Can planets collide and not melt together?
Ok so I've been going around on the internet trying to figure out whether or not when 2 earth like planets of similar densities and makeup collide is it possible for them to bounce off of each other or would they just smash into each other or tear each other apart?
It was pretty hard for me to find surfing the web how that would play out.
(If there's a way for a crater to form from the collision on like a continent sized scale that'd be great)
planets astrophysics
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Ok so I've been going around on the internet trying to figure out whether or not when 2 earth like planets of similar densities and makeup collide is it possible for them to bounce off of each other or would they just smash into each other or tear each other apart?
It was pretty hard for me to find surfing the web how that would play out.
(If there's a way for a crater to form from the collision on like a continent sized scale that'd be great)
planets astrophysics
New contributor
add a comment |
Ok so I've been going around on the internet trying to figure out whether or not when 2 earth like planets of similar densities and makeup collide is it possible for them to bounce off of each other or would they just smash into each other or tear each other apart?
It was pretty hard for me to find surfing the web how that would play out.
(If there's a way for a crater to form from the collision on like a continent sized scale that'd be great)
planets astrophysics
New contributor
Ok so I've been going around on the internet trying to figure out whether or not when 2 earth like planets of similar densities and makeup collide is it possible for them to bounce off of each other or would they just smash into each other or tear each other apart?
It was pretty hard for me to find surfing the web how that would play out.
(If there's a way for a crater to form from the collision on like a continent sized scale that'd be great)
planets astrophysics
planets astrophysics
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edited 3 hours ago
L.Dutch♦
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asked 3 hours ago
SlothsAndMe
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A grazing collision
If your goal is to have two planets that have collided in the past and still exist, you can make a "grazing" collision between two planets that had very different relative velocities. Basically your planet was "clipped" by a high-speed object in the past that was already moving at a high enough speed to continue on its current path without becoming gravitationally bound.
Such an impact will naturally be cataclysmic (no way is anything on the surface surviving the event) and can indeed result in a continent-sized "crater", though keep in mind that a crater of this size will not retain its "bowl" shape, but will instead fill with molten rock and solidify into a more-or-less flat "plain". The lunar "seas" are essentially continent-sized craters if you want an idea of how this will look. There is also a high chance that the collision will throw "shrapnel" all over the place and one or both planets may well wind up with a ring of ejected material.
In a grazing collision, the planets will not "bounce" off each other like billiard balls; the gravitational attraction between the two planets will be much higher than any "bounce" you get from the collision. Instead their trajectories will curve toward each other due to gravitational interaction.
add a comment |
Let's take two twin Earths. Escape velocity from Earth is 11 km/s, which means that the same velocity is what at least you can expect from an object being captured by Earth gravitational field.
This is bad news for your impact: there is no way a body the size and mass of Earth, impacting another Earth at 11 km/s, could make a gentle impact.
It is believed that the impact which generated the Moon, with a body the size of Mars, pumped so much energy into Earth to smelt once more its entire surface. And here we are talking about an even bigger body.
A molten surface is also warranty for no crater to form: any structure created by the impact will flatten out under gravity, more or less what happen to anything you do with molten chocolate.
If the density of the two bodies are different, you can have the remaining of the lightest one floating on the densest one.
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
add a comment |
Tidal forces mean devastation
Gravity is a very weak force, but planets are very big. When the two planets come within close physical proximity to each other, they will begin affecting each other gravitationally - in basically exactly the same way that the moon causes the tides. Except that the moon is about 2% the size of the Earth.
So your Earth-like planet that comes in for a collision will - when it is at lunar-orbit range - produce tidal forces approx. 50x larger than the tides today. But the distance between the Earth and the Moon is 240-ish thousand miles. The radius of the Earth itself is about 4 thousand-ish miles.
Even a near miss, where the planets never actually collide, will still have a tidal force roughly 3000 times stronger than the one we know. I'm not a geophysicist, so I can't say what exactly that will do. In general, it will not be pretty.
