Chapter 2- Lesson 2Inner Planets

Cambridge- Make sure NB is updated. NB 81 has 2.2 and 2.3 Vocabulary, Bellringers, NB 82, 84, 86- Notes on 2.2 and 2.3, NB 83- Inner Planets Data Table, and NB 85- 2.2 Outline. Make sure all note pages have 3

questions created from notes.

Comprehensive- Here is a copy for your

Lesson 2-1• Earth and the other inner planets—Mercury, Venus,

and Mars—are also called the terrestrial planets.

• Like Earth, the other terrestrial planets are made of rock and metallic materials and have a solid outer layer.

Planets Made of Rock

Lesson 2-1The inner planets are roughly similar in size, with Earth being about two and half times larger than Mercury.

Mercury: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Venus: NASA

Earth: NASA Goddard Space Flight Center

Mars: NASA/JPL/Malin Space Science Systems

Lesson 2-2Mercury is the smallest planet and the planet closest to the Sun.

Lesson 2-2• Mercury’s gravity is not strong enough to hold an

atmosphere.

• Mercury’s temperatures are as high as 450°C on the side toward the Sun and as low as –170° on the side away from the Sun.

• Like all inner planets, Mercury has a core made of iron and nickel.

Mercury

Lesson 2-3Venus is the second planet from the Sun and is about the same size as Earth.

Lesson 2-3• The atmosphere of Venus is about

97 percent carbon dioxide.

• The pressure of Venus’s dense atmosphere is 90 times greater than that of Earth’s atmosphere.

• A thick layer of acid clouds covers Venus.

Venus

Lesson 2-3• The greenhouse effect occurs when a planet’s

atmosphere traps solar energy and causes the surface temperature to increase.

• Because of its greenhouse effect, Venus is the hottest planet in the solar system, with an average temperature of about 460°C.

Venus (cont.)

Lesson 2-4Earth is the third planet from the Sun.

Lesson 2-4• A mixture of gases, including water vapor, make up

Earth’s atmosphere and produce a greenhouse effect that raises its surface temperature.

• A protective atmosphere, moderate surface temperatures, and the presence of liquid water support a variety of life on Earth.

Earth

Lesson 2-5Mars is the fourth planet from the Sun and is about half the size of Earth.

Lesson 2-5• Images of Mars show features that might have been

made by water, though no evidence of liquid water or life has been found.

• The atmosphere of Mars is thin and made of about 95 percent carbon dioxide.

• Temperatures on Mars range from about –125°C at the poles to about 20°C at the equator during the summer.

Mars