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Message Subject They Changed the Date for 2005 YU55???!!!!
Poster Handle Halcyon Dayz, FCD
Post Content
If the moon were hit, I cannot do the math, but I know its orbit would be greatly affected, and its pull on earth would be modified.
Quoting: humuhumubannedbutgotthrough 3209328

(Emphasis mine)

Who are you trying to fool here?

Yourself?

Let's actually do the maths.
A back-of-the-envelope first Order of Magnitude calculation.

For simplicity we'll presume the asteroid is a cube 1 kilometre to a side, mostly made of lead, to get an average density 10 grammes per cubic centimetre, moving at a preposterous 100 km/s.

The mass of such an object would be 100,000(cm)^3 * 0.01 (kg/cm^3) = 10,000,000,000,000 kg or 10 billion tonnes.

The mass of the Moon is something like 7.35 × 10^22 kg.

Which is 7,350,000,000 times as much.

So in a perfectly inelastic collision the object can transfer 1/7,350,000,000 of its velocity on the Moon.

Which gets me 0.0136 millimetre per second.

There's a reason engineers and scientists call doing an OOM calculation a sanity check.

BTW, have you seen the size of some of the craters on the Moon?