Maps And Globes Flashcards
Universe:
Matter and energy from the sun which gives us light and heat
Uni- one and verse- knowledge
The universe consists of:
Stars Planets Moons Asteroids Meteoroids Galaxies Comets
When the universe started
15 billion years ago - Big Bang
Matter cooled into hydrogen and helium
The suns gravity - stopped planets from flying off
Galaxies
Millions of stars held together by gravity
No exact number
Our galaxy
Milky Way part of the Local group
The sun takes 225 million years- galactic year to revolve
4 types of groups of galaxies
Spiral- most common
Irregular- no shape
Barred spiral- bar shaped
Elliptical- almost round
The Milky Way
Spiral shaped - blurred band of light, reflection which is so far away
The solar system
4.6 billion years old. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
How we know when something is a planet:
Needs to orbit the sun, enough gravity for a spherical shape, cleared the neighborhood of orbit
Asteroids or minor planets
Between Mars and Jupiter
1km to 1000km
Rock and iron in irregular shape
Meteoroids
Small pieces of debris/ rock .Orbit the sun. Gain of sand or large boulder. Burns up-Earths friction.
Meteor
When it entered Earths atmosphere. Bright spark of light- crater
Meteorites
Don’t burn up and strike the ground. 5000- marble and soccer ball size every year. Large- leave crater
Meteoroids, meteors and meteorites
Meteoroids- in space. Meteor- in our atmosphere. Meteorites - on Earths surface
Comets
Frozen gas, rock, ice and dust. 200m to 50 km. Nucleus heats up, evaporates - cloud of gas, dust- coma. Suns radiation- sweeps it away - tail
