The Inner The Inner PlanetsPlanets

The Inner PlanetsThe Inner Planets

Mercury, Venus, Earth, and MarsMercury, Venus, Earth, and Mars Inner Planets are small, dense and Inner Planets are small, dense and

have rocky surfaces.have rocky surfaces. Called “terrestrial” planets.Called “terrestrial” planets.

EarthEarth Earth is made up Earth is made up

of three layers: of three layers: Crust – the solid Crust – the solid

rocky surfacerocky surface Mantle – hot Mantle – hot

molten rockmolten rock Core – dense inner Core – dense inner

layer made of iron layer made of iron and nickeland nickel

Only planet with Only planet with liquid waterliquid water

Earth’s gravity Earth’s gravity keeps gases in to keeps gases in to create our create our atmosphere atmosphere (mostly oxygen (mostly oxygen and nitrogen)and nitrogen)

MercuryMercury Smallest inner planet Smallest inner planet

(not much larger than (not much larger than Earth’s moon)Earth’s moon)

Closest to the sunClosest to the sun Mercury’s surface has Mercury’s surface has

flat plains and cratersflat plains and craters Mercury has no Mercury has no

atmosphere because it atmosphere because it has very little gravity. has very little gravity. Gases escape out into Gases escape out into space as they heat up.space as they heat up.

Mercury has extreme Mercury has extreme temperature difference temperature difference (-170 °C to 430 °C) .(-170 °C to 430 °C) .

VenusVenus Known as the ‘evening Known as the ‘evening

star’ because we can star’ because we can see it just after sunset.see it just after sunset.

Its density and Its density and structure are similar to structure are similar to Earth’s (Earth’s twin)Earth’s (Earth’s twin)

Venus’s day is longer Venus’s day is longer than its year (day=8 than its year (day=8 months, Year = 7.5 months, Year = 7.5 months)months)

Rotates from east to Rotates from east to west (opposite from west (opposite from other planets). A other planets). A possible collision possible collision caused the change in caused the change in direction.direction.

VenusVenus

Venus has a very thick atmosphereVenus has a very thick atmosphere Weight of it would crush youWeight of it would crush you Mostly carbon dioxideMostly carbon dioxide Clouds are made of droplets of sulfuric acidClouds are made of droplets of sulfuric acid Greenhouse effect traps the heat from the Greenhouse effect traps the heat from the

sun in making Venus the hottest planetsun in making Venus the hottest planet The surface of Venus is mostly rock with The surface of Venus is mostly rock with

volcanoes and plains formed by lava volcanoes and plains formed by lava flowsflows

MarsMars The “red” planet from The “red” planet from

the break down of iron-the break down of iron-rich rocks.rich rocks.

Atmosphere is more Atmosphere is more than 95 % carbon than 95 % carbon dioxide (similar to dioxide (similar to Venus). It is so thin that Venus). It is so thin that liquid cannot exist liquid cannot exist (would turn to gas in the (would turn to gas in the atmosphere atmosphere immediately)immediately)

Scientists believe that Scientists believe that large amounts of water large amounts of water once flowed on Mars. once flowed on Mars. This left huge canyons This left huge canyons and the appearance of and the appearance of ancient coastlines.ancient coastlines. Remaining water is frozen Remaining water is frozen

in Mar’s polar icecaps.in Mar’s polar icecaps.

MarsMars

Mars has a tilted axis so it has a Mars has a tilted axis so it has a changing seasonschanging seasons

Mars has 2 small moons (Phobos and Mars has 2 small moons (Phobos and Deimos)Deimos)

Mars has giant volcanoes that appear to Mars has giant volcanoes that appear to have erupted in the past.have erupted in the past. They are not active nowThey are not active now Olympus Mons is the largest volcano in the Olympus Mons is the largest volcano in the

solar system (3 times the size of Mount solar system (3 times the size of Mount Everest)Everest)