.
By understanding how Earth’s air and oceans move, scientists are getting better at understanding what’s happening in Jupiter’s atmosphere.
Dust Storms on Mars
If humans ever move to Mars, they’ll need to be ready for dust storms.
These storms can cover the whole planet and last for days or even months. The dust blocks sunlight and coats everything. Scientists have seen many of these storms, but they still can’t predict when they’ll happen.
Dust storms on Mars begin in a way that’s similar to Earth. Warm air rises, pulling in more air from below. This moving air lifts up dust from the ground.
As Mars spins, the dust storms can start to rotate. This is like what happens during hurricanes on Earth.
Claire Newman, another scientist, explained that while Mars is a dry, dusty planet and Earth is a wet, watery one, both planets have storms that affect temperature and wind in similar ways.
Still, scientists don’t fully understand how Martian dust storms get started. Some storms begin when a cold front moves in—just like on Earth. But other times, dust storms seem to appear out of nowhere.
To predict storms on Mars, scientists need to learn more about how air moves there.
Unlike Earth, Mars doesn’t have many weather stations. Most of what we know about its air movement comes from computer models. These models use Earth-based ideas but are changed to fit Mars.
Rafkin said that until we have more tools on Mars, computer models are our best chance to understand these storms. Newman added that it’s important to understand the Martian environment before sending robots—or even people—there.
Rain on Titan
Titan is Saturn’s second-largest moon.
It’s the only other place we know of with rivers, lakes, and seas on its surface.
But these lakes aren’t made of water—they’re made of liquid methane. That might sound strange, but Titan’s weather has a lot in common with Earth’s.
Rafkin said that the way it rains on Titan is similar to how it rains here.
On Earth, warm air full of water vapor cools down. When it cools enough, clouds form. Tiny drops inside the clouds grow until they’re heavy enough to fall as rain.
The same thing seems to happen on Titan, except it’s methane vapor, not water vapor. Scientists have only visited Titan’s atmosphere a few times, so they rely on models to figure out what’s going on. These models use Earth’s weather science as a starting point.
When scientists modeled clouds on Titan, the clouds looked similar to the few real ones they’ve seen. That tells them their models are probably on the right track.
Titan has a very thick atmosphere, so its storm clouds are two to four times taller than Earth’s. These clouds can drop a lot of methane rain—enough to soak the ground. Scientists haven’t seen this much rain happen yet, but they have seen the ground darken, which suggests rain has fallen.
No one knows exactly where all the methane comes from. But if we ever visit Titan, we’ll need very strong raincoats.
Atmosphere – The layer of gases around a planet or moon.
Model – A scientific tool used to understand or predict how something works.
Gravity – The force that pulls things toward the surface of a planet.
Turbulence – Chaotic, swirling motion of air or water.
Vortex – A spinning, swirling movement of air or liquid.
Cyclone – A type of storm that spins in a circle.
Anticyclone – A storm that spins the opposite direction of a cyclone.
Front – The place where two different air or water masses meet.
Symmetrical – The same on both sides or in a pattern.
Deluge – A large amount of rain or liquid falling in a short time.
Methane – A gas that can turn into liquid at very cold temperatures.
Condense – To change from a gas into a liquid.
Precipitation – Rain, snow, or any form of water falling from the sky.
Forecast – To predict what will happen in the future, especially weather.
Angular momentum – A scientific term describing how things spin.
► COMPREHENSION QUESTIONS
— please answer with complete sentences
Do other planets have weather like Earth?
What do the swirling clouds near Jupiter’s poles look like?
What is a vortex?
What is turbulence, in air or water?
What’s the difference between a cyclone and an anticyclone?
What is a “front” in the ocean?
How do dust storms form, on Earth or on Mars?
How many weather stations are there on Mars?
What’s special about Titan, one of Saturn’s moons?
On Earth, water vapor creates clouds. What kind of vapor forms clouds on Titan?
► From EITHER/OR ► BOTH/AND
► FROM Right/Wrong ► Creative Combination
THESIS — Argue the case that weather on other planets can’t possibly be like weather on Earth, just look at Titan with methane vapor instead of water vapor!
ANT-THESIS — Argue the case that weather on other planets is very, very similar to weather on Earth.
SYN-THESIS — How might both perspectives be correct at the same time?
