if the moon were collapsed to a black hole, would the orbit change?
952700
As you probably already know, you just can't get a black hole without a certain amount of mass.\n\nBut if this is science fiction, and you wanted to just posit that you could make a moon-massed black hole, then for the most part, the moon would act the same.  If you were, say, navigating around a black hole, you wouldn't treat it any differntly from a star of the same mass.  Things only get wonky one you break the event horizon.  But outside of that, your moon hole would just act like a dark moon-massed object.\n\nAs far as Hawking radiation, if I remember correctly, Hawking suggested that it might be possible for mini-black holes to have formed in the beginning of the universe, and they might have masses less than a standard black hole.  And I think he did suggest that the smaller the black hole is, the faster it evaporates due to Hawking radiation.  So it would not be a huge stretch to say that your moon-sized black whole could dissipate quickly.
345783
Yes, black holes can move in space,\npartially due to the law of conservation of momentum (and inertia), if it was moving before it became a black hole, it will continue to move,\nand a black hole is affected by gravity like other objects.\n\nIt has been theorized, and some experimental evidence confirms, that larger (super-massive) black holes reside within many galaxy's centers.  As we can observe, galaxies can, and do, move around...thus if they have a black hole at thier center, the black hole moves as well.
651257
The immediate effect would be no tides and no large area of high atmospheric pressure toward the moon.  The long-term effect would be the end of life on Earth.  The moon holds the earth's tilt to a small range of precession.  A wobble of only 0.5 degrees created the Sahara desert 6,000 years ago.  Planets with no large moon wobble by 30 degrees or more.  It would cause a climate shifting catastrophe.  Imagine if Texas  received 6 months of sunlight like the north pole.
637323
The Sun does rotate/turn on an axis by itself, but it also rotates around a huge black hole in the center of our galaxy, and it takes a very, very, VERY long time to complete one rotation.\n\nIt rotates around the black hole with similar principles to that of earth revolving around the sun, and yes, eventually it will be swallowed by the black hole.
486631
Assuming this is possible the end positioned inside the event horizon would be broken down into it's individual atoms and would cease to exist.  However some scientists (me being one of them) think black holes are only one end of a worm hole and that when you reach the event horizon you are expelled out of a white hole into another universe.  Think of a white hole as the polar opposite of a black hole, instead of consuming every thing it expels everything
30684
Yes - the moon is far away, and the earth spins around it's own axis, creating day and night time. The moon would move a little 1/56 of phase shift during the half day it would take for the other half of earth to see the moon, but it's not noticeable.
631703
Black holes aren't holes in the sense that you're thinking of. A black hole is a region of spacetime (it has 3+1 dimensions like everything else) that has an event horizon (a spherical region) that nothing can escape from.\nTaking the rubber sheet analogy (this is 2+1 dimensional, two spatial dimensions, 1 time dimension), suppose there is a spherical mass placed on the stretched sheet. Depending on how massive that mass is, the sheet around the mass will be circularly distorted, creating a potential energy well. You can roll smaller masses by it. If you roll the smaller mass with too little tangent velocity, it will spiral into the larger mass. If you roll it with a great enough tangential velocity, it may change direction, but it will go right through the potential energy well.\nA black hole has a certain region of its potential energy well (the region inside the event horizon) where no velocity you give a particle will be enough to get it back out of the energy well; all particles entering the event horizon will spiral into the singularity at the center. Part of the reason for this is the limit placed on massive particle accelerations of only being able to accelerate up to the speed of light in vacuum. It is interesting to note that outside the event horizon (assuming a non-spinning black hole), gravity behaves classically. Ie., if the Sun were to collapse into a black hole (which it doesn't have the mass to do), the radius of its event horizon would be less than the current radius of the Sun, so the solar system would continue as usual; the gravitational field outside the event horizon is unchanged.\nAlso, a black hole need not be caused by the death of a star. Primordial black holes are hypothesized to be black holes that formed during the chaotic spacetime of the early universe.
1142803
First off, that a black hole sucks everything around it in is basically a myth.  The pull of a black hole at a distance r>Rhorizon is equal to the pull of any other equally massive spherical object.  So if the sun collapsed into a black hole, ignoring the fact  that it's not nearly massive enough (by a factor of 10), we would still feel the same pull of gravity and remain in the same orbit.  That said, in a quickly rotating black hole, there is an inner horizon where the inescapable fall towards the singularity at  the center of the black hole is halted.  Inside this second horizon space remains spacelike, meaning time travel is possible, unfortunately escape from this inner horizon is impossible because there is still the area between the inner and outer horizon which is one directional and impossible to penetrate.
863481
A black hole is just like any other star or planet. \n\nThe larger the body's mass, the greater its gravity pull. That's why the lunar astronauts could bounce along on the moons surface, the gravity there is much lower than on Earth as the moon is much smaller.\n\nOur sun's gravity is enough to keep all the planets in their orbits.\n\nA black hole was a very large star, with high gravity, so high that when it ran out of fuel, it collapsed in on itself. Because the material making up this star is now concentrated down to such a degree that the gravity near it is so strong even light cannot escape, we call it a black hole.\n\nIf something is sucked into it, the mater does not go anywhere, it just gets squashed into the same place as all the other material making up the black hole.
