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Europa

More than 60 moons orbit Jupiter. One of these moons is Europa. It is especially intriguing to scientists. Miles below its cracked icy surface lies a deep saltwater ocean. Future missions to Europa will investigate these oceans for signs of life. If life exists, what kinds of organisms could survive in such a cold, dark place? To answer this question, scientists look to some of the most extreme environments on Earth.

Stats

Description: one of Jupiter's largest moons; entirely covered by a thick icy ocean
Discovered By: Galileo Galilei in 1610
Size: 1,940 miles (3,122 km) in diameter
Average Distance from the Sun:
778,340,821 kilometers (483,638,564 miles)
Average Surface Temperature: -162°C (-260°F )
Cool Fact: One day, a robot may study Europa's oceans. Today, these robots are being tested under the ice of Antarctica.

Stumper

Engineers are developing a robot that may someday explore Europa's deep, dark oceans. Besides navigating underwater, it would:

fly

melt ice

carry astronauts

Correct!

A spacecraft would carry the robot to Europa's surface. There, the robot's nuclear-powered generator would melt through miles of ice to get at the ocean underneath. Then, instruments could measure the chemistry and composition of the water. Would we discover life on Europa?

Stumper

To get a sense for possible life on Europa, scientists look to extreme organisms that live in Earth's:

coral reefs

Arctic oceans

deep sea

Correct!

Organisms that have adapted to harsh environments, like the extreme coldness and darkness of the deep sea, are called "extremophiles." If extremophiles can survive on Earth's deep sea floor, there might also be life in Europa's deep, dark sea.

Fact or Fiction

Europa is about 10 times the size of Earth's Moon.

Fact

Fiction

Europa is slightly smaller than our moon. Interestingly, Jupiter's diameter is more than 10 times Earth's.

Fact or Fiction

From Europa, the Sun looks similar to other stars in a never-ending night sky.

Fact

Fiction

Fact

The further away you are from a star, the smaller it looks. And Europa is five times further away from the Sun than Earth is from the Sun.

Image credits: main image, NASA.

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