The collision will likely be inelastic
The large tidal force will probably be significant enough to affect the elasticity of the collision. Another thing that will affect it will be the tendency of whatever material is involved in the collision to deform, melt, and basically do a bunch of things will turn kinetic energy from the collision into something else. When that happens, it becomes much less likely that the collision will be elastic ("elastic" meaning "bouncing off like a billiary ball" in a physics context).
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3 Answers
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3 Answers
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A grazing collision
If your goal is to have two planets that have collided in the past and still exist, you can make a "grazing" collision between two planets that had very different relative velocities. Basically your planet was "clipped" by a high-speed object in the past that was already moving at a high enough speed to continue on its current path without becoming gravitationally bound.
Such an impact will naturally be cataclysmic (no way is anything on the surface surviving the event) and can indeed result in a continent-sized "crater", though keep in mind that a crater of this size will not retain its "bowl" shape, but will instead fill with molten rock and solidify into a more-or-less flat "plain". The lunar "seas" are essentially continent-sized craters if you want an idea of how this will look. There is also a high chance that the collision will throw "shrapnel" all over the place and one or both planets may well wind up with a ring of ejected material.
In a grazing collision, the planets will not "bounce" off each other like billiard balls; the gravitational attraction between the two planets will be much higher than any "bounce" you get from the collision. Instead their trajectories will curve toward each other due to gravitational interaction.
add a comment |
A grazing collision
If your goal is to have two planets that have collided in the past and still exist, you can make a "grazing" collision between two planets that had very different relative velocities. Basically your planet was "clipped" by a high-speed object in the past that was already moving at a high enough speed to continue on its current path without becoming gravitationally bound.
Such an impact will naturally be cataclysmic (no way is anything on the surface surviving the event) and can indeed result in a continent-sized "crater", though keep in mind that a crater of this size will not retain its "bowl" shape, but will instead fill with molten rock and solidify into a more-or-less flat "plain". The lunar "seas" are essentially continent-sized craters if you want an idea of how this will look. There is also a high chance that the collision will throw "shrapnel" all over the place and one or both planets may well wind up with a ring of ejected material.
In a grazing collision, the planets will not "bounce" off each other like billiard balls; the gravitational attraction between the two planets will be much higher than any "bounce" you get from the collision. Instead their trajectories will curve toward each other due to gravitational interaction.
add a comment |
A grazing collision
If your goal is to have two planets that have collided in the past and still exist, you can make a "grazing" collision between two planets that had very different relative velocities. Basically your planet was "clipped" by a high-speed object in the past that was already moving at a high enough speed to continue on its current path without becoming gravitationally bound.
Such an impact will naturally be cataclysmic (no way is anything on the surface surviving the event) and can indeed result in a continent-sized "crater", though keep in mind that a crater of this size will not retain its "bowl" shape, but will instead fill with molten rock and solidify into a more-or-less flat "plain". The lunar "seas" are essentially continent-sized craters if you want an idea of how this will look. There is also a high chance that the collision will throw "shrapnel" all over the place and one or both planets may well wind up with a ring of ejected material.
In a grazing collision, the planets will not "bounce" off each other like billiard balls; the gravitational attraction between the two planets will be much higher than any "bounce" you get from the collision. Instead their trajectories will curve toward each other due to gravitational interaction.
A grazing collision
If your goal is to have two planets that have collided in the past and still exist, you can make a "grazing" collision between two planets that had very different relative velocities. Basically your planet was "clipped" by a high-speed object in the past that was already moving at a high enough speed to continue on its current path without becoming gravitationally bound.
Such an impact will naturally be cataclysmic (no way is anything on the surface surviving the event) and can indeed result in a continent-sized "crater", though keep in mind that a crater of this size will not retain its "bowl" shape, but will instead fill with molten rock and solidify into a more-or-less flat "plain". The lunar "seas" are essentially continent-sized craters if you want an idea of how this will look. There is also a high chance that the collision will throw "shrapnel" all over the place and one or both planets may well wind up with a ring of ejected material.
