Our Solar System

Objectives Essential Question Objectives What would life be like on another planet? Objectives Describe conditions on other planets in our solar system Explain why the planets have different conditions (Inner vs. Outer)

Retrograde Motion Retrograde motion A planet’s apparent backward motion in the sky Similar to passing a slower car

Measuring Distance in Space Astronomical Unit (AU) A planets average distance to the Sun Sun to Earth = 1 AU = 1.496x108 km

Kepler’s First Law Perihelion – When a planet is closest to the sun in its orbit Aphelion – When a planet is farthest away from the sun in its orbit Eccentricity – The shape of a planets elliptical orbit

Terrestrial Planets Inner Planets

Mercury No Moons 1/3 size of Earth Mercury has essentially NO atmosphere

Surface covered with craters and plains Nickel Iron core Mercury Temp ranges from 700 K to 100 K Due to slow rotation and proximity to the sun Surface covered with craters and plains Nickel Iron core Molten Zone in the interior

Venus No Moons Average temp: 737 K (Runaway Greenhouse Effect) Almost 90 times greater pressure Retrograde Rotation

Venus Atmosphere has Carbon Dioxide and Nitrogen Surface smoothed by volcanic lava flows, few impact craters Interior similar to Earths

Earth One Moon Water on Surface Atmosphere 78% N and 21% O

Mars Two Moons Thin Atmosphere with constant wind

Mars Southern Mars is heavily cratered and high lands Northern Mars dominated by plains with few craters 4 Shield Volcanoes – Olympus Mons Large because there are no moving tectonic plates Polar Ice caps – dry ice over water ice Interior – Solid Nickel Iron Core

Gas Giant Planets Outer Planets

Jupiter Eleven times larger than Earth Atmosphere contains H and He Great Red Spot – Atmospheric Storm that has been rotating for more than 300 years.

Jupiter Four Galilean (Satellites)Moons: Io, Europa, Ganymede, Callisto Moons are composed of Ice and Rock mixtures Jupiter has a Ring

Saturn Atmosphere composed of Hydrogen, Helium and Ammonia Ice near top of clouds

Saturn Rings composed of pieces of rock and ice (Range in size from microscopic to the size of a house) Seven Major rings made up of narrower rings Gravity of Saturn keeps the rings from coming together to form a moon 18 Satellites, largest is Titan

Uranus Atmosphere contains Hydrogen, Helium and Methane Gas Methane gives planet its bluish color

Rotational Axis is tipped 18 Moon and 10 rings Uranus Rotational Axis is tipped Possibly caused by a collision 18 Moon and 10 rings Rings are dark in color and hard to see Temperature avg. -215 C

Neptune Atmosphere contains Hydrogen, Helium and Methane Has clouds Great Dark Spot – Storm disappeared in 1994

Eight moons – Largest Triton Neptune Eight moons – Largest Triton Triton has a retrograde orbit Neptune has 6 rings composed of microscopic dust particles

Pluto Has a solid Surface Not a Terrestrial Planet or a Gas Giant Planet Half Ice and Half Rock Pluto has a Moon – Charon Past Kuiper Belt Status recently changed – No longer a planet : (