‘Jupiter and Juno’

The ancient Romans made up stories about gods and goddesses. These stories are called myths.

According to one ancient Roman myth, Jupiter was the top god. He had two brothers and three sisters. The three boys got to divide up the world, with Jupiter getting the sky, Neptune getting the ocean and Pluto getting the underworld. Jupiter was powerful, and he really liked to throw his weight around. He hurled lightning bolts, created booming thunder and cloudbursts of rain, and generally made the other gods nervous. Jupiter wasn’t afraid of anything — except his wife, Juno.

Juno was a jealous wife. And Jupiter, when he got bored, liked to get into mischief. To hide his mischief from Juno, Jupiter covered the world in clouds, thinking she couldn’t find out what he was really up to. But Juno was very smart, and became suspicious about what might be going on under all those clouds. When she found out about her husband’s misdeeds, Jupiter was in trouble. And the story goes on and on, and the characters do not necessarily live happily ever after.

The ancient Romans even named the planets after gods. Some thought the planets actually were gods. The planets they could see they named Mercury, Venus, Mars, Saturn and Jupiter.

Just as Jupiter was the chief Roman god, Jupiter is our solar system’s largest planet — by far. It contains twice as much matter as all the other planets combined. It’s also quite stunning, with its orange, yellow, and white bands and its huge red spot — a storm big enough to swallow Earth!

When we look at the planet Jupiter, we are seeing only the very tops of the clouds. And as with the Roman god Jupiter, what’s going on beneath the clouds is a big mystery. One thing we do know is that Jupiter is a gas planet. You could not set foot on Jupiter even if you wanted to — which you wouldn’t!

But if Jupiter is mostly gas, how can it be shaped like a ball or sphere? It’s because of gravity. Jupiter is so massive that the force of gravity has pulled all its material in as close and tight as possible. That’s what makes it round — and very, very dense deep inside.

Jupiter’s atmosphere is mostly hydrogen and helium. And if you could dive down through the gas, you would encounter some very bizarre materials indeed. Scientists think the depths of Jupiter could contain a liquid form of hydrogen that conducts electricity like a metal!

Spacecraft have visited and studied Jupiter before. Voyagers 1 and 2 flew past Jupiter in 1979, and Galileo orbited and studied Jupiter and its moons from 1995 to 2003. Even so, the giant planet still holds many mysteries. What is its atmosphere made of? How is everything arranged on the inside? How deep is the red spot? How does Jupiter’s powerful magnetic field work? What is it hiding?

The Juno mission will try to answer these questions. On Aug. 5, NASA launched the Juno mission to Jupiter. The spacecraft will arrive at Jupiter in July 2016. It will orbit close to Jupiter’s north and south poles, coming closer to Jupiter than any spacecraft before. Like its namesake, the goddess Juno, this spacecraft has special abilities that allow it to peer through Jupiter’s clouds to see what’s going on beneath. It will map and measure many different characteristics of Jupiter that will help scientists unravel its true nature.

Play JunoQuest at the Space Place, and fly Juno close over Jupiter. Help Juno fulfill its exciting mission. Visit spaceplace.nasa.gov/junoquest.

This article was provided courtesy of the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

For more Kids’ Reading Room, visit latimes.com/kids. Diane Fisher of JPL has written many articles for The Kids’ Reading Room. To see a sampling of those stories, visit Short Stories in Activity Center.