OCR 21st Century Science - Physics - Module One

Question	Answer
P1 REVISION THE EARTH in the UNIVERSE	.
How many planets are in the solar system	There are eight planets in the solar system
Other than planets, name three things that orbit the sun.	Dwarf planets, comets and dust
Approximately how old is the solar sytem?	The Solar system is about 5 thousand million years old.
What is the source of the Sun's energy?	The fusion of hydrogen nuclei.
What are comets made of?	They are balls of rock, dust and ice.
Roughly, how many stars make up the Milky Way?	100 000 000 000 stars!!!!
What is a light year?	A light year is the distance light travels through a vacuum in one year.
Roughly, how many times larger is the diameter of the Milky Way than the diameter of the Sun?	600 billion times the diameter of the Sun.

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	Created by joliverhouse over 9 years ago