You realize that the potential exists for a collision between this comet and the Earth, so you start to worry about how much damage would be done by an impact. If the comet hits the Earth, how much kinetic energy will be released? (Think carefully about the relative velocity between the Earth and the comet) If a hydrogen bomb releases about 15 megatons of energy, how many Hbombs is this impact equivalent to?
Do you want to be around if Comet Mihos hits?
In this problem, we will
calculate the parameters of a Hohmann transfer
orbit which will take us from Earth to Mars. A Hohmann orbit is
an orbit which goes from one planet to another using the least amount
of energy. It is an elliptical orbit
whose perihelion is at the Earth's orbit, and whose aphelion just
reaches the orbit of the other planet (see figure to the right).
The trick, of course, is that the other planet has to be at the right spot to rendezvous with the spacecraft! So you need to calculate three things:
(For more fun with transfer orbits, you can also play with the Grand Tour applet.) 
