Solar system vocab

geocentric system Ptolemy – 140 A.D. Greek Astronomer believed that Earth was the center of the universe

heliocentric system Nicolaus Copernicus – 1500s Polish astronomer- thought that the sun is at the center of the system- current model thanks to Galileo looking through telescope

solar system Large planetary system with many smaller planetary systems and objects (planets and their moons)

ellipse elongated circle, oval shape Path of orbit Not a perfect circle

nuclear fusion 2 hydrogen = helium= sun H H He

core #5 on picture nuclear fusion reactions = energyfusion reactions core is a very dark place! Made of Plasma

Photosphere #4 on picture Sphere that makes light Part we can actually see

chromosphere #2 on picture Middle layer Means color

corona #1on picture Outer layer looks like a halo or crown Only visible during eclipses

Sunspot #3 on picture Areas of gas on the sun that are cooler Look darker

prominence #6 on picture Huge loop of gas

solar wind Corona sends our a stream of electrically charged particles aurora borealis- northern lights

solar flare Huge explosions on the sun

terrestrial planets Mercury, Venus, Earth & Mars Four inner planets are small and have rocky surfaces

Gas giants Jupiter, Saturn, Uranus & Neptune Large outer planets with stronger gravity Keeps gases from escaping

rotation Spinning motion of a planet about it’s own axis ONE DAY 23 hr 57 min 4 sec (Earth) DIFFERENT FOR EACH PLANET

satellite Any object that revolves around another object in space Natural satellite = moon Artificial satellite= machine (cell phone signals)

revolution One year Earth days (365) February leap year every 4 th year Movement of an object going around another object

retrograde rotation Venus- travels east to west= clockwise Opposite direction of most planets It’s day is longer than it’s year

greenhouse effect Carbon dioxide traps heat in the atmosphere Venus’ surface becomes hotter and hotter Trapping heat

mnemonic device My Very Educated Mother Just Served Us Nine Pizzas Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto