# If there is a person on another planet, and his year is 80 Earth's years, how far would his planet have to be from the Sun?

Asked by Sneki95 (6997) May 9th, 2017

Imagine Bob. He lives on another planet. Let’s say he’s in our galaxy. Or not, doesn’t matter. His planet is going around a sun. Any sun.

One year in his time is 80 years on Earth. Take into account the distance between the Earth and the Sun.

How far away from the sun does his planet have to be, in order for it to travel around it long enough to achieve this?

How about the other way around? Our year is 80 years in his planet.

Observing members: 0 Composing members: 0

Here you GO * * * Uranus takes 84 years to orbit the sun it is 2,870,972,200 km from the sun or 1,783,939, miles.

@Tropical_Willie So, it would have to be a bit closer than Uranus, but somewhere in that distance. Thanks.

Sneki95 (6997)
Rarebear (25159)

@Rarebear AAAAAH math! [runs away]

Kidding, thanks for the link.

Sneki95 (6997)

Note that the distance between the star and the planet is not the only relevant variable. The mass of the star and the planet also affect the period of revolution.

Zissou (2962)

@Zissou Actually the mass of the satellite is irrelevant. See my math link above and scroll down to the orbital speed equation.

Rarebear (25159)

Search me, I’m still trying to wrap my mind around the Alien Autopsy.

NomoreY_A (5498)

@Rarebear. Mass is absolutely relevant.

filmfann (47601)

@filmfann The mass of the central body, yes.

The formula: velocity of orbit = sqrt(G*Mcentral)/R)

Rarebear (25159)

or