formation of the Earth Flashcards
1
Q
when was the universe formed
A
13.7 billion years ago
2
Q
when was the galaxy formed
A
4.6 billion years ago
3
Q
when was the sun formed
A
4.6 billion years ago
4
Q
when was water brought to Earth
A
3.9 billion years ago
5
Q
how was water brought to Earth
A
Earth was pelted by asteroids that contained water
6
Q
how many years ago was the Earth a molten ball of lava
A
4 billion years ago
7
Q
what are the names of the first living structures that caused life to form
A
stromatolites
8
Q
what is the waste product of stromatolites
A
oxygen
9
Q
what was the first form of life on Earth
A
single cell bacteria
10
Q
how long ago was the large continent
A
250 million years ago
11
Q
what was name of the large continent
A
