The inner planets - Mercury, Venus, Earth, and Mars - are made of rock and metal and have solid surfaces. Mercury is the smallest planet and closest to the Sun, resulting in extreme surface temperatures. Venus is similar in size to Earth but its dense atmosphere creates a strong greenhouse effect, making it the hottest planet. Earth has liquid water and a atmosphere that supports life. Mars is around half the size of Earth, with a thin carbon dioxide atmosphere and seasonal polar ice caps.

1. Chapter 11 Lesson 2: The Inner Planets – p 382-387 – page 1
Vocabulary
 Terrestrial planet (383) – planets closest to the Sun, made of rock and metal, and have solid
outer layers
 Greenhouse effect (385) – occurs when a planet’s atmosphere traps solar energy and causes
the surface temperature to increase
Planets Made of Rock
o The inner planets –_____________________________________________________–
are also called terrestrial planets.
o _____________________ planets are the planets closet to the Sun, are made of rock
and metal, and have solid outer layers.
Mercury
• Facts
o The _____________ planet; closest to the Sun
o No______________________________
 The strength of a planet’s gravity depends on the planet’s_______________.
 Because Mercury’s mass is so______________, its gravity is not strong
enough to hold onto an atmosphere
o No atmosphere = no __________________
o Temperatures:
 _____________ on the side facing away from the Sun
 _____________ on the side facing the Sun
• Mercury’s Surface
o Many impact__________________, depressions formed by collisions with objects
from space
o High cliff and smooth plains from ancient volcanoes
o Without an atmosphere, almost no ____________________occurs on Mercury’s
surface
 As a result, features that formed billions of
years ago have changed very little.
• Mercury’s Structure
o Like all inner planets, Mercury has a core made of
___________and _____________.
o Surrounding the core is a layer called
the___________________.
o The crust is a thin, rocky layer above the mantle.
o Mercury’s ______________core might have been
formed by a collision with a large object during
Mercury’s formation.
Venus
• Facts
o 2nd
planet from the Sun
o About the same size as ___________________
o It rotates so slowly that its period of ____________________is longer than its
period of_____________________.

2. Chapter 11 Lesson 2: The Inner Planets – p 382-387 – page 2
 One is longer than one year
o Venus rotates east to________________, unlike most planets
• Venus’s Atmosphere
o The atmosphere of Venus is about 97% _________________
o It is so dense that the atmospheric pressure on Venus is about
___________________times greater than on Earth
o Venus has no water on its surface.
o It is covered by a thick layer of clouds made of __________________
• The Greenhouse Effect on Venus
o With an average temperature of about 460°C, Venus is the ____________________
planet in our solar system.
o The high temperature are caused by the ____________________________ effect
 The greenhouse effect occurs when a planet’s atmosphere traps
________________ energy and causes the surface temperature to increase.
o Without the greenhouse effect Venus would be about 450°C cooler!
• Venus’s Structure and Surface
o Venus’s internal structure is similar to
Earth’s.
o Radar images show that more than 80%
of Venus’s surface is covered by solidified
_____________.
Concept Check
• How are the inner planets similar?
• Why is Venus hotter than Mercury?
Earth
• Facts
o The third planet from the Sun
o Unlike Mercury and Venus, Earth has a________________.
• Earth’s Atmosphere
o A mixture of gases and a small amount of water vapor make up most of Earth’s
atmosphere
o They produce a ________________________ effect that increases Earth’s average
surface temperature
o This effect and Earth’s distance from the Sun warm Earth enough for large bodies
of water to exist.
o Earth’s protective atmosphere, the presence of liquid water, and the planet’s
moderate temperature range support a variety of life
• Earth’s Structure
o Earth has a solid inner core surrounded by a _____________________ outer core

3. Chapter 11 Lesson 2: The Inner Planets – p 382-387 – page 3
o The mantle surrounds the liquid outer core.
o Above the mantle is Earth’s___________________.
o It’s broken into large pieces, called_______________________, that constantly slide
past, away from, or into each other
Mars
• Facts
o 4th
planet from the Sun
o _______________________the size of Earth
o Two very small and irregularly shaped ______________________
o Water on Mars is mainly trapped in the polar ice caps and a small amount in found
as liquid vapor
 However, little evidence of liquid water or life has been found
• Mar’s Atmosphere
o 95% carbon dioxide
o Temperatures: -125°C – _____________
o Dust storms that last for months
• Mar’s Surface
o Reddish due to ___________ _____________ in the soil (rust)
o Enormous canyons
o Largest ________________________ in the solar system
o Polar ice caps made of frozen carbon dioxide and ice