Inner Planet (Terrestrial Planets)

planets inside the asteroid belt

similar to Earth (consist of mostly rock & have a metallic core)

Mercury – Messenger god, closest to sun

Fastest Revolution - 88 days to orbit

Rotation – 59 days

1/3 the size of Earth

Surface is heavily cratered resembles the moon

Trace of an atmosphere (very thin)

Temperature range high of 427ºC to - 173ºC

Not the hottest planet

~ 1/3 gravity of Earth

Last space probe Messenger Oct. 2008

No Moons

Venus – 2nd planet from sun

goddess of love/beauty

-sometimes called the twin of Earth

Revolution takes 225 days

Longest rotation = 243 days to spin

Its day is longer than its year!

And it spins backward – Retrograde

Atmospheric pressure is 90 times greater than Earth

Very dense – mostly CO2 (96%) and clouds that contain sulfuric acid, makes Venus slight yellow color.

thick atmosphere causes a runaway greenhouse effect planet traps heat making it the Hottest planet : 464ºC

3rd brightest object in the sky (morning or evening star)

Most of the surface was mapped using radar from the space probe Magellan

In 1970’s the Soviet Union space probe took the 1st pictures of Venus surface, Space probes only lasted a few minutes until they quit working in Venus harsh environment.

No Moons

Venus surface

Earth – 3rd rock from the sun

only planet known to support life

big blue marble: 70% covered in water,

atmosphere 78% nitrogen, 21% oxygen, .5% CO2, .05% other gases

Revolution = 365.25 days,

Rotation = 24 hours

1 natural satellite (moon)

Mars – 4th planet from sun (red planet)

god of war, red due to iron oxide in the rocks and soil

twice as far away from the sun compared to Earth

Yea Notes About me!! Work you students!

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Revolution = 687 days,

Rotation = 24hrs. 37 minutes

Atmosphere – very thin CO2

Temperature range from 20º C to -130ºC

-during season changes creates global

dust storms

- polar ice caps can be seen (seasonal

effects)

Surface features:

Mars has been geologically active in past

Largest mountain/volcano :

Olympus Mons

Very large canyon – Valles Marineris which shows strong evidence liquid water may have flowed on Mars in the past

Two moons: Phobos & Deimos

(fear) (terror)

23 minutes for radio signals to reach Mars

At present day would take a year or more to travel to Mars and back.

Unmanned Space Probes to Mars:

Mariner 9 – 1971 orbited Mars took 1st close pictures

Viking 1&2 Landed on Mars 1971-72 examined surface and soil, took pictures of rocky surface

Mars Pathfinder & Sojourner

, which had 1st robot cars

Spirit & Opportunity (robots) – landed in 2004 exploring Mars surface

Phoenix 2008 – confirmed water ice in polar ice caps and frozen water under Mars surface soil in areas.