Week 5 Notes Inner
Planets
Ch. 3, Sect. 3
Page 84 – 91
I. INNER PLANETS
a. The __FOUR__ inner planets are __SMALL__ and __DENSE__
and have __ROCKY__ surfaces.
b. The inner planets are known as the __TERRESTRIAL__ planets
c. The __4__ inner planets are: __MERCURY__, __VENUS__,
__EARTH__, and __MARS__
1. EARTH
a. Earth has __3__ main layers: __CRUST__, __MANTLE__, and
__CORE__.
A. Water
a. Earth is the __ONLY__ planet that has liquid __WATER__ on its
surface.
b. Earth is about __70%__ covered in __WATER__
B. Earth’s Atmosphere
a. Earth has enough __GRAVITY__ to hold o to most __GASES__
b. __OXYGEN__ is found in Earth’s atmosphere, it makes up about
__20%__ of the atmsphere
c. Other gases are __NITROGEN__, __ARGON__, and
__CARBON DIOXIDE__.
d. __WATER__ in a gaseous form is called __WATER VAPOR__
2. MERCURY
 a. Mercury is the __SMALLEST__ terrestrial planet and the
planet __CLOSEST__ to the __SUN__
 b. Mercury is not much larger than __EARTH’S__ moon.
A. Exploring Mercury
a. Missions to Mercury: __MARINER 10__ and __MESSENGER__
b. The surface has many __CRATERS__ which are named after __ARTISTS__,
__WRITERS__, and __MUSICIANS__
B. Mercury’s Atmosphere
a. Mercury has virtually __NO__ atmosphere
b. Due to Mercury’s low __MASS__ it has __GRAVITY__ is __WEAK__
c. Mercury has the __GREATEST__ temperature __RANGE__: High temps of
__430C__ and Low Temps of __-170C__
3. VENUS
a. You often see __VENUS__ just after __SUNSET__ or before __SUNRISE__
b. Venus is similar in __SIZE__ and __MASS__ to Earth and sometimes called
__EARTH’S TWIN__
A. Venus’s Rotation
a. Venus takes about __7.5__ Earth moths to __REVOLVE__ around the Sun.
b.
Venus takes about __8__ Earth Months to __ROTATE__ once on its axis.
c. So Venus’s __DAY__ is __LONGER__ than a __YEAR__
d. Venus also __REVOLVES__ from __EAST__ to __WEST__, which is different than most
planets.
B. Venus’s Atmosphere
a. Venus’s atmosphere is __THICK__ and is made mostly of __SULFRIC ACID__
b. Venus’s atmosphere is __90__ times greater than Earth’s and it would __CRUSH__ you quickly
c. The atmosphere __TRAPS__ most of the __HEAT__ making it the __HOTTEST__ planet in
the Solar System.
d. The average temperature is __460C__ so hot that it could melt __LEAD__
e. Trapping heat by the __ATMOSPHERE__ is called __GREENHOUSE EFFECT__
C. Exploring Venus
a. Mission to Venus: __VENERA 7__ and __MAGELLAN PROBE__
4. MARS
a. Mars is called the __RED__ planet due to the breakdown of __IRON__ rich rocs
A. Mars’s Atmosphere
a. The atmosphere is made up of __95%__ carbon dioxide
b. Temperature ranges on mars is __-140C__ to __20C__
B. Water On Mars
a. Scientists think that a __LARGE__ amount of liquid water flowed on Mars’s surface
in the __PAST__
b. Liquid water could __NOT__ last long on the surface. It would turn into a
__GAS__
C. Seasons on Mars
a. Mars has __SEASONS__ just like __EARTH__
D. EXPLORING MARS
a. Missions to Mars: __SPIRIT__, __OPPORTUNITY__ and __CURIOSITY__
E. Volcanoes on Mars
a. __OLYMPUS MONS__ is the largest volcano in the __SOLAR SYSTEM__
b. As large as the state of __MISSOURI__ and is __3__times taller than __MOUNT EVEREST__
F. Mar’s Moons
a. Mars has __2__ very small moons: __PHOBOS__ and __DEIMOS