I'm curious, if someone were to be floating out in space. Would they eventually be captured by the gravitational pull from another planet or sun. To be more specific the person isn't anywhere near said planet or sun they are just passing between them. My question, is there some sort of current in between planets or sun that can have the slightest effect on an object passing through?

  • $\begingroup$ Being out in space isn't different, in terms of gravity, from being on Earth. You feel force from all the planets just standing on Earth ( see this question for info on that ). $\endgroup$
    – StephenG
    Jul 19 '17 at 5:14
  • 1
    $\begingroup$ A good answer should probably have graphics, but loosely speaking everything in space orbits everything else. Not always an elliptical orbit but also parabolic or hyperbolic fly-by where the object is moving too be captured. I don't like to think of it as a current but if that works for you, that's fine. I like to think of it in terms of relative and tangential velocity and escape velocity. You plug in the numbers of relative velocity and you know which conic section to use. cseligman.com/text/history/ellipses.htm There's always some orbital effect. $\endgroup$
    – userLTK
    Jul 19 '17 at 6:14
  • 1
    $\begingroup$ You have a misconception about things "floating" in space. They are only floating in the same way that you would be floating inside a lift (elevator) if the cables were cut. $\endgroup$
    – ProfRob
    Jul 20 '17 at 19:26

There are no currents.

It all depends on the initial speed of the object, and the distance to the sun and planets.

If it's moving pretty slowly initially, it will eventually get captured in a loop orbit around some planet or maybe around the sun.

If it's moving pretty fast initially, it will described a trajectory through the system and eventually leave, never to return.

This is no different from what happens to asteroids, comets, the planets themselves, etc. This is all the play of gravity. This is called orbital mechanics. It's part of what is popularly known as "rocket science".

There is an app called Universe Sandbox. Install it on your computer and play with some solar system simulations. Setup a simulation with a central star, and just one body near it. Launch the body with various speeds. See what happens. The various scenarios unfolding from there are the answer to your question.


Any point in space feels the gravity of the whole observable universe around it.

If you are in the middle of nothing, then the gravitational field you measure can be incredibly low. But from small differences of mass and energy density throughout the (constantly moving) universe, it fluctuates, and drag you around in a direction or another, as long as you are mass or energy or spacetime.

If you are close to a massive object, on the other hand, then you are strongly bound to it by gravity, you will measure a strong field. Now if you have an equivalently massive object on the opposite of your position, gravity field is high, but the force you feel from is low in this place, because it annihilates (even with different mass bodies, this is what happens at Lagrangian point L1).


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.