What causes a satellite's orbit to decay?

My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Is our moon's orbit decaying?

Is the Moon not in some sort of dynamic equilibrium? That would be with
the Earth and the rest of the soalrSystem?





Chris Wood wrote:

My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Is our moon's orbit decaying?

Is the Moon not in some sort of dynamic equilibrium? That would be with
the Earth and the rest of the soalrSystem?





Chris Wood wrote:

My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Is our moon's orbit decaying?

Chris Wood wrote:
My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Yes, you guessed right. The lower the orbit is, the faster the decay is. The
densitiy of the upper layers of the atmosphere varies significantly with
solar activity, so it's practically impossible to predict.


Is our moon's orbit decaying?

No, the Moon is just too far from Earth to be affected by this (some 60
Earth radii). In fact, the Moon is actually moving farther from us due to
tidal interactions
with Earth!

--
The butler did it.

Chris Wood wrote:
My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Yes, you guessed right. The lower the orbit is, the faster the decay is. The
densitiy of the upper layers of the atmosphere varies significantly with
solar activity, so it's practically impossible to predict.


Is our moon's orbit decaying?

No, the Moon is just too far from Earth to be affected by this (some 60
Earth radii). In fact, the Moon is actually moving farther from us due to
tidal interactions
with Earth!

--
The butler did it.

"V35B" wrote in message
...
Is the Moon not in some sort of dynamic equilibrium? That would be with
the Earth and the rest of the soalrSystem?

Chris Wood wrote:

My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Is our moon's orbit decaying?

Two things -

Close satellites are descending as the high atmosphere causes conversion of
orbital energy to atmospheric kinetic energy.

The moon is ascending due to conversion of tidal energy to orbital energy.

"V35B" wrote in message
...
Is the Moon not in some sort of dynamic equilibrium? That would be with
the Earth and the rest of the soalrSystem?

Chris Wood wrote:

My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Is our moon's orbit decaying?

Two things -

Close satellites are descending as the high atmosphere causes conversion of
orbital energy to atmospheric kinetic energy.

The moon is ascending due to conversion of tidal energy to orbital energy.

"Chris Wood" wrote in message ...
My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Yes, especially for low-orbit satellites.

Is our moon's orbit decaying?

No. The moon is receding.

Satellites in danger of decay are about 350-500 km up; a very thin
envelope of atmosphere extends that far.

By the time one gets to geosync orbit (~36000 km), satellites aren't
noticeably decaying.

The moon is 400000 km away. There is no detectable atmospheric drag
on the moon.

On the other hand, the moon's tidal friction force on the Earth does
push it into a gradually higher orbit, at about the same velocity as
your fingernails grow.

"Chris Wood" wrote in message ...
My guess is that the orbit of a man-made
satellite circling the earth might decay because
of residual air molecules causing friction.

Is this true?

Yes, especially for low-orbit satellites.

Is our moon's orbit decaying?

No. The moon is receding.

Satellites in danger of decay are about 350-500 km up; a very thin
envelope of atmosphere extends that far.

By the time one gets to geosync orbit (~36000 km), satellites aren't
noticeably decaying.

The moon is 400000 km away. There is no detectable atmospheric drag
on the moon.

On the other hand, the moon's tidal friction force on the Earth does
push it into a gradually higher orbit, at about the same velocity as
your fingernails grow.

Close satellites are descending as the high atmosphere causes conversion of
orbital energy to atmospheric kinetic energy.

The moon is ascending due to conversion of tidal energy to orbital energy.

Is not the Earth-Moon system ascending from solar orbit also? for similar
reasons? And how about the billions of tons of mass per second the sun is
losing? - Less mass means less gravity, which means expanding orbits, right?


Halloween Survey
http://members.aol.com/RichClark7/rev/hallowen.htm