Astronomy is one of those branches of science that is exciting to study. Every time we look up into the night sky and dream about the stars or look at a picture of a crater and wonder how it got there, we are learning about astronomy. These simple experiments are only the beginning of the fun you can have with astronomy. You don't even need a telescope to learn new ideas and have some fun.
METEORITES AND CRATERS
Craters are round bowl shaped depressions surrounded by a ring that are made when a meteorite collides with a planet or moon. If you look at our moon, the round holes that make it look like Swiss cheese are craters. There are pictures on the Internet of a place in Arizona called Meteorite crater, where a meteorite crashed into Earth about 50,000 years ago leaving a crater of a mile across. Most craters are only fist-sized.
In this experiment, you will investigate how different sizes and speeds of meteorites create different shaped craters. Make a meteor landing area by emptying a pound of white flour into a cardboard box to about 1 inches (3-4 cm) thick. Sprinkle a light dusting of cocoa powder over the top to make the crater more visible. Gather various sized pebbles. These are your meteorites.
Drop one of the smallest pebbles from about eye level into the landing area. Describe what you observe about the size and shape of the crater in your science notebook or data sheet. Next drop a medium sized pebble from the same height. What is different about the crater? Now drop the largest pebble from the same height and predict what you will see.
Next, find pebbles that are about the same size. Smooth out the flour and add a little more cocoa. First have the shortest person drop the pebble from eye level and record what you observe about the crater. Then have the next taller person drop a pebble from eye level and finally the tallest person drop a pebble. Make sure all the pebbles are dropped vertically for consistency in the test. Try to predict the appearance of a crater formed by pebbles of the same size dropped from different heights. What do you think accounts for the difference?
Now test for the angle of impact. What do you predict about the different shapes of craters when the meteorites strike from different angles? Smooth the flour again and sprinkle more cocoa. Now throw a medium sized pebble vertically into the flour. What will happen if you throw a pebble of about the same size and the same amount of force vertically into the flour? The next person should throw a pebble of similar size and about the same speed but this time at a slight angle. Continue throwing pebbles of about the same size and speed, but at different angles of trajectory. Document your observations on a data sheet. Are all the craters circular? You might be surprised by the results.
MAKE A SUN CLOCK
We can use the movement of the sun to tell time, just as people did before they had clocks. Take a piece of cardboard, 4 inches square (10 cm) and cut a 1 inch (2 cm) hole in the center of the square. Tape the square onto a sunny window. Place it so that the sunlight shining through the hold makes a spot on the floor. Place a piece of paper on the floor so that the spot of sunlight lands on the paper. Draw a circle around the spot of light and write the time next to it. Continue to mark the sunlight spots every 30 minutes. Use more paper and record the times and movements as you watch the spot of sunlight move from left to right and change positions as time changes.
The earth rotates, or turns, from east to west every 24 hours as it rotates around the sun. This movement of the earth causes the spot of sunlight to move across one paper and to the next as the earth moves from sunrise to sunset.
If you like long-term experiments and you have a room with a south facing window where your paper can sit undisturbed through changing seasons, try this. Take several smaller pieces of paper and mark the spot on the floor at a certain time of day on different days throughout the year. For example, place a piece of paper under the spot on the floor at 8:00 am on June 21, 8:00 am on July 30 and again at 8:00 am on September 21.
MAKE A SHOEBOX PLANETARIUM
Research constellations and find your favorite. Some of the names might be familiar because they are the names of the zodiac, like Taurus or Capricorn. You might even want to read a little of the mythology that goes along with your constellation.
You will need a shoebox, black construction paper, tracing paper, a compass or other sharp point, scissors, penny, ruler, and tape.
Using a ruler, find the center of one end of the box. Trace the penny and cut out the circle to make the viewer. Put the lid back on the box and trace a rectangle on the other end of the box where the lid meets the side, and 2 cm along each side and 2 cm from the bottom. Cut out the rectangle.
Cut the black construction paper so that it will fit over the rectangle. Use tracing paper to copy the constellation. Lay the tracing paper over the black paper and use the sharp point of the compass to poke holes through the tracing paper and the black paper. Make larger holes for brighter stars and smaller holes for dimmer stars.
If this is a classroom project, you can trace your constellation onto an index card; write the name on the card, and tape it to the inside lid of the box. Take turns with other students looking through the viewer and guessing the name of the constellations.
Learning about astronomy is a great way to get kids interested in science, and parents will learn some interesting facts right along with them. Have fun studying the stars together.