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Would turning the planet Mercury into a giant mirror be a good way to heat the outer solar system?
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If you could deflect most of the light off planet Mercury and to a focused point in the sky, for example, could you heat up a planet like Neptune? You could also start this process at the poles where it is a comfortable temperature for humans.
Is this a crazy idea or has there been any thought around it? Enlighten me.
solar-system
edited 7 hours ago
Michael Kjörling♦
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asked 12 hours ago
Shane Mulligan
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up vote
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If you could deflect most of the light off planet Mercury and to a focused point in the sky, for example, could you heat up a planet like Neptune? You could also start this process at the poles where it is a comfortable temperature for humans.
Is this a crazy idea or has there been any thought around it? Enlighten me.
solar-system
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
asked 12 hours ago
Shane Mulligan
271
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Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
5
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago
add a comment |Â
up vote
4
down vote
favorite
up vote
4
down vote
favorite
If you could deflect most of the light off planet Mercury and to a focused point in the sky, for example, could you heat up a planet like Neptune? You could also start this process at the poles where it is a comfortable temperature for humans.
Is this a crazy idea or has there been any thought around it? Enlighten me.
solar-system
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
asked 12 hours ago
Shane Mulligan
271
New contributor
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
If you could deflect most of the light off planet Mercury and to a focused point in the sky, for example, could you heat up a planet like Neptune? You could also start this process at the poles where it is a comfortable temperature for humans.
Is this a crazy idea or has there been any thought around it? Enlighten me.
solar-system
solar-system
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
asked 12 hours ago
Shane Mulligan
271
New contributor
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
asked 12 hours ago
Shane Mulligan
271
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Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
edited 7 hours ago
Michael Kjörling♦
21.1k1085163
21.1k1085163
asked 12 hours ago
Shane Mulligan
271
New contributor
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 12 hours ago
Shane Mulligan
271
asked 12 hours ago
Shane Mulligan
271
271
New contributor
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Shane Mulligan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
5
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago
add a comment |Â
"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
5
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago
"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
5
5
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago
add a comment |Â
5 Answers
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No
Reflecting and focusing light requires a strict control on the geometry of the system.
What you need to deflect light hitting Mercury and focus it on Neptune is an adaptive parabolic mirror with adjustable focal length in a working range of millions of kilometers.
Even if that was possible, you would still have two major problems to overcome:
- The Sun covering Mercury as seen from Neptune for roughly half of the time
- Mercury being flimsy in comparison to Neptune (see image, courtesy of this site). Mercury is the one at the bottom right.
answered 11 hours ago
L.Dutch♦
62.2k18144291
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Kind of related to your question - there have been several proposals in the past for the use of giant space mirrors. The idea however, was to cool down the planet by blocking a portion of the incoming sunlight. One was proposed as a way to combat global warming, and the idea was also proposed to start terraforming Venus.
There was also a project called Znamya which was a Russian project using a space-based mirror. A prototype was successfully deployed - the idea was to help boost solar production on the ground by increasing the sunlight.
If you wanted to warm up a planet or moon in the outer solar system, a better approach might be to park giant mirrors close to the target, to catch and concentrate more of the weak solar energy. That way you don't have to worry about further diffusion and aiming.
However, a giant parabolic or slightly curved mirror might be able to focus a beam of sunlight and send it into the outer solar system without dispersing. You'd have to keep re-orientating the mirror to aim it though, as you're trying to hit a moving target.
answered 11 hours ago
Chromane
1,889320
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
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No, because the tidal forces are too high.
Because the planet Mercury is so close to the Sun, it experiences enormous tidal forces, about 17 times stronger than the moon's effect on the Earth. Furthermore, the planet's orbit is eccentric, so these tidal forces vary. The forces are so strong that Mercury's spin is 3:2 tidally locked to the Sun (i.e. 3 rotations about the planet's axis for every 2 orbits around the Sun).
Venus and Mars lack a magnetic field because their cores cooled billions of years ago. Mercury ought to be this way, too, but it's not. Mercury's tidal forces are also strong enough to keep the planet's iron core molten and flowing, giving the planet a magnetic field. Think about this: the tidal forces are strong enough to melt iron.
Whether your mirror is built on top of Mercury, built by the material of Mercury, or just in the same orbit of Mercury, it will experience these tidal forces. In the worst case, the tidal forces will tear apart your mirror. In the best case, they will deform the mirror so it no longer produces a collimated beam. The light from your mirror will be no more concentrated than the light directly from the Sun.
answered 11 hours ago
Dr Sheldon
473114
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No, because you cannot gather light
As I wrote in this answer, you cannot actually gather light. You cannot gather light from a wide cone, and then send it out into a thin beam. Whatever the angle was that you collected light from, what you emit cannot be a more narrow angle than that, if you are using only optics (i.e. refraction and reflection).
