1 AU = 150 million km = 1.5 x 10⁸ km = 1.5 x 10¹¹ m

G = 6.67 x 10-¹¹ N m² kg^-2

Speed of light = 3 x 10⁸ m/s

Seconds in a year = 60 x 60 x 24 x 365 = 3.14 x 10⁷ s

Mass of Sun = 2 x 10³⁰ kg

Mass of Jupiter = 2 x 10²⁷ kg

Mass of Earth = 6 x 10²⁴ kg

Radius of Sun = 7 x 10⁸ m

Radius of Jupiter = 7 x 10⁷ m

Radius of Earth = 6400 km = 6.4 x 10⁶ m

1 Light Year = Seconds in a year x Speed of light = 3.14 x 10⁷ s x 3 x 10⁸ m/s = 9 x 10¹⁵ m = 60,000 AU

V(1AU) = [GM_sun/1AU]^1/2 = 30 km/s

Masses of Jupiter, Saturn, Uranus, Neptune are 320, 90, 14, 17 Earth masses