What you need:
A big piece of poster board measuring about 18 x 24 inches
What to do:
This project is very simple. Roll the poster board into a cone shape, leaving a small hole at the end about ½ inch wide. Then tape the board into place.
Take your cone outside and put your ear up to the small end. Point the big end of the cone in various directions and notice all the different sounds you hear.
What type of noises did you hear with the cone that you were not able to hear without it?
Can you guess how this type of device helps scientists hear noises from space?
Like waves in the ocean, sound makes waves in the air. Air jostles back and forth as the sound energy waves pass. If you put something like paper in the path of the sound wave, it will also vibrate quite a lot. If you give this paper surface the right shape, the sound waves will be funneled to a point. So your super sound cone is a sound funnel!
Of course, no spacecraft actually communicates by sound. Messages wouldn't get very far, since sound waves can't travel in the vacuum of space! But the spacecraft do send out radio waves, which can travel practically forever. The trouble is, the radio waves spread out and get weaker and weaker the farther they travel.
So NASA's radio wave "ears" must be very big indeed!
Courtesy: Space Place