# An asteroid has a perihelion distance of 2.4 AU and an aphelion distance of 4.4 AU? How do you calculate its orbital semimajor axis, eccentricity and period?

##### 1 Answer

Feb 9, 2016

a(1 - e) = 2.4 and a(1 + e) = 4.4. Solving, a = 3.4 AU and e =10/17 = 05882, nearly. The period is a X sqrt (a) = 6.27 years, nearly, using Kepler;s third law for approximation of the period..

#### Explanation:

When a is in AU unit and period is in years, period = a X sqrt (a). Here, a for the Earth is defined as 1 AU.