Comets

Big dirty snowballs

You need binoculars

The numbers

The coma can grow wider than the Sun, even though it comes from a nucleus the size of a hill.

These are not in the book: there was no room on paper.

In comets, astronomers have found alcohol, formaldehyde and even some of the building blocks of proteins.
A comet loses a little of itself every time it passes close to the Sun: sooner or later it runs out.
The Giotto probe came within about 370 miles of Halley's nucleus and took the first pictures of it.
Comets have two different tails: a yellowish one made of dust and a bluish white one made of gas.
For centuries the arrival of a comet was thought to announce a coming disaster.

The first question is the one printed under the QR code, with the answer the book did not give. The other four only exist here.

Question 1 of 5★ is the one from your book

What is the nucleus of a comet made of?

Question 2 of 5

Why does a comet light up as it gets closer to the Sun?

Question 3 of 5

Which way does a comet's tail point?

Question 4 of 5

How much light does the nucleus of Halley's Comet reflect?

Question 5 of 5

Where do comets come from?

I have a coma without having hair and a tail without being an animal. My tail never follows me: it always runs away from the light. What am I?

I am made of ice and dirt, yet for centuries people were afraid of me. I always come back, but you have to be patient. What am I?

Activity 1

With a flashlight and a small ball of aluminum foil, try to guess which way the tail would point if the flashlight were the Sun.

Activity 2

Look online for when the next comet you can see will pass by, and mark the day on the family calendar with a drawn star.

coma: The glowing cloud of gas and dust that surrounds the nucleus.
sublimation: When ice turns straight into gas without becoming liquid first.