Sun, Moon, and Stars: Astronomy for Beginners · Part II, Ch. X · Part 2: Part II: A closer look at the Solar System
23. Comets and meteors: family ties
Goal: Your child can explain that meteor showers come from the paths of comets, and why the Earth meets the same shower each year.
You'll need
- The book, open to Part II, Chapter X
- A hula hoop or a circle of rope on the floor
- A handful of uncooked rice or birdseed
What's in the book
A surprising discovery: comets and streams of meteors travel along the same orbits. The chapter describes the August and November (Leonid) meteor rings, the great November display of 1866, and the idea that the Solar System may hold countless meteor streams, using a blind man feeling rain to picture it.
The lesson, step by step
Read together
Read the chapter aloud. At the 1866 shower, stop: eight thousand meteors in two and a quarter hours were counted at Greenwich.
Walk through a meteor stream
Lay the hoop on the floor: that is the Earth's orbit. Sprinkle a line of rice across one part of the hoop: that is the comet's dusty path.
Your child walks round the hoop as the Earth. Every time they come to the rice, they 'collect' some: a meteor shower. Say: The Earth crosses the same stream at the same time every year.
Rain on the window
Read the book's rain picture:
Or look at the rain-drops on your window some dull and rainy day.
SayThe few meteors we see are like the few drops on one window. There are many more everywhere else.
What we know now
Comets leave trails of dust as their ice turns to gas near the Sun. When the Earth passes through such a trail, we get a meteor shower. The August Perseids come from Comet Swift-Tuttle; the November Leonids from Comet Tempel-Tuttle.
The great Leonid display the book expected in 1899 was a disappointment, because the planets' pulls had nudged the stream aside. But the Leonids put on spectacular storms in 1966 and again around 1999 to 2002.
Tell it back
Ask your child to explain, with the hoop and rice, why the Leonid meteors come back every November.
Check questions
Why are the November meteors called the Leonids?
How often does the Leonid stream give a grand display?
What is the connection between a comet and a meteor stream?
Answers to the book's problems
Because they seem to shoot out from a spot in the constellation Leo. About once every thirty-three years. They travel along the same orbit; the meteors seem to belong to the comet.
Worked out for this site from the scan. If a number in your copy differs, trust the book.