Planet Power
Planets vs. Stars
Orbit Around
Space Objects
Model Detectives
100

Name the four terrestrial planets.

Mercury, Venus, Earth, and Mars

100

Which makes its own light: a planet or a star?

A star

100

What is the movement of a planet around the Sun called?

Revolution

100

What space object is made mostly of ice and dust?

A comet

100

What object should be at the center of a solar-system model?

The Sun

200

What do the inner planets have in common?

They are made mostly of hard, rocky material.

200

Which usually appears to twinkle in the night sky: a planet or a star?

A star

200

Which planet takes less time to orbit the Sun: one close to the Sun or one far away?

One closer to the Sun

200

What small rocky or metallic object orbits the Sun?

An asteroid

200

What object orbits Earth?

The Moon

300

Name the four outer planets.

Jupiter, Saturn, Uranus, and Neptune

300

What shape do both planets and stars generally have?

Nearly spherical

300

Which planet has the shortest year: Mercury, Earth, Mars, or Neptune?

Mercury

300

A space object follows a long, stretched-out path around the Sun. What is it most likely?

A comet

300

A model correctly shows the planets in order but not their true distances from the Sun. Is that a strength or a limitation?

A limitation

400

Which planet is closest to Neptune?

Uranus

400

Why can’t we usually see most stars during the daytime?

The Sun is so bright that its light overwhelms the light of the other stars.

400

Why does a planet closer to the Sun usually complete its revolution faster?

It travels along a smaller/shorter orbit.

400

Why is Pluto called a dwarf planet instead of a full planet?

It has not cleared its orbit/orbital neighborhood.

400

A picture shows four planets that all look round. Which conclusion is best supported: they all have moons, they all have thick atmospheres, or they are nearly spherical?

They are nearly spherical.

500

Jupiter and Saturn have moons and orbit the Sun. What statement would NOT be true about both of them?

They are the closest planets to the Sun.

500

A student says, “That blue object is a star because stars can be blue.” What observation would better help decide whether it is a planet or a star?

Whether it twinkles / whether it makes its own light.

500

On an orbit diagram, Planet A is on the innermost orbit and Planet B is much farther out. Which has the shorter revolution time, and why?

Planet A, because it has the smaller orbit and is closer to the Sun.

500

Which clue best separates a comet from an asteroid: “made of ice and dust” or “orbits the Sun”?

Made of ice and dust, because both can orbit the Sun.

500

A model shows the Moon and Sun both orbiting Earth. What is wrong with the model?

Earth and the other planets orbit the Sun; only the Moon orbits Earth.