As graduating seniors, we are getting old. No more high school, it's off to college! But, just how old are we? On the earth we are about 18 years old, give or take a few months. Because the other planets are different distances from the sun, they have different periods of revolution. Therefore, in relation to many planets we are very young (Neptune) or very old (Mercury).
A planet's period is given by:
= distance from planet's aphelion to sun
= distance from planet's perihelion to sun
Periods of planets (in Earth years):
Age of 18 year-old earthling on planets:
As period increases, one's relative age on that planet decreases.
So, as seniors, we may be walking the stage soon; but on Mars, we would only be half-way there!