Our Solar System and Planets
Our Solar System Each of the 8 planets in our solar system are unique.
Our Solar System They are different in their: Size Motion Temperature Substances they are made up of Gravitational field strength
Our Solar System Orbit – Is the path that the planets follow (revolve) around the Sun.
Types of Planets There are two main categories of planets: Inner Planets Outer Planets
1. Inner Planets Also called Terrestrial Planets. Mercury, Venus, Earth and Mars. Composed of rock and metal Slow rotation Solid surfaces No rings Few satellites.
2. Outer Planets Jupiter, Saturn, Uranus, Neptune. Also called Gas Giants –atmosphere is made up mainly of gases – hydrogen and helium. Lack solid surfaces Fast rotation Many Rings and satellites
The 8 Planets and Pluto
Mercury #1 Smallest planet Closest to the sun Orbit is only 88 days Surface temp -173 to 427°C No Atmosphere Lots of craters
Venus #2 Almost the same size as earth Slowest rotation Hottest planet surface temp = 377 to 487°C Runaway green house affect
Earth #3 Tilted on its axis 23° Mild greenhouse effect Water in all three states Only planet with life One moon
Mars #4 About ½ the size of earth 25° tilt on its axis A year = 687 earth days Very cold -83 to -33°C Thin atmosphere No liquid water Two moons
Jupiter #5 Largest planet in our solar system 11x larger than earth Similar make up to a solar nebula, but much smaller, mostly H and He On day = 10 earth hours One year = 12 earth years 63 moons and counting Big red spot is a storm
Saturn #6 9x size of earth Mostly H and He Cold 56 moons and counting 29 year orbit Famous rings
Uranus #7 (yes funny, I get it!) First planet discovered with a telescope 4x size of earth Mostly ices with little H and He Blue from methane 11 rings 27 moons 84 year orbit Spins on axis 90°
Neptune #8 Also a methane atmosphere so appears blue 4 rings 13 moons 165 year orbit
Pluto 2/3 size of earth’s moon Downgraded from a planet to a dwarf planet Light from sun takes 5.5 hours to reach it Mostly rocky, methane and ice