SC.5.E.5.3 Form A

1. There are lots of objects in our solar system, but only eight of them are planets. What do all planets have in common?

• They are all made of rock or ice.
• They all have rings or moons as satellites.
• They are all nearly round and orbit the sun.
• They all rotate on an axis and orbit the Earth.

2. All planets in the Solar System are categorized as inner or outer planets. Which answer describes how the inner planets are similar to each other?

• They are all the same size.
• They all have solid surfaces.
• They all have at least one moon.
• They all have a thick atmosphere.

3. Tom and his friends were talking about what it would be like if they could go live on Mars someday. Mandy said it would be much colder there than on Earth and it would hardly ever get above freezing even in summer. Jose said there would be time periods on Mars like there are on Earth.What else might they experience if they ever went to live on Mars?

• A year on Mars would last almost as long as two Earth years.
• Water would run in the canals on Mars on only the warmest days.
• They would see four big moons and several smaller ones at night on Mars.
• They could breathe the air since Mars and Earth have similar atmospheres.

4. When comets come close to the sun, they develop a tail that glows so we can see it from Earth. Asteroids do not develop tails like this.In what other way are asteroids different from comets?

• Asteroids orbit planets while comets orbit the sun.
• Asteroids are rocky while comets are balls of ice and dust.
• Asteroids orbit outside of the Solar System while comets do not.
• Asteroids are smooth and round while comets are lumpy shapes.

5. Which of the following describes one way that Mars and Earth are different?

• Mars has a moon but Earth does not
• Earth has an atmosphere but Mars does not.
• Earth is an inner planet and Mars is an outer planet.
• A year on Earth is about half as long as a year on Mars.