# Is it possible to stand still in space?

I am wondering to know if it's possible to stand still (no movement at all with respect to the Sun) in space.

Can it be possible? I am thinking that when we move upwards from Earth's surface an upward thrust is needed. When we reach space, if we apply an equivalent opposite force, then can velocity go to zero and hence stand still in space?

• With continuous thrust, yes, you can remain in one position relative to a body such as the sun, but then, for 0 continuous thrust you can be in orbit about it at the same/similar distance. Is there any advantage to remaining suspended in one place (that's worth the thrust)? – Andrew Thompson Sep 2 '14 at 4:23
• @AndrewThompson you said continous thrust so do you mean oppsotite thrust? – SpringLearner Sep 2 '14 at 4:53
• If you sent an object on a parabolic orbit out of the solar system, your velocity wrt sun would get closer and closer to zero. At 1 light year out you'd be moving .17 km/s. 2 light years out you'd be moving .12 km/s. Further and you'd likely fall into the influence of another star and start moving faster wrt our sun. – HopDavid Sep 2 '14 at 5:06
• The sun's gravity is always bending your path. Unless you're moving straight from the sun along a radial vector. In which case your path would be a degenerate conic section. – HopDavid Sep 2 '14 at 13:52
• Since Earth moves at about 30km/s around the Sun, before you "stop" you'd need to brake first - accelerate by that 30km/s in direction opposite from Earth's velocity, to "stop". Then you could turn towards the Sun and thrust (very lightly actually, a mere 0.0059 m/s²). The latter is not a big problem; ion drives can provide that for months if not years. The former... I'm not sure if there is a single craft which has ever achieved that delta-V. – SF. Jan 23 '17 at 14:36

## 3 Answers

Yes, it is possible to be essentially standing still in relationship to the Sun. There are many comments and an answer telling you why you can't and, as far as they go, they are correct.

If you move far enough away from our sun, it become just another star. If you move to about half way between Earth and Andromeda, each galaxy will be so far away from you that no individual sun will have any reasonable impact on your position in space.

There are, of course, many things to consider, the spinning of the Sun, the Sun's orbit around the Milky Way, the movement of all the galaxies in the Universe.

If you travel about 1.25 million light years towards Andromeda, and kill your relative speed, you could stand essentially still in regards to our sun.

In the way you defined it, no motion relative to the sun, it is not possible to stand still, because the sun itself is not a solid object. Instead different latitudes rotate with different velocities.

http://en.wikipedia.org/wiki/Solar_rotation

You could stand still with regard to the sun's equator by being in a tight orbit around the sun with an orbital period of 24.47 days.

If I understand you correctly, however, you don't want to be in an orbit around the sun. If this is the case, you need to keep firing your engine, so you are not pulled into the sun. As HopDavid correctly pointed out to you, the most plausible concept for this is a Statelite. However, the sun will still be spinning below you, so you are still not fixed in place with regard to most of the sun.

From your question and subsequent replies, I think maybe you may enjoy reading a basic textbook on orbital mechanics. I don't think stackexchange can give you the structured introduction that you need in order to move on in this complicated subject.

• +1 for your last statement on the unstructured nature of Stack Exchange – Stu Sep 3 '14 at 4:07

You can't make the velocity zero and expect to stay there. you will need to constantly fire the engine to hold youself in position (this is possible, until you run out of fuel).

Yes, it is possible to fire the engine and lift off earth into space, and then fire in the opposite direction to earths movement until you are still, relative to the sun. But if you now turn the engine off, the suns gravity will pull you down and directly into the sun.

its the earths forward motion that prevents it falling into the sun