Comet Neowise is a long period comet that was visible last July 2020. It has an orbital period of 4400 years. What is its mean distance from the Sun?

Answer 1

We have to speed of light C = 3·10⁸ m/s times half of this time (half there and half back) 2200 years,

so mean distance d = 2200 ly = 2200·9.4607 × 10¹² km = 2.0814 × 10¹⁶ km