This is called Conservation of Étendue and xkcd has a better write-up of that than I can produce.
Mercury is at about 0.4 AU from the sun, while Neptune is at 30 AU. 30/0.4 = 75. This means that whatever light you reflect off of Mercury, when it reaches Neptune that light covers an area that is 75 time larger than the Sun, in effect 75 times weaker per unit of surface area than what hits Mercury.
Also The Sun has a surface area that is about 80 000 times as large as that of Mercury, so now we are down by a factor of 6 000 000.
So no... this just is not worth the effort at all.
answered 9 hours ago
MichaelK
34.5k584146
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
 |Â
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As everyone else said, there is no scientifically solid way to effectively reflect a sufficient amount of light from Mercury to Saturn.
But you're in luck since Russian scientists already found a solution to your problem: Project Znamya (meaning "Banner) they constructed a 65-foot-wide sheet of mylar that could be unfurled from a central mechanism and launched from the Mir space station.
They basically sent a giant mirror in orbit around Earth, in your case it would be orbiting around Saturn or its satellites.
The experiment did in fact work but to have a system that could actually be used to lit up the whole planet they still had a long way ahead
First of all the size of the mirror
The plan was to first test a 65-foot mirror (Znamya 2), then a 82-foot
version (Znamya 2.5), finalize the test phase with a 230-foot mirror
(Znamya 3), and, eventually launch a permanent 656-foot space mirror
installation that would be capable of fully turning early night in
Russian cities into something close to full-blown day.
And then the scale of the system
"The scheme called for a chain of many satellites to be placed in
sun-synchronized orbits at an altitude of 1700 kilometers, each one
equipped with fold-out parabolic reflectors of paper-thin material,"
Crary writes. "Once fully extended to 200 meters in diameter, each
mirror satellite would have the capacity to illuminate a
ten-square-mile area on earth with a brightness nearly 100 times
greater than moonlight."
And we're talking about Earth. Saturn has diameter 9.5 times bigger than our planet and a surface 83 times bigger. So of course your satellites will need to be way more that what you'd use to lit up Earth and probably bigger as well.
For a more in depth article: The Man Who Turned Night Into Day
answered 6 hours ago
Bolza
1395
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5 Answers
5
active
oldest
votes
5 Answers
5
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
No
Reflecting and focusing light requires a strict control on the geometry of the system.
What you need to deflect light hitting Mercury and focus it on Neptune is an adaptive parabolic mirror with adjustable focal length in a working range of millions of kilometers.
Even if that was possible, you would still have two major problems to overcome:
- The Sun covering Mercury as seen from Neptune for roughly half of the time
- Mercury being flimsy in comparison to Neptune (see image, courtesy of this site). Mercury is the one at the bottom right.
answered 11 hours ago
L.Dutch♦
62.2k18144291
add a comment |Â
up vote
4
down vote
No
Reflecting and focusing light requires a strict control on the geometry of the system.
What you need to deflect light hitting Mercury and focus it on Neptune is an adaptive parabolic mirror with adjustable focal length in a working range of millions of kilometers.
Even if that was possible, you would still have two major problems to overcome:
- The Sun covering Mercury as seen from Neptune for roughly half of the time
- Mercury being flimsy in comparison to Neptune (see image, courtesy of this site). Mercury is the one at the bottom right.
answered 11 hours ago
L.Dutch♦
62.2k18144291
add a comment |Â
up vote
4
down vote
up vote
4
down vote
No
Reflecting and focusing light requires a strict control on the geometry of the system.
What you need to deflect light hitting Mercury and focus it on Neptune is an adaptive parabolic mirror with adjustable focal length in a working range of millions of kilometers.
Even if that was possible, you would still have two major problems to overcome:
- The Sun covering Mercury as seen from Neptune for roughly half of the time
- Mercury being flimsy in comparison to Neptune (see image, courtesy of this site). Mercury is the one at the bottom right.
answered 11 hours ago
L.Dutch♦
62.2k18144291
No
Reflecting and focusing light requires a strict control on the geometry of the system.
What you need to deflect light hitting Mercury and focus it on Neptune is an adaptive parabolic mirror with adjustable focal length in a working range of millions of kilometers.
