Out of This World Names

Want to visit Dorothy Crater? You won’t find it in Kansas. It’s on Charon, Pluto’s largest moon. Dorothy Crater is one of 12 features on Charon that received official names earlier this year.

The International Astronomical Union (IAU) approves all names for features like mountains, canyons, and more on objects in our solar system. Each planet or moon has a theme. Features on Mars and the moon honor scientists and writers. The features on Venus are named after notable women. Jupiter’s moon Io showcases gods and goddesses from around the world.

Want to visit Dorothy Crater? Despite the name, it's not in Kansas. It's on Charon. That's Pluto's largest moon. Dorothy Crater got its name earlier this year. So did 12 other features on Charon.

Scientists name features like mountains and canyons on other moons or planets. The International Astronomical Union (IAU) approves all the names. The names for each place have a theme. Features on Mars and the moon honor scientists and writers. On Venus they're named after women. Features on Jupiter's moon Io aren't named for people. Instead, they showcase gods and goddesses from around the world.

The New Horizons spacecraft flew by Pluto and its moons in 2015, snapping pictures. The IAU worked with New Horizon’s scientists to decide Charon’s themes. “Because it’s a new extreme distance for planetary exploration, the theme honors the memory and literature of exploration,” says Mark Showalter, a New Horizons scientist.

Exploration wasn’t the only theme they considered. Charon’s montes were almost named for animals that live in the dark! Deciding the themes is a fun break from Showalter’s typical routine. “Science isn’t all about equations,” he says. “Naming things is one of the bridges between the scientific world and our culture and history.”

The New Horizons spacecraft flew by Pluto in 2015. It took pictures of Charon and other moons. The IAU worked with New Horizons scientists to decide how to name things on Charon. Because Pluto is so far from Earth, they picked a theme of exploration, says Mark Showalter. He's a New Horizons scientist.

Exploration wasn't the only theme they thought about. Charon's mountains were almost named for animals that live in the dark! Naming features is a fun break from Showalter's typical work. "Science isn't all about equations," he says. "Naming things is one of the bridges between the scientific world and our culture and history."

The charts below show the features and name themes of select astronomical objects. Use them to answer the questions. Write all answers in simplest form. Record your work and answers on our answer sheet.

What is the ratio of the craters on Charon to its total number of features? What type of ratio is this?

What is the ratio of features named for ships on Charon to features named for ships on Mercury?

A. All three astronomical objects in the charts have craters. What’s the ratio comparing the number of craters on Pluto to the total number of craters?

B. Write a ratio comparing the number of craters on Charon to the number of craters on Pluto. What type of ratio is this?

A. What’s the ratio of features on Charon named for fictional explorers to features named for fictional ships?

B. Write a ratio comparing the features named for fictional and historical explorers to the total number of features on all three astronomical objects.

A. What’s the ratio of the total number of features on all three objects named for real people to the number of features on Pluto named for real people?