527942
i can tell u what would happen if we had no moon... this is the answer... \n\n\nIf the Moon did escape from Earth, the main effect would be the lack of tides on Earth. Tides are caused by the differential gravitational force on the equatorial regions: i.e. the region closer to the Moon experiences more gravitational force than the region on Earth away from the Moon. This results in the formation of high and low tides on different regions of the Earth. \n\nOther than tidal forces, there is no other geological or climatic influence of the Moon on Earth. There are issues like no more Moon to light up the night sky, no more solar eclipses, etc. but there will be no change in the geology or climate on Earth.
1108101
Yes, but not one that you could appreciate.\n\nAs you approach a black hole you would be ripped apart on a molecular level.\n\nThen, after you got in there in several pieces, you would be in stasis until sometime WAY WAY WAY in the future when it exploded.\n\nThen you would have to wait for a few billion years for something to evolve that would resemble something you would be comfortable with.
422733
yes it would affect the earth because it would disrupt our tides and all of our weather would either become very extreme or nonexistent also we wouldn't have a moon for any one else to visit and then we wouldn't be able to go to anywhere but the earth .
414408
Yes, the radius of the moon's orbit is currently increasing by about 3.8 cm (about 1.5 inches) every year.  This happens because the moon raises tides on the Earth.  Because the Earth rotates faster than the moon orbits the Earth, the tidal "bulge" of the Earth on the side nearest the moon actually leads, or is in front of, the position of the moon in its orbit (see diagrams in sources given below). That "extra" mass of the Earth's tidal bulge acts to accelerate the moon in its orbit, increasing its angular momentum, and causing the moon's orbit to "spiral out" over time.  Because the angular momentum of the Earth-moon system must be conserved, the Earth's angular momentum must decrease to balance the increase in the moon's momentum, slowing the Earth's rotation rate by a bit (currently, about 15 microseconds/year).  \n\nThese rates have changed over geologic time because the position of the tidal bulge relative to the line connecting the Earth and moon depends on, among other things, the arrangement of continents and oceans on Earth.  These affect the friction affecting the tidal bulge, and therefore its velocity relative to the Earth's rotational velocity.\n\nThe energy of the Earth-moon system must also be conserved, and because the moon gets further from the Earth, its potential energy increases.  Consequently, it's kinetic energy must decrease by an amount exactly equal to the increase in potential energy.  Because the kinetic energy of the moon (or any other object) is proportional to the square of the velocity, the moon's velocity in its orbit is decreasing.\n\nThis process will continue until the moon's orbital period and the Earth's rotational period are equal, at which point the moon and Earth will be "tidally locked", with the same side of each body facing the other body at all times.\n\nThe story doesn't stop here, though.  The Earth-moon system loses angular momentum to the (Earth/moon)-sun system, resulting in an increase in the distance of the center of mass of the Earth+moon from the sun.  This is occurring today, but is a much smaller effect than the lunar tidal effect discussed above.  Once the Earth and moon are tidally locked, though, it will become the dominant effect. As a consequence, the moon's orbital radius will slowly *decrease* until the moon gets somewhere within the Roche limit, at which point (assuming the sun has not become a red giant and expanded beyond the orbit of the Earth by then!) the moon will break apart, most likely forming a ring system around the Earth.\n\nThe Roche limit is the distance from a parent body at which the difference between the gravitational force on a a satellite's near side and a satellite's far side exceeds the gravitational self attraction of the satellite.  Because the moon is made of rock, it has some cohesive strength (i.e., the moon is not just held together by self-gravitation) that will allow it to come within the true Roche limit before being disrupted.
512600
I'd see a waning gibbous moon.\n\nOur sentiments play tricks on us to make us think the moon is rarer than it used to be.  But it's been revolving around the earth for a very long time.
801410
a mile wide crater on the moon, and a slight change in orbit depending on the momentum of the asteroids
709262
Don't forget that large bodies like the earth itself, and the sun, are themselves held together with gravity.\n\nProbably the first thing that we would notice is that the earth would immediately lose its atmosphere as it went flying off the planet into space, as would the oceans.  Everything on the surface of the planet would go flying off due to the centrifugal force of its spinning ... buildings would just rip off their foundations like cheese shaking off a cheese-puff.  Without an atmosphere, it's doubtful you and I would live more than 15 or 30 seconds.\n\nThe earth  would immediately break apart in a big cloud of hot liquid iron (the core of the earth) and all the stuff on the surface.\n\nThe moon would also disolve into a huge cloud of hot rocks and sand.\n\nThe sun would explode rather violently, as the pressure from the burning of the inner core would suddenly have no force counteracting it.  The same would be happening to every star and planet in the universe.  And galaxies themselves would fly apart (as they too are held together with gravity).\n\nAnd yes, what is left of the earth would fly away from what is left of the sun ... although it would be quickly overtaken by the exploding sun.\n\nBut, of course, it ain't gonna happen.  I'll bet everything I own on it.  :-)  \n\nThink of this as a great way to get back in with your girlfriend ... "Hey baby, if gravity were suddenly to disappear, we need to be holdin' each other really tight!"  (You take it from there).
140176
The Sun, Earth, and Moon are all gravitationally tied together. In other words, the interaction of their individual gravitational fields closely relates one to the other. The Earth/Moon system moves around the Sun in a particular orbit. Should the Sun somehow disappear, the movement of the Earth/Moon system would be radically altered. Even the Sun, the largest mass of the three objects, has its movement through space influenced by the gravity of the Earth and Moon. If we could view our Sun from several light years away, we'd notice that it moves through space not in a straight line, but instead a wavy line as the Earth/Moon system tugs at it.