The Earth and Space Flashcards
How do we find evidence for changes in the Earth?
Looking at rocks
Around how old are the oldest rocks on Earth?
4000 million years old
What is the Earth made up of? [4]
[1] Crust
[2] Mantle
[3] Outer core
[4] Inner core
What is the outer core made of?
Liquid nickel and iron
What is the inner core made of?
Solid nickel and iron
What are asteroids?
Much smaller than planets, but orbit the sun
What are moons?
They orbit planets
What are comets?
Comets are similar in size to asteroids, but are made of dust and ice. The ice melts when the comet approaches the Sun, and forms the comet’s tail.
How big is the Sun’s diameter compared with Earth’s?
Over 100 times as big
What is the Sun our source of?
Energy
What is the energy source of the Sun a result of?
Nuclear fusion
What happens in nuclear fusion?
Hydrogen nuclei are joined together to make helium nuclei, releasing a massive amount of energy
What do scientists believe our solar system is made from?
The remains of an earlier star
How is a star formed?
When gas falls together and becomes hot enough to start nuclear fusion
How old is the Universe currently believed to be?
14 million years
How far is the Sun from the earth?
150 million kilometers
What is a light year?
The distance light travels in a year
How fast does light travel per second?
300,000km
How many light years is the diameter of the Milky Way?
100,000
