Download The Inner Planets

The Inner Planets
Inner planets
• The 4 inner planets in order from the
sun—Mercury, Venus, Earth and Mars
• They are more similar to each other
than they are to the four outer planets.
• The four inner planets are small and
have rocky surfaces.
• These planets are often called the
“terrestrial” planets.
– Terrestrial means “relating to Earth”
Inner planets (put this table in your notes!)
Mercury
• Mercury
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Closest planet to the sun.
Not much larger than Earth's moon.
Has no moons of its own.
Very close to the sun so it’s hard to
get a good view of it.
• Many craters on its surface.
Mercury
• Has an extremely thin atmosphere.
• Planet of extremes.
• The temperatures can reach up to 430°C
(806°F) during the day and at night it can
drop to −170°C. (-274°F).
• Greater range of temperatures than any
other planet.
Venus
• Venus
• Similar in size to Earth.
• Density and internal structure of
Venus are similar to Earth's.
• However, in many other ways,
Venus is very different from Earth.
Venus
• Takes about 7.5 Earth months to revolve
around the sun.
• Takes about 8 months for Venus to rotate
on its axis.
• Venus rotates so slowly that its “day” is
longer than its “year.”
• Rotates from east to west, the opposite
direction from most other planets and
moons.
• This type of rotation is called retrograde
rotation.
Venus's Atmosphere
• Atmosphere is so thick that every day
is a cloudy one.
• Pressure of Venus's atmosphere is 90
times greater than the pressure of
Earth's atmosphere.
• Could not breathe on Venus because its
atmosphere is mostly carbon dioxide.
• Clouds are partly made of sulfuric acid.
The Surface of Venus
• Covered with rock,
similar to many
rocky areas on
Earth.
• Has volcanoes with
lava flows, many
craters, and strange
domes not found on
other planets.
Mars
Mars
• Atmosphere of Mars is mostly
carbon dioxide.
• Has only 1 percent the pressure of
Earth's atmosphere.
• Astronomers have found that some
water remains on Mars in the form
of ice at its north pole.
• Mars' south pole has an ice cap
made mostly of frozen carbon
dioxide.
Exploring Mars
• Axis is tilted so Mars has
seasons just as Earth
does.
• Barren and covered with
craters like the moon.
• Regions of Mars have giant
volcanoes.
• No oceans or puddles of
water exist.
• Photographs taken from
space do show evidence
that water flowed on Mars
millions of years ago.
Mars's Moons
• Mars has two very small moons.
• Phobos and Deimos.