Even if that was possible, you would still have two major problems to overcome:
- The Sun covering Mercury as seen from Neptune for roughly half of the time
- Mercury being flimsy in comparison to Neptune (see image, courtesy of this site). Mercury is the one at the bottom right.
answered 11 hours ago
L.Dutch♦
62.2k18144291
answered 11 hours ago
L.Dutch♦
62.2k18144291
answered 11 hours ago
L.Dutch♦
62.2k18144291
answered 11 hours ago
L.Dutch♦
62.2k18144291
62.2k18144291
add a comment |Â
add a comment |Â
up vote
2
down vote
Kind of related to your question - there have been several proposals in the past for the use of giant space mirrors. The idea however, was to cool down the planet by blocking a portion of the incoming sunlight. One was proposed as a way to combat global warming, and the idea was also proposed to start terraforming Venus.
There was also a project called Znamya which was a Russian project using a space-based mirror. A prototype was successfully deployed - the idea was to help boost solar production on the ground by increasing the sunlight.
If you wanted to warm up a planet or moon in the outer solar system, a better approach might be to park giant mirrors close to the target, to catch and concentrate more of the weak solar energy. That way you don't have to worry about further diffusion and aiming.
However, a giant parabolic or slightly curved mirror might be able to focus a beam of sunlight and send it into the outer solar system without dispersing. You'd have to keep re-orientating the mirror to aim it though, as you're trying to hit a moving target.
answered 11 hours ago
Chromane
1,889320
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
add a comment |Â
up vote
2
down vote
Kind of related to your question - there have been several proposals in the past for the use of giant space mirrors. The idea however, was to cool down the planet by blocking a portion of the incoming sunlight. One was proposed as a way to combat global warming, and the idea was also proposed to start terraforming Venus.
There was also a project called Znamya which was a Russian project using a space-based mirror. A prototype was successfully deployed - the idea was to help boost solar production on the ground by increasing the sunlight.
If you wanted to warm up a planet or moon in the outer solar system, a better approach might be to park giant mirrors close to the target, to catch and concentrate more of the weak solar energy. That way you don't have to worry about further diffusion and aiming.
However, a giant parabolic or slightly curved mirror might be able to focus a beam of sunlight and send it into the outer solar system without dispersing. You'd have to keep re-orientating the mirror to aim it though, as you're trying to hit a moving target.
answered 11 hours ago
Chromane
1,889320
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
add a comment |Â
up vote
2
down vote
up vote
2
down vote
Kind of related to your question - there have been several proposals in the past for the use of giant space mirrors. The idea however, was to cool down the planet by blocking a portion of the incoming sunlight. One was proposed as a way to combat global warming, and the idea was also proposed to start terraforming Venus.
There was also a project called Znamya which was a Russian project using a space-based mirror. A prototype was successfully deployed - the idea was to help boost solar production on the ground by increasing the sunlight.
If you wanted to warm up a planet or moon in the outer solar system, a better approach might be to park giant mirrors close to the target, to catch and concentrate more of the weak solar energy. That way you don't have to worry about further diffusion and aiming.
However, a giant parabolic or slightly curved mirror might be able to focus a beam of sunlight and send it into the outer solar system without dispersing. You'd have to keep re-orientating the mirror to aim it though, as you're trying to hit a moving target.
answered 11 hours ago
Chromane
1,889320
Kind of related to your question - there have been several proposals in the past for the use of giant space mirrors. The idea however, was to cool down the planet by blocking a portion of the incoming sunlight. One was proposed as a way to combat global warming, and the idea was also proposed to start terraforming Venus.
There was also a project called Znamya which was a Russian project using a space-based mirror. A prototype was successfully deployed - the idea was to help boost solar production on the ground by increasing the sunlight.
If you wanted to warm up a planet or moon in the outer solar system, a better approach might be to park giant mirrors close to the target, to catch and concentrate more of the weak solar energy. That way you don't have to worry about further diffusion and aiming.
However, a giant parabolic or slightly curved mirror might be able to focus a beam of sunlight and send it into the outer solar system without dispersing. You'd have to keep re-orientating the mirror to aim it though, as you're trying to hit a moving target.
answered 11 hours ago
Chromane
1,889320
answered 11 hours ago
Chromane
1,889320
answered 11 hours ago
Chromane
1,889320
answered 11 hours ago
Chromane
1,889320
1,889320
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
add a comment |Â
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
If you think about the sun-planet system, the sun is huge, whereas the planet is small. Therefore it seems logical that building the same-size mirror will get you better results by increasing the effective "catching" size (at the planet) than "throwing" size (at the star) - because it's bigger in proportion to the body.
– Cadence
11 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
Which is why I suggested mirrors closer to the target planet. However the sunlight is now concentrated closer to the sun, so if you could focus and "beam" it, you'd get more sunlight per m^2 of mirror
– Chromane
9 hours ago
add a comment |Â
up vote
1
down vote
No, because the tidal forces are too high.
Because the planet Mercury is so close to the Sun, it experiences enormous tidal forces, about 17 times stronger than the moon's effect on the Earth. Furthermore, the planet's orbit is eccentric, so these tidal forces vary. The forces are so strong that Mercury's spin is 3:2 tidally locked to the Sun (i.e. 3 rotations about the planet's axis for every 2 orbits around the Sun).
Venus and Mars lack a magnetic field because their cores cooled billions of years ago. Mercury ought to be this way, too, but it's not. Mercury's tidal forces are also strong enough to keep the planet's iron core molten and flowing, giving the planet a magnetic field. Think about this: the tidal forces are strong enough to melt iron.
Whether your mirror is built on top of Mercury, built by the material of Mercury, or just in the same orbit of Mercury, it will experience these tidal forces. In the worst case, the tidal forces will tear apart your mirror. In the best case, they will deform the mirror so it no longer produces a collimated beam. The light from your mirror will be no more concentrated than the light directly from the Sun.
answered 11 hours ago
Dr Sheldon
473114
add a comment |Â
up vote
1
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No, because the tidal forces are too high.
Because the planet Mercury is so close to the Sun, it experiences enormous tidal forces, about 17 times stronger than the moon's effect on the Earth. Furthermore, the planet's orbit is eccentric, so these tidal forces vary. The forces are so strong that Mercury's spin is 3:2 tidally locked to the Sun (i.e. 3 rotations about the planet's axis for every 2 orbits around the Sun).
Venus and Mars lack a magnetic field because their cores cooled billions of years ago. Mercury ought to be this way, too, but it's not. Mercury's tidal forces are also strong enough to keep the planet's iron core molten and flowing, giving the planet a magnetic field. Think about this: the tidal forces are strong enough to melt iron.
Whether your mirror is built on top of Mercury, built by the material of Mercury, or just in the same orbit of Mercury, it will experience these tidal forces. In the worst case, the tidal forces will tear apart your mirror. In the best case, they will deform the mirror so it no longer produces a collimated beam. The light from your mirror will be no more concentrated than the light directly from the Sun.
answered 11 hours ago
Dr Sheldon
473114
add a comment |Â
up vote
1
down vote
up vote
1
down vote
No, because the tidal forces are too high.
Because the planet Mercury is so close to the Sun, it experiences enormous tidal forces, about 17 times stronger than the moon's effect on the Earth. Furthermore, the planet's orbit is eccentric, so these tidal forces vary. The forces are so strong that Mercury's spin is 3:2 tidally locked to the Sun (i.e. 3 rotations about the planet's axis for every 2 orbits around the Sun).
Venus and Mars lack a magnetic field because their cores cooled billions of years ago. Mercury ought to be this way, too, but it's not. Mercury's tidal forces are also strong enough to keep the planet's iron core molten and flowing, giving the planet a magnetic field. Think about this: the tidal forces are strong enough to melt iron.
Whether your mirror is built on top of Mercury, built by the material of Mercury, or just in the same orbit of Mercury, it will experience these tidal forces. In the worst case, the tidal forces will tear apart your mirror. In the best case, they will deform the mirror so it no longer produces a collimated beam. The light from your mirror will be no more concentrated than the light directly from the Sun.
answered 11 hours ago
Dr Sheldon
473114
No, because the tidal forces are too high.
Because the planet Mercury is so close to the Sun, it experiences enormous tidal forces, about 17 times stronger than the moon's effect on the Earth. Furthermore, the planet's orbit is eccentric, so these tidal forces vary. The forces are so strong that Mercury's spin is 3:2 tidally locked to the Sun (i.e. 3 rotations about the planet's axis for every 2 orbits around the Sun).
Venus and Mars lack a magnetic field because their cores cooled billions of years ago. Mercury ought to be this way, too, but it's not. Mercury's tidal forces are also strong enough to keep the planet's iron core molten and flowing, giving the planet a magnetic field. Think about this: the tidal forces are strong enough to melt iron.
Whether your mirror is built on top of Mercury, built by the material of Mercury, or just in the same orbit of Mercury, it will experience these tidal forces. In the worst case, the tidal forces will tear apart your mirror. In the best case, they will deform the mirror so it no longer produces a collimated beam. The light from your mirror will be no more concentrated than the light directly from the Sun.
answered 11 hours ago
Dr Sheldon
473114
edited 11 hours ago
answered 11 hours ago
Dr Sheldon
473114
answered 11 hours ago
Dr Sheldon
473114
answered 11 hours ago
Dr Sheldon