5 ms·

tl;dr: No, unless you have 200 billion nuclear bombs.

tomohelix 2y ago
Not really, the answer you are referring to is for completely stopping the moon by delivering enough energy to cancel out its current kinetic energy, of the entire moon! We don't need to stop the moon to change its orbit. With careful and deliberate adjustments via bombing and letting Earth gravity do its job, we could alter its orbit by adding to its force vector instead of trying to negate it.
- panarky 2y ago
  Applying millions of nuclear bombs to either slow down or speed up the Moon by the same amount will change its orbit by a similar magnitude in terms of the sheer change in energy. The energy required to achieve a specific Δv is the same whether you are accelerating or decelerating. This is because energy change associated with velocity (ΔE) in a conservative system is dependent on the square of the velocity change (Δv^2), regardless of direction.
- fermisea 2y ago
  Potential energy is twice the kinetic energy in a stable orbit. Changing the orbit by epsilon/r would require roughly U*epsilon/r energy. Which means that a tsar bomb would only move the moon distance to earth by 10^-10
drekipus 2y ago
This reminds me of some of the "cold war scares" that I've read about: > "If MAD happens (ie USA/RU nuclear bombing each other), then the axis of the earth would permanently be altered and every human on the planet would not be able to survive" I guess the modern era can look at that with some scrutiny; but 40, 50 years ago, that could've been a real fear?
- jghn 2y ago
  To be fair, the axis of the earth shifting wasn't a high priority in the list of fears if "MAD happens"
- andrewljohnson 2y ago
  Edward Teller wasn't sure the atomic bomb they were building wouldn't light the entire atmosphere on fire for a while there.
Intralexical 2y ago
Start by altering the orbit of a minor asteroid using a normal gravitational tug/gravity tractor. Use that to work your way up to larger and larger asteroids, until you slam Ceres into the Moon.
grecy 2y ago
All of those answers are talking about the energy required to stop the moon dead in it's tracks. What if we just wanted to slow it down 0.0000000000000000000000000000000000001% ? (which will alter it's orbit). That seems totally doable.
- kataklasm 2y ago
  We are already doing that. A orbital mechanics maneuver used in deep space spaceflight called a gravity assist or slinghshot trades a cosmic object's kinetic energy to change a spacecraft's flight path. Since that takes a large amount of energy at the speeds spacecraft go, an equal amount of energy must get subtracted from that object. Of course, the same amount of energy that's very significant for a spacecraft is meaninglessly small for an object such as a natural satellite like the Moon or a planet as Jupiter. So if you slingshot around Jupiter you are altering Jupiter's orbit around the sun an almost infinitesimally small amount, but you are altering it. But of course, the question was asking for a significantly altered orbit, which this most definitely isn't.
- gshubert17 2y ago
  Solar-powered railgun accelerating rocks to lunar escape velocity in directions chosen to make the desired delta-v. Speed the moon up or slow it down or change whatever other orbital elements you please. This would work better to change the orbit of a small asteroid. For the moon it would take (a lot) longer.

Not really, the answer you are referring to is for completely stopping the moon by delivering enough energy to cancel out its current kinetic energy, of the entire moon! We don't need to stop the moon to change its orbit. With careful and deliberate adjustments via bombing and letting Earth gravity do its job, we could alter its orbit by adding to its force vector instead of trying to negate it.

panarky 2y ago
Applying millions of nuclear bombs to either slow down or speed up the Moon by the same amount will change its orbit by a similar magnitude in terms of the sheer change in energy. The energy required to achieve a specific Δv is the same whether you are accelerating or decelerating. This is because energy change associated with velocity (ΔE) in a conservative system is dependent on the square of the velocity change (Δv^2), regardless of direction.
fermisea 2y ago
Potential energy is twice the kinetic energy in a stable orbit. Changing the orbit by epsilon/r would require roughly U*epsilon/r energy. Which means that a tsar bomb would only move the moon distance to earth by 10^-10

drekipus 2y ago

This reminds me of some of the "cold war scares" that I've read about: > "If MAD happens (ie USA/RU nuclear bombing each other), then the axis of the earth would permanently be altered and every human on the planet would not be able to survive" I guess the modern era can look at that with some scrutiny; but 40, 50 years ago, that could've been a real fear?

jghn 2y ago
To be fair, the axis of the earth shifting wasn't a high priority in the list of fears if "MAD happens"
andrewljohnson 2y ago
Edward Teller wasn't sure the atomic bomb they were building wouldn't light the entire atmosphere on fire for a while there.

Intralexical 2y ago

Start by altering the orbit of a minor asteroid using a normal gravitational tug/gravity tractor. Use that to work your way up to larger and larger asteroids, until you slam Ceres into the Moon.

grecy 2y ago

All of those answers are talking about the energy required to stop the moon dead in it's tracks. What if we just wanted to slow it down 0.0000000000000000000000000000000000001% ? (which will alter it's orbit). That seems totally doable.

kataklasm 2y ago
We are already doing that. A orbital mechanics maneuver used in deep space spaceflight called a gravity assist or slinghshot trades a cosmic object's kinetic energy to change a spacecraft's flight path. Since that takes a large amount of energy at the speeds spacecraft go, an equal amount of energy must get subtracted from that object. Of course, the same amount of energy that's very significant for a spacecraft is meaninglessly small for an object such as a natural satellite like the Moon or a planet as Jupiter. So if you slingshot around Jupiter you are altering Jupiter's orbit around the sun an almost infinitesimally small amount, but you are altering it. But of course, the question was asking for a significantly altered orbit, which this most definitely isn't.
gshubert17 2y ago
Solar-powered railgun accelerating rocks to lunar escape velocity in directions chosen to make the desired delta-v. Speed the moon up or slow it down or change whatever other orbital elements you please. This would work better to change the orbit of a small asteroid. For the moon it would take (a lot) longer.