Homework FIVE

Due Monday, March 17, 2003, at beginning of class.

Late penalty: 5 points if turned in by noon, Wednesday, 3/19. Not accepted
after classtime on 3/19.

Answer Key

Calculate the loss rate for a comet in gms/sec, assuming a particle loss
rate at 1 AU of 5 x 10^{28} molecules per second. Assume all the
molecules are water. If the comet density is 1 gm/cm^{3}, what
is the volume of ice lost if the comet loses mass at this rate for 3 months?
If the comet begins with a radius of 3 km, what is the radius of the comet
after one passage (and mass lost event of 3 months)?

How many typical comets would it take to provide Earth's entire water supply?
(Assume each comet is 80% water; assume the total water supply on the earth
can be taken as the mass of the oceans, 10^{18} kg).

If 50 billion comets have passed through the inner solar system over the
age of the solar system, what is the total mass removed from the Oort Cloud
and Kuiper Belt through this process? Based on this calculation,
make an estimate as to how much mass might have been lost from the Oort
Cloud and Kuiper Belt over 4.5 billion years. You will need to make
assumptions as to how much mass is kicked out of these reservoirs but never
makes it into the inner solar system.

An object is discovered with a semimajor axis of 1.7 AU and eccentricity
0.41. What kind of object is this?

About 100 metric tons of meteoritic material rain down onto Earth's surface
every
day! How much mass does this add up to, as a fraction of
the Earth's mass, after 4. 5 billion years, assuming this rate has been
constant for 4.5 billion years? Do you think this is enough mass to substantially
affect or alter the Earth?

What is the 'big picture' significance of the Allende meteorite?

What is the 'big picture' significance of the Murchison meteorite?