P2 - Threats to Earth Flashcards
1
Q
Why did most plants become extinct 65 million years ago?
A
1) an asteroid hit earth
2) a cloud of dust and water vapor was thrown into the upper atmosphere and spread
3) sunlight could not get through the dust
2
Q
What is the origin of the moon?
A
1) another planet hit earth
2) dense rock became concentrated on earth
3) less dense rock began to orbit the earth
3
Q
What is a comet?
A
A comet is a chunk of ice filled with rock and dust.
4
Q
What do we do if a NEO approaches?
A
One option is to launch a rocket containing a large explosive to change the path of it.
