# How would you calculate Pluto's aphelion distance?

## If eccentricity = .248 and perihelion = 29.73au

Dec 30, 2015

Aphelion = 7.38 x ${10}^{9}$ km

#### Explanation:

To calculate Perihelion and Aphelion distances you will need the eccentricity of Pluto's orbit and the semi-major axis which is usually the average distance between Pluto and the Sun.

Perihelion = a (1 - e)
Aphelion = a (1 + e)

Where,

e is the eccentricity of the orbit
a is the semi-major axis

e in case of Pluto is 0.25
a in case of Pluto is 5.91 x ${10}^{9}$ km

Perihelion = 5.91 x ${10}^{9}$ (1 - 0.25)

Perihelion = 4.43 x ${10}^{9}$ km

Aphelion = 5.91 x ${10}^{9}$ (1 + 0.25)

Aphelion = 7.38 x ${10}^{9}$ km