The Children's Encyclopedia of
Science
COMETS, METEORS, AND ASTEROIDS
Activities
1. Spot a meteor
You can see meteors, or shooting stars, on any clear night of the year. It's best
to look for them when you are well away from bright city lights. Simply stare
upwards for a few minutes, and you should see the thin white trail of a meteor
flash across the sky. If you're patient, you may see as many as 10 meteors an
hour.
On certain nights of the year, there are meteor showers. Each one is named after
the constellation of stars from which it seems to come.
Try to spot the meteor showers listed below. To get help in locating them, visit
a planetarium or refer to a book on the sky at night.
Shower |
Dates |
Best night |
Quadrantids |
Jan.1 - Jan. 6 |
Jan. 3 |
Perseids |
Jul. 25 - Aug. 18 |
Aug. 12 |
Orionids |
Oct. 16 - Oct. 26 |
Oct. 21 |
Taurids |
Oct. 20 - Nov. 25 |
Nov. 4 |
Geminids |
Dec. 7- Dec. 15 |
Dec. 14 |
2. Draw the path of a comet
Comets move in very long, stretched out orbits around the Sun. The shape of the
paths is an oval, or ELLIPSE.
To draw an ellipse, begin by taping a big sheet of drawing paper onto a flat wooden
board. Press two thumbtacks, three inches apart, halfway into the board and paper.
Cut a piece of strong thread about a foot long and together its ends.
Next, loop the thread around the pins and stretch it tight with a pencil. Keep
the pencil upright and the thread tight, and move the pencil around the whole
loop. The shape you'll have drawn is an ellipse.
Try changing the distance between the pins. Try smaller distances – one
or two inches – and larger distances – four or five inches. What do
you notice? Which look more like the almost circular paths of planets? Which look
more like the long, narrow paths of comets?
3. Make craters
Investigate how craters form. Spread newspaper on the floor. Put about 3 inches
of flour in a shallow box, such as a shoe box. Sprinkle chocolate cake mix or
paint powder on top of the flour using a sieve to get an even layer. Choose several
small objects of different size and weight to represent your meteorites. Marbles
and pebbles work fine. Drop each object from a height of three feet. After each
drop, measure the size of the crater formed, make notes on what the crater and
surroundings look like, remove the fallen object, and smooth over the flour. Experiment
by dropping the objects from different heights and throwing them in a different
angles. Does the angle affect the shape of the crater produced? Investigate features
such as crater walls, central peaks, and rays.
Crater glossary
Central peak – A mountain found in the center of large craters. It
is formed by a rebound of molten rock at the impact site (the marble will be sitting
there in this activity).
Crater – A (usually) circular depression in a surface caused by an
impact.
Ejecta – Material thrown out of the crater.
Ejecta blanket – Ejecta tossed out at low speed. The material lies
like a blanket around the crater.
Floor – The interior of the crater.
Rays – Ejecta thrown out of the crater at high speed. The material
forms long lines pointing directly away from the crater.
Rim – The raised edge of the crater. It is formed by the outwards
and upwards compression of the crater walls, not ejecta.