Phone Calls to Outer Space

Have you ever wondered what it would be like to talk to somebody or something that is from out of this world? The people at SETI (Search for Extra-Terrestrial Intelligence) have a lot of people who are willing to help them look for aliens. Astronomers with huge radio telescopes receive signals from the stars in space all the time, but the scientists at SETI are searching for signals that change, similar to a code you might use to talk to a friend. Over the years, many people have volunteered to help search for these unusual signals. The SETI project connected these people's home computers through the Internet to check out and sort the information the telescopes obtain. Do you think these astronomers are searching the skies to communicate with other people in the solar system, since extraterrestrial means not of this Earth? Or do you think they are hoping to visit with an alien from outer space? Even if SETI eventually receives any signals, the one trying to communicate will probably no longer exist.


It's All Elementary

All of the elements on Earth, some of which must be manufactured in a laboratory, can be found in the radiation from stars measured by the spectroscopesor cameras mounted on telescopes. They are all formed when stars die.

Collect Call

An astronomer at SETI has just received the very first message from outer space! He tried to email the news to his friends, but in his excitement, the astronomer put his hands on the keyboard in the wrong position. Now the message looks like a bunch of jibberish! Use the keyboard below to decode the message.

It takes a long time for light and radio waves to travel any distance in space. SETI is hoping another friendly being from the distant galaxy will still be waiting for a return phone call from Earth!

Speed of Sound

Do you like thunderstorms? Most of the time a flash of lightning is followed by a loud clap of thunder unless the storm is too far away. Sometimes all you see is the light flickering in the distance, which is also known as heat lightning. If you count 1,001, 1,002, etc. between the flash and the boom, you can estimate how far away the storm is. So why does it take longer to hear the thunder? Sound travels through the atmosphere at about 1,000 feet per second while light travels at 186,000 miles per second. It is pretty easy to guess which one will get there first. Strange as it may seem, the temperature of the air and how high up in the atmosphere the sound is will also affect how fast it travels.

Can Sound Get Wet?

Do you think sound travels faster or slower in water? If you want to find out, have one of your parents stand at one end of your local swimming pool while you make a noise in the air above and below the water at the other end. Which one of the sounds traveled faster? If you lived in space, you wouldn't be able to hear any noise at all because sound waves can't travel where there is no atmosphere. As a rocket leaves the atmosphere, do you think it would sound more like someone turning the volume down on a radio or do you think the sound would just slowly fade away? The lack of sound in space was a big problem for the astronauts who were trying to communicate when they went out there. To solve the problem scientists installed radios in the space suits of the astronauts so they could talk to each other and to their mission control center hear on Earth.


Beings thought to live somewhere else out in space are called aliens.

No one is sure if there is any other life in the universe, other than here on Earth. Another name for an alien is an extraterrestrial.


Upside-Down Stars

Most telescopes see stars upside down, unlike binoculars. Telescopes come in all shapes and sizes. Some are so big that the astronomers have to travel up the telescope to reach the eyepiece at the top.

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