In a grazing collision, the planets will not "bounce" off each other like billiard balls; the gravitational attraction between the two planets will be much higher than any "bounce" you get from the collision. Instead their trajectories will curve toward each other due to gravitational interaction.
answered 3 hours ago
IndigoFenix
14.3k12663
14.3k12663
add a comment |
add a comment |
Let's take two twin Earths. Escape velocity from Earth is 11 km/s, which means that the same velocity is what at least you can expect from an object being captured by Earth gravitational field.
This is bad news for your impact: there is no way a body the size and mass of Earth, impacting another Earth at 11 km/s, could make a gentle impact.
It is believed that the impact which generated the Moon, with a body the size of Mars, pumped so much energy into Earth to smelt once more its entire surface. And here we are talking about an even bigger body.
A molten surface is also warranty for no crater to form: any structure created by the impact will flatten out under gravity, more or less what happen to anything you do with molten chocolate.
If the density of the two bodies are different, you can have the remaining of the lightest one floating on the densest one.
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
add a comment |
Let's take two twin Earths. Escape velocity from Earth is 11 km/s, which means that the same velocity is what at least you can expect from an object being captured by Earth gravitational field.
This is bad news for your impact: there is no way a body the size and mass of Earth, impacting another Earth at 11 km/s, could make a gentle impact.
It is believed that the impact which generated the Moon, with a body the size of Mars, pumped so much energy into Earth to smelt once more its entire surface. And here we are talking about an even bigger body.
A molten surface is also warranty for no crater to form: any structure created by the impact will flatten out under gravity, more or less what happen to anything you do with molten chocolate.
If the density of the two bodies are different, you can have the remaining of the lightest one floating on the densest one.
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
add a comment |
Let's take two twin Earths. Escape velocity from Earth is 11 km/s, which means that the same velocity is what at least you can expect from an object being captured by Earth gravitational field.
This is bad news for your impact: there is no way a body the size and mass of Earth, impacting another Earth at 11 km/s, could make a gentle impact.
It is believed that the impact which generated the Moon, with a body the size of Mars, pumped so much energy into Earth to smelt once more its entire surface. And here we are talking about an even bigger body.
A molten surface is also warranty for no crater to form: any structure created by the impact will flatten out under gravity, more or less what happen to anything you do with molten chocolate.
If the density of the two bodies are different, you can have the remaining of the lightest one floating on the densest one.
Let's take two twin Earths. Escape velocity from Earth is 11 km/s, which means that the same velocity is what at least you can expect from an object being captured by Earth gravitational field.
This is bad news for your impact: there is no way a body the size and mass of Earth, impacting another Earth at 11 km/s, could make a gentle impact.
It is believed that the impact which generated the Moon, with a body the size of Mars, pumped so much energy into Earth to smelt once more its entire surface. And here we are talking about an even bigger body.
A molten surface is also warranty for no crater to form: any structure created by the impact will flatten out under gravity, more or less what happen to anything you do with molten chocolate.
If the density of the two bodies are different, you can have the remaining of the lightest one floating on the densest one.
answered 3 hours ago
L.Dutch♦
76.8k25183374
76.8k25183374
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
add a comment |
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
The impact that generated the Moon may have happened at 4km/s. Still, smaller bodies, smaller velocities, and it probably reset the Hadean, so...
– Renan
24 mins ago
add a comment |
Tidal forces mean devastation
Gravity is a very weak force, but planets are very big. When the two planets come within close physical proximity to each other, they will begin affecting each other gravitationally - in basically exactly the same way that the moon causes the tides. Except that the moon is about 2% the size of the Earth.
So your Earth-like planet that comes in for a collision will - when it is at lunar-orbit range - produce tidal forces approx. 50x larger than the tides today. But the distance between the Earth and the Moon is 240-ish thousand miles. The radius of the Earth itself is about 4 thousand-ish miles.
