Dumb physics question?

Question

If our planets mass was more or less would it change the speed at which we orbit? Would it be the same? Another persons question made me curious about this.

Also why doesn't the gravitational pull of the sun not suck us in to the sun eventually?

^^Please ignore the above double negative.

Answer 1

Orbits are driven by the gravitational forces between the bodies involved. That force is dependant on the masses of each body.

For two-body systems such as our planet and the sun, when one body is massively larger than the other (so that the center of gravity of the system, about which both bodies actually orbit, is within the radius of the larger body) it is assumed that the mass of the smaller body is only marginally important and can be disregarded.

That is to say that an increase in the planet's mass would have only a very, very slight effect on our orbit, making it the tiniest bit faster.

Even if the mass of the planet doubled, tripled, or increased by a factor or ten (!) it would still be a drop in the bucket compared to the mass of the sun, and our orbit would not change much.

Answer 2

For most purposes the speed can be considered to be just dependent on the distance from the sun.

While the planet's mass does have an effect, is is minor. It only starts to have a noticable impact when the mass gets really, really, really high, because then you are moving the barycenter. This is the "spot" that he earth and sun both orbit around, which currently would be somewhere inside the sun.

Answer 3

Yes the mass of the earth would affect our orbit. The fact is our gravity is pulling on the sun as hard as the sun is pulling on us. If you increase the mass of our earth we would orbit closer to the sun. although it would not change much.

Answer 4

Everything is wonderfully calculated