Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: scientizscht on 18/08/2019 16:11:42
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Hello
Is it possible to have a satellite that is on a fixed point in respect to earth's movement?
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Is it possible to have a satellite that is on a fixed point in respect to earth's movement?
Any geosync satellite is thus positioned, allowing one to permanently point a dish (like a home dish TV setup) straight at it and not have to track it across the sky.
At a radius of 42,164 km, the angular velocity around Earth is the same as that of Earth: 1 per day.
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Just a bit of correction to Halc's post. You need a geostationary orbit to maintain position over a spot on the Earth. While every geostationary orbit is geosynchronous, not all geosynchronous orbits are geostationary. A geosynchronous orbit is one where the orbital period equals the Earth's rotational period. So for example, a 24 hr long polar orbit is geosynchronous, returning to the same spot with respect to the ground every 24 hrs it doesn't remain over that spot for its entire orbit.
Geostationary orbits are limited to those that orbit over the Equator.( the only places on the Earth where you can have a satellite that always remains directly overhead are on the Equator. ) The region where you can put such satellites is known as the "Clarke Belt", named after the SF author A.C. Clarke, who is credited with being the first to suggest that satellites placed there would could be used as an aid to communication( he did this back in the 1940s before we had the ability to do it).
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I am not sure if I have been understood what I am asking.
I am looking for a satellite that is in a fixed point in the universe that it is in a FIXED distance and coordinates from the center of the earth.
Is that possible?
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What do you think the word "Satellite" means?
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I am looking for a satellite that is in a fixed point in the universe that it is in a FIXED distance and coordinates from the center of the earth.
Is that possible?
Obviously not. You can have a geostationary satellite, but the earth is moving so it can't be at a fixed point in the universe.
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I am not sure if I have been understood what I am asking.
I am looking for a satellite that is in a fixed point in the universe that it is in a FIXED distance and coordinates from the center of the earth.
Is that possible?
Using the surface of Earth as a coordinate system, yes it can be done as Janus and I have described. Yes, the fixed point must be over the equator. Yes, the Earth is always accelerating, so this satellite is going to accelerate with it, as pointed out by the prior post.
There is no such thing as a 'fixed point in the universe' since there is no preferred coordinate system. So you pick an arbitrary one, and the surface of Earth makes a pretty good one. It is the only coordinate system where Paris is stationary. Thus most all paper maps use this coordinate system.
Another way to do it is to put your satellite on the top of a tower, sort of like they do with cell towers. That puts it at a fixed coordinate relative to Earth. Put it on a really tall tower if you want it in space. This obviously meets your written criteria but probably misses an implied requirement for it to be in freefall.
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Is it possible to have a satellite fixed?
The Sun is moving at around 800,000 km/h around the galaxy.
- To cancel that speed, we would need to accelerate the satellite to 800,000 km/h, which is beyond our current abilities (even with multiple planetary slingshots in our solar system)
- Being stationary relative to the center of the galaxy means that the satellite will immediately start to fall directly into the SMBH in the center of our galaxy, so it still won't be stationary.
What do you want to do with your "fixed" satellite?
- That will help to determine the reference to which you wish it to be "fixed"
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We haven't been able to detect anything with a fixed location. We can not find a "fixed" reference. When we move......everything moves. And we always move.
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Hard to know what's wanted, but Lagrange points seem worth mentioning.
https://www.space.com/30302-lagrange-points.html
https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/
https://en.wikipedia.org/wiki/Lagrangian_point
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The words "fixed point in the universe" used with "fixed distance for center of earth" makes the question hard to comprehend.
What reference are you using? A fixed point in the entire universe? Galaxy? Solar system?
Or from the center of the earth, with a fixed distance?
Are the center coordinates, rotating?
How would one diagram it?