Somebody in the office was defending astrology. Their argument went something like this: You concede that the Moon is known to effect natural phenomena on Earth. Jupiter is a far larger body, although granted it is further away, so it must have some effect as well.

Astrology Smackdown

Newton's law of universal gravitation: 
http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation

F = G(m1 * m2)/r^2

Mass of the Earth: 5.97219 × 10^24 kg

Mass of the Moon: 7.3477 × 10^22 kg
Distance to the Moon (average): 384,400 km

Mass of Jupiter: 1.8986 × 10^27 kg
Distance to Jupiter (closest): 628,743,036,000,000 km 

Since G and m(earth) are constant, the ratio of F(moon)/F(jupiter) =

m(moon)/r(moon)^2  /  m(jupiter)/r(jupiter)^2 =

103,292,899,632,434

So the force of the moon on the earth is 103 Trillion times that of Jupiter.

----------- python session ------------------------
$ python
Python 2.7.3 (default, Dec 18 2012, 13:50:09)
[GCC 4.5.3] on cygwin
Type "help", "copyright", "credits" or "license" for more information.
>>> m_moon = 7.3477 * (10^22)
>>> m_moon
205.73559999999998
>>> m_moon = 7.3477e22
>>> m_moon
7.3477e+22
>>> r_moon = 384.400
>>> r_moon
384.4
>>> r_moon = 384400
>>> r_moon
384400
>>> m_jup = 1.8986e27
>>> m_jup
1.8986e+27
>>> r_jup = 6.28e14
>>>
>>> f_moon = m_moon/pow(r_moon, 2)
>>> f_moon
497261296711.1739
>>> f_jup = m_jup/pow(r_jup, 2)
>>> f_jup
0.0048140898210880766
>>> f_moon / f_jup
103292899632434.22
>>>