Thread: why aren't artificial satellites tidally locked?

as i understand it most satellites are facing either towards or away from the earth and dont rotate

but tidal locking should make this happen, right?

As far as i think mostly satellites rotate along the earth from west to east because they are geostationary satellites, they're synchronized to earths 24 hr period. That's what i think !!!! 8)

Also, some satelites are not geosynchronis, such as satelites used to map out the surface of the planet. They are placed so as to be over different points of the planet at different times, unlike a communication satelite. or the ISS is in orbit, but it is not geosynchronis. Not sure what you mean by "tidally Locked" though. The satelites are "rotating" in relation to the sun, but they are fixed toward or away from the planet just as the moon has only one side facing the planet, but it is rotating in relation to the sun.

yes but the moon is tidally locked to the earth, that is to say it rotates right along with the earth

geosynchronous satellites would make sense not to rotate, but other satellites should be forced to rotate by the earths gravity

Medlakeguy,

I believe you are referring to spin more so than rotation. It's quite a vage term to use in this context.

Perhaps this will clarify things;

Objects in space are ORBITING the planet. The are NOT spinning while orbit. The moon is orbiting the earth and the earth the sun. But the earth is also spinning and the moon is in sync with this spin, hence why we never the far side of the moon.

The moon is not spinning AT ALL. It always has one side turned to the Earth. and is orbiting around the earth whereas the Earth is constantly spinning.

Maybe this clarifies things a little.

Barry

Originally Posted by medlakeguy

yes but the moon is tidally locked to the earth, that is to say it rotates right along with the earth

geosynchronous satellites would make sense not to rotate, but other satellites should be forced to rotate by the earths gravity

Geosynchronous communication's satellites are just like the moon, one side always faces the planet.

Originally Posted by Barry Flannery

Medlakeguy,

I believe you are referring to spin more so than rotation. It's quite a vage term to use in this context.

Perhaps this will clarify things;

Objects in space are ORBITING the planet. The are NOT spinning while orbit. The moon is orbiting the earth and the earth the sun. But the earth is also spinning and the moon is in sync with this spin, hence why we never the far side of the moon.

The moon is not spinning AT ALL. It always has one side turned to the Earth. and is orbiting around the earth whereas the Earth is constantly spinning.

Maybe this clarifies things a little.

Barry

come to think of it rotate was a little vague... of course spin could be misconstrued in the same way

i was under the impression that the moon was spinning, just in sync with the earth so one side is always facing the night sky... ill look into it


EDIT: found this, looks like i was right

In fact the Moon *does* rotate: It rotates exactly once for every
orbit it makes about the Earth. The fact that the Moon is rotating
may seem counterintuitive: If it's always facing towards us, how can
it be rotating at all? To see how this works, put two coins on a
table, a large one to represent the Earth, and a small one to
represent the Moon. Choose a particular place on the edge of the
"Moon" as a reference point. Now, move the Moon around the Earth in a
circle, but be careful to always keep the spot you picked pointed at
the Earth (this is analogous to the Moon always keeping the same face
pointed at the Earth). You should notice that as you do this, you
have to slowly rotate the Moon as it circles the Earth. By the time
the Moon coin goes once around the Earth coin, you should have had to
rotate the Moon exactly once.

Omn a side not, as far as I am aware all (most/many) satellites have to spin in order to prevent excessive temperature contrasts across the satellite.