The asteroid belt

Much emptier than we imagine

You need a telescope

The numbers

Several probes have crossed it without any trouble: the asteroids are so far apart that they never meet.

Half of its whole mass is in only four bodies; the rest is crumbs.

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

When two big asteroids collide, a family of fragments with similar orbits is born.
Most of the starting mass was lost in the first hundred million years of the Solar System.
Ceres and Pallas were once thought to be the remains of a planet that had exploded.
The total mass of the belt is far too small for that idea to hold up.
The pieces never joined into a planet because of the gravity of Jupiter, which formed right next door.

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

Where is the asteroid belt?

Question 2 of 5

How crowded is it?

Question 3 of 5

What is the biggest body in the belt?

Question 4 of 5

Why didn't a planet form there?

Question 5 of 5

How much mass does the belt have in all?

In the movies I am a maze of boulders you have to zigzag through; in real life whoever crosses me does not even notice being inside. What am I?

I sit between two very different planets, a small red one and a huge one. The second is the reason I never became a world. What am I?

All my stuff, piled together, would not add up to a Moon, and yet I fill a ring millions of miles wide. What am I?

Activity 1

With a backyard telescope, on a dark night, Vesta can show up as a dot that moves from night to night among the fixed stars.

Activity 2

Look up the name of an asteroid discovered on your birthday: there are thousands of them, and almost all have a name and a date.

dwarf planet: A body big enough to be round, but that has not cleared its orbit.
asteroid family: A group of fragments born from the same collision, with similar orbits.