Best Meteor Shower This Year

LittleRedStar writes "This Wednesday night and Thursday morning is the peak of the Geminid meteor shower. This is the typically the best meteor show of the year with up to 100 meteors per hour. This year the moon is a nuisance, but with the peak predicted for early Thursday morning it is worth getting out and watching. Since the Perseid meteor shower was washed out from the moon and the Leonids were a bust, this should be the best for 2006."

Comments

Re:Almost extinct comet?

[MichaelSmith]

How do you work that out? Impulse = integral (F .dt) = change of momentum, momentum = mass * velocity. Seems the same impulse gives the same velocity change, if the mass remains constant.

Think about it this way: you are the Cassini probe transiting Jupiter on your way to Saturn. Approaching Jupiter its gravity sucks you in, increasing your speed. You do a burn at closest approach and increase your speed further. As a result you spend less time inside Jupiters gravitational field on your way out, so you lose less speed than you gained on your way in.

The effect works the other way as well. Your own gravitational field pulls Jupiter a bit towards you as you approach and the tug in the other direction is slightly smaller (because of your greater speed) after the flyby. The result is that Cassini and Jupiter exchange a small amount of momentum.

Re:Almost extinct comet?

[MichaelSmith]

Shifting Jupiter from its orbit?

I think the total velocity change from all our space probes was calculated to be about 1 foot per million years, or thereabouts.