The Search for Extraterrestrial Life

Are we alone in the universe? This is one of the biggest questions in science. Scientists are looking for life beyond Earth in many ways. They search for tiny organisms on planets and moons in our solar system. They also listen for signals from intelligent life far away in the galaxy.

Where to Look

Scientists think the best places to find life in our solar system are Mars, Europa, and Enceladus. Mars may have had water and life long ago. Europa and Enceladus have oceans of liquid water hidden under ice. Water is important because all life on Earth needs water. Scientists also look at exoplanets that might have the right conditions for life.

Listening for Signals

A project called SETI uses giant radio telescopes to listen for signals from intelligent aliens. So far, no signal has been found. Scientists also look for signs of chemicals in the atmospheres of distant planets that might be made by living things. The search has been going on for decades, and scientists keep improving their tools.

Fun Facts

• Scientists have found over 5,000 planets orbiting other stars, and some may have conditions for life.
• The SETI project has been listening for alien signals since 1960.
• Some scientists think there could be life on Titan, one of Saturn's moons, but it would be very different from life on Earth.

Did You Know?

In 1977, a SETI radio telescope picked up a strong, unusual signal from space that lasted 72 seconds. It was called the Wow! Signal, and scientists still do not know what caused it.