Even a near miss, where the planets never actually collide, will still have a tidal force roughly 3000 times stronger than the one we know. I'm not a geophysicist, so I can't say what exactly that will do. In general, it will not be pretty.
The collision will likely be inelastic
The large tidal force will probably be significant enough to affect the elasticity of the collision. Another thing that will affect it will be the tendency of whatever material is involved in the collision to deform, melt, and basically do a bunch of things will turn kinetic energy from the collision into something else. When that happens, it becomes much less likely that the collision will be elastic ("elastic" meaning "bouncing off like a billiary ball" in a physics context).
add a comment |
Tidal forces mean devastation
Gravity is a very weak force, but planets are very big. When the two planets come within close physical proximity to each other, they will begin affecting each other gravitationally - in basically exactly the same way that the moon causes the tides. Except that the moon is about 2% the size of the Earth.
So your Earth-like planet that comes in for a collision will - when it is at lunar-orbit range - produce tidal forces approx. 50x larger than the tides today. But the distance between the Earth and the Moon is 240-ish thousand miles. The radius of the Earth itself is about 4 thousand-ish miles.
Even a near miss, where the planets never actually collide, will still have a tidal force roughly 3000 times stronger than the one we know. I'm not a geophysicist, so I can't say what exactly that will do. In general, it will not be pretty.
The collision will likely be inelastic
The large tidal force will probably be significant enough to affect the elasticity of the collision. Another thing that will affect it will be the tendency of whatever material is involved in the collision to deform, melt, and basically do a bunch of things will turn kinetic energy from the collision into something else. When that happens, it becomes much less likely that the collision will be elastic ("elastic" meaning "bouncing off like a billiary ball" in a physics context).
add a comment |
Tidal forces mean devastation
Gravity is a very weak force, but planets are very big. When the two planets come within close physical proximity to each other, they will begin affecting each other gravitationally - in basically exactly the same way that the moon causes the tides. Except that the moon is about 2% the size of the Earth.
So your Earth-like planet that comes in for a collision will - when it is at lunar-orbit range - produce tidal forces approx. 50x larger than the tides today. But the distance between the Earth and the Moon is 240-ish thousand miles. The radius of the Earth itself is about 4 thousand-ish miles.
Even a near miss, where the planets never actually collide, will still have a tidal force roughly 3000 times stronger than the one we know. I'm not a geophysicist, so I can't say what exactly that will do. In general, it will not be pretty.
The collision will likely be inelastic
The large tidal force will probably be significant enough to affect the elasticity of the collision. Another thing that will affect it will be the tendency of whatever material is involved in the collision to deform, melt, and basically do a bunch of things will turn kinetic energy from the collision into something else. When that happens, it becomes much less likely that the collision will be elastic ("elastic" meaning "bouncing off like a billiary ball" in a physics context).
Tidal forces mean devastation
Gravity is a very weak force, but planets are very big. When the two planets come within close physical proximity to each other, they will begin affecting each other gravitationally - in basically exactly the same way that the moon causes the tides. Except that the moon is about 2% the size of the Earth.
So your Earth-like planet that comes in for a collision will - when it is at lunar-orbit range - produce tidal forces approx. 50x larger than the tides today. But the distance between the Earth and the Moon is 240-ish thousand miles. The radius of the Earth itself is about 4 thousand-ish miles.
Even a near miss, where the planets never actually collide, will still have a tidal force roughly 3000 times stronger than the one we know. I'm not a geophysicist, so I can't say what exactly that will do. In general, it will not be pretty.
The collision will likely be inelastic
The large tidal force will probably be significant enough to affect the elasticity of the collision. Another thing that will affect it will be the tendency of whatever material is involved in the collision to deform, melt, and basically do a bunch of things will turn kinetic energy from the collision into something else. When that happens, it becomes much less likely that the collision will be elastic ("elastic" meaning "bouncing off like a billiary ball" in a physics context).
answered 2 hours ago
Dayton Williams
1,429313
1,429313
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SlothsAndMe is a new contributor. Be nice, and check out our Code of Conduct.
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