Pictures of Moon's Surface.

G=EMC^2 Glazier wrote:
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both? With
Moons less gravity,and no atmosphere how low can we put a satellite in
orbit? Could we place it 36,000 feet up? I've seen the Earth at that
height. Bert

The only things that determine how low a Moon orbit can be are the tallest
mountains out there - you wouldn't want to crash into one of them! :-)

--
The butler did it.

(G=EMC^2 Glazier) wrote in message ...
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both? With
Moons less gravity,and no atmosphere how low can we put a satellite in
orbit? Could we place it 36,000 feet up? I've seen the Earth at that
height. Bert

We do have both. All you have to do is get a telescope and look at
the moon iwth it. Its enjoyable, although I doubt you will see any
changes there. With Mars, we have two orbiting spacecraft keeping
tabs on Mars, as well as another on the way. As for how low you can
go in orbit around the moon, it can be pretty low, but such low orbits
are a bit unstable and space probes in such orbits will need to do
occasional corrections to maintain the orbits and keep from crashing
into a high mountain peak or crater rim. However, such low orbits are
really unneeded, as a long-lens will get the resolution high enough to
see even meter-sized detail on the surface.

David Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org

(G=EMC^2 Glazier) wrote in message ...
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both? With
Moons less gravity,and no atmosphere how low can we put a satellite in
orbit? Could we place it 36,000 feet up? I've seen the Earth at that
height. Bert

We do have both. All you have to do is get a telescope and look at
the moon iwth it. Its enjoyable, although I doubt you will see any
changes there. With Mars, we have two orbiting spacecraft keeping
tabs on Mars, as well as another on the way. As for how low you can
go in orbit around the moon, it can be pretty low, but such low orbits
are a bit unstable and space probes in such orbits will need to do
occasional corrections to maintain the orbits and keep from crashing
into a high mountain peak or crater rim. However, such low orbits are
really unneeded, as a long-lens will get the resolution high enough to
see even meter-sized detail on the surface.

David Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org

"Ugo" wrote in message ...
G=EMC^2 Glazier wrote:
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both? With
Moons less gravity,and no atmosphere how low can we put a satellite in
orbit? Could we place it 36,000 feet up? I've seen the Earth at that
height. Bert

The only things that determine how low a Moon orbit can be are the tallest
mountains out there - you wouldn't want to crash into one of them! :-)

It's a little harder than that, because the moon is gravitationally
lumpy. It's uneven enough, internally, that orbits noticeably don't
follow exact ellipses -- the moon landings had to watch out for the
lumpy gravity pushing them in places they didn't quite expect. You
don't want to shave it too close, because the lumpiness will have
negative repercussions for the stability of a close-in orbit.

eyelessgame

"Ugo" wrote in message ...
G=EMC^2 Glazier wrote:
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both? With
Moons less gravity,and no atmosphere how low can we put a satellite in
orbit? Could we place it 36,000 feet up? I've seen the Earth at that
height. Bert

The only things that determine how low a Moon orbit can be are the tallest
mountains out there - you wouldn't want to crash into one of them! :-)

It's a little harder than that, because the moon is gravitationally
lumpy. It's uneven enough, internally, that orbits noticeably don't
follow exact ellipses -- the moon landings had to watch out for the
lumpy gravity pushing them in places they didn't quite expect. You
don't want to shave it too close, because the lumpiness will have
negative repercussions for the stability of a close-in orbit.

eyelessgame

eyelessgame wrote:
"Ugo" wrote in message
...
G=EMC^2 Glazier wrote:
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both?
With Moons less gravity,and no atmosphere how low can we put a
satellite in orbit? Could we place it 36,000 feet up? I've seen the
Earth at that height. Bert

The only things that determine how low a Moon orbit can be are the
tallest mountains out there - you wouldn't want to crash into one of
them! :-)

It's a little harder than that, because the moon is gravitationally
lumpy. It's uneven enough, internally, that orbits noticeably don't
follow exact ellipses -- the moon landings had to watch out for the
lumpy gravity pushing them in places they didn't quite expect. You
don't want to shave it too close, because the lumpiness will have
negative repercussions for the stability of a close-in orbit.

Hm, I never thought that would be a major issue... Now, I have a couple of
questions. Exactly how pronounced is this effect? Compared to Earth, is Moon
lumpier or less lumpy (not that this matters for Earth, but just as a
comparison)? These deviations from exact ellipses, what magnitude are we
talking about here (say for a very low orbit) - order of tens, hundreds or
thousands of meters? Also, is this lumpiness directed nadir, or does it also
act sideways, changing orbit inclination?

--
The butler did it.

eyelessgame wrote:
"Ugo" wrote in message
...
G=EMC^2 Glazier wrote:
David I like the Hubble to view deep space,and I like the idea of
keeping a close up view of Mars surface. Why can't we have both?
With Moons less gravity,and no atmosphere how low can we put a
satellite in orbit? Could we place it 36,000 feet up? I've seen the
Earth at that height. Bert

The only things that determine how low a Moon orbit can be are the
tallest mountains out there - you wouldn't want to crash into one of
them! :-)

It's a little harder than that, because the moon is gravitationally
lumpy. It's uneven enough, internally, that orbits noticeably don't
follow exact ellipses -- the moon landings had to watch out for the
lumpy gravity pushing them in places they didn't quite expect. You
don't want to shave it too close, because the lumpiness will have
negative repercussions for the stability of a close-in orbit.

Hm, I never thought that would be a major issue... Now, I have a couple of
questions. Exactly how pronounced is this effect? Compared to Earth, is Moon
lumpier or less lumpy (not that this matters for Earth, but just as a
comparison)? These deviations from exact ellipses, what magnitude are we
talking about here (say for a very low orbit) - order of tens, hundreds or
thousands of meters? Also, is this lumpiness directed nadir, or does it also
act sideways, changing orbit inclination?

--
The butler did it.

Ugo,
A web search under 'lunar mascon' will turn up all you ever
wanted to know about the moon's gravity anomalies. Mascon is short for
'mass concentration'. oc

Ugo,
A web search under 'lunar mascon' will turn up all you ever
wanted to know about the moon's gravity anomalies. Mascon is short for
'mass concentration'. oc