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