Elementary Astronomy

Which is bigger- a planet or a star?

• planet

• star

• I don't understand

What is this?

d

galaxy

star

gravity

planet

Jupiter is the biggest ​ (a)   in our ​ (b)   .

• planet
• solar system
• sun
• star
• space

The universe is...

• round

• small

• very, very, very big

• a solar system

Draw a solar system

About how many stars are in one galaxy?

• 100

• 10,000

• 93,000,000

• 100,000,000,000

A ​ (a)   is how far ​ (b)   travels in a year.

• light-year
• light
• black hole
• galaxy
• sun

At the center of every galaxy is a...

• universe

• star

• black hole

• computer