Make a football-sized model of the solar system, using
an orange for the sun. Place it on one goal line.
Using a scale of 1 yard to 10 million miles, Mercury
would be about halfway between the 3- and 4-yard lines.
Now determine the position of the other planets. (Note:
Although the yard lines on a football field go from
0 to 50 and back to 0, treat them as 100 continuous
Catch Some Rays.
Grab some sun on a cloudy day with a thin piece of
cardboard, a sheet of white paper, a pen, and the
help of a friend. Punch a hole in the cardboard with
the tip of the pen. While your friend holds the cardboard
in direct sunlight, hold the paper in the cardboard's
shadow. Look for a small, white circle?it's
an upside-down image of the sun! Focus the image by
moving the cardboard forward or back. When a cloud
passes in front of the sun, you'll see the cloud's
shadow cross the your sun image in the opposite direction.
Remember: Never look directly at the sun!
Here's a sweet way to learn more about the mountains
on Venus and Mars. Gather Hershey Kisses? or
other chocolate candies. To represent Mars, freeze
a few of then on a plate. Set others on a plate in
direct sunlight to represent Venus. For Earth, leave
a third batch at room temperature. Check back later,
and put your mini-mountains to the test by answering
these four questions: Are they all the same "altitude"
(height)? Have any changed shape? What other differences
do you see? What happens when you tilt the plates?
A Fine Mess.
Pretend a scientist has discovered that a killer asteroid
will hit the Earth in a matter of weeks, but no one
knows exactly where. What would you do if you were
in charge of preparing the world for the impact? Create
a three-part plan to divert the space rock, lessen
its impact, and save as many lives as possible.
Scope It Out.
Galileo's telescope was advanced for its time, but
primitive compared to what we have today. Circling
in space is the Hubble Space Telescope. Log onto its
Web site at http://oposite.stsci.edu/pubinfo/pictures.html and view close-ups of the planets and stars. Research
the subject of your favorite photo, and write a report
about what new information the Hubble photographs
have given scientists.
Pretend you're on spring break and your family decides
to head to Venus. What would you like to do there?
What would it be like? What would you have to bring?
Soak in the Venusian facts in this book and other
references. Then write a detailed travelogue for your
friends back home.
It Weighs What?
Jupiter is only about one-fourth as dense as Earth,
but it's 300 times as heavy. If it were as dense,
it would be 1,200 times as heavy. Get a feel for how
the weight of a hollow object varies when filled with
different substances. Take two uninflated beach balls
the same size. Weigh them to make sure they're the
same. Cut a small slit in each one. Fill one with
water, close the slit with sealing tape, and weigh
it. Subtract the ball's weight from the weight of
the water. Now fill the other ball with substances
such as sand and shredded paper. Compare the density
of these substances to the water.
Hello Again, Halley!
Halley's comet zooms by Earth regularly, about every
76 years. Reports from ancient China indicate that
stargazers saw it in 240 B.C. The comet made its most
recent an appearance in 1986. Pretend Halley's comet
has returned. How old will you be? What will your
life be like? Make a mockup of the front page of a
newspaper that might be published on the day Halley's