Student Features

How the Saturn Spacecraft Got Their Names
06.24.04
Cartoon image of Cassini and Huygens standing in front of history books
The two explorers going to Saturn have interesting names. Where did the names come from? Each of the spacecraft is named after someone who played an important part in learning more about Saturn.

Huygens (pronounced HOY gunz) is really a probe. When the time is right, it will separate from the Cassini spacecraft. Huygens will then drop down to explore Titan, Saturn's largest moon. Huygens will send back lots of valuable information about Titan to scientists on Earth.

Image to left: Cassini and Huygens are named for astronomers who studied Saturn's rings. Credit: NASA/JPL

In the early 1600s, the astronomer Galileo studied Saturn. He used his homemade telescope. Around 1610, he noticed something odd about the planet's shape. It seemed to Galileo that Saturn was not one planet, but three. He decided that Saturn must have two large moons, one on each side. And it seemed that they didn't orbit. Somehow, the moons just stayed stuck to the planet's sides.
 
A few years later, Galileo couldn't see anything around Saturn.

Image to right: Hold your mouse over the drawing to see Galileo animated.
Credit: NASA/JPL


Later, a Dutch astronomer made better telescopes than the ones Galileo had. His name was Christiaan Huygens. Using the telescopes, he figured out that Saturn must have a detached, wide, thin ring. Huygens made drawings showing how Saturn could change its appearance because of the rings. He also showed how the rings could seem to disappear every few years.
 
Huygens also discovered Saturn's largest moon, Titan. This is the moon that the probe is going to explore. That's why the probe is named Huygens.

An Italian-French astronomer was also studying Saturn. His name was Giovanni Cassini. He is also known as Jean Dominique Cassini. He watched the planet so much that he noticed a space inside the rings. He discovered there were actually two main rings. This gap between them is still called the "Cassini Division."

Image to left: Hold your mouse over the drawing to see Christiaan Huygens animated. Credit: NASA/JPL


 
Cassini also guessed that the rings were actually made up of rocks or "moonlets" too small to be seen individually. And he was right. We now know that there are many rings. The rings are all composed of tiny particles and even some small moons. So the spacecraft was named Cassini in honor of the astronomer.

Image to right: Hold your mouse over the drawing to see Giovanni Cassini animated. Credit: NASA/JPL
 
Adapted from Historical Fun Facts