Lesson 2: The Solar System Flashcards
This is the center of the solar system
Sun
The sun mostly consists of these 2 elements
hydrogen and helium
This is the process that releases the Sun’s energy.
nuclear fusion
The sun accounts for __% of our solar system’s mass
99%
What is the biggest planet in the milky way?
Jupiter
What are the 8 planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
This is known as the dwarf planet
Pluto
What are the planets that don’t have moons?
Mercury and Venus
How long does it take for the earth to travel around the sun?
365 days
How many moons does Jupiter have?
63
Moons are called natural _____
satellites
A regular, repeating path that one object in space takes around another one.
orbit
What do planets orbit?
Sun
This theory suggests that the universe began with a huge explosion
The Big Bang Theory
When was the universe created?
10-15 billion years ago
When was the Sun and the other planets created?
5 billion years ago
When did earliest life forms appear on earth
3.8 billion years ago
The earliest plants and animals appeared _______ years ago
700 million
When did dinosaurs become extinct?
65 million years ago
When did modern humans appear
100,000 years ago
In 150 AD, who suggested that the Sun is the center of the Solar System?
Ptolemy
In 1533 AD, who created a model of the solar system in which the Sun is at the center and the planets move in circles?
Copernicus