A group of protesters gather outside the White House, chanting and singing songs. On CNN one of them says, "Like whoa Mister President! Our mother Earth is in horrible danger from this nasty space meteor! It's over 109 nanometers in diameter and has a mass of over FIFTY THOUSAND GRAMS! This bogus thing is made of the same material as the Meteor Crater in Arizona, and it's totally gonna get within a thousandth of an AU to our sacred planet! If this destroys the Earth, that would have a majorly bad effect on the rain forest! Mister President, you gotta give us, like 150 billion dollars or so, and create like a new government agency to save us all! Anything else would be bad karma!
The President turns to you, his Science Advisor, and asks
(a) "How big is this object in everyday terms? " (Give an example of an everyday object that has this size. Give an example of an everyday object that has this mass.)
(b) "How close will it get?"
(c) "If this survived the atmosphere intact and hit the Earth, how big of a crater would it make"
(d) "Should we worry and/or do anything?" Explain.