READING ASSIGNMENT

What is the main threat to human existence according to most scientists?

• Volcanic eruptions

• Tsunamis

• Comets and asteroids

• Earthquakes

What is the difference between a comet and an asteroid?

• Comets have a tail of gas and dust, while asteroids do not

• Comets are larger than asteroids

• Comets burn up in the atmosphere, while asteroids reach the Earth's surface

• Comets only appear in our visible night sky once every ten years

What is the potential consequence of a comet or asteroid greater than 20km in diameter hitting Earth?

• Complete destruction of complex life

• Minor damage to the environment

• No significant impact

• Extinction of certain species

What is the role of Jupiter in protecting Earth from dangerous comets and asteroids?

• Jupiter destroys all comets and asteroids that come close to Earth

• Jupiter's gravitational field scatters away most of the dangerous comets and asteroids

• Jupiter absorbs the impact of any comets or asteroids that hit Earth

• Jupiter has no effect on the trajectory of comets and asteroids

What is a meteorite?

• A ball of rock and ice that sends out a tail of gas and dust

• A rock a few feet to several kms in diameter

• Part of an asteroid or comet

• It is a meteoroid when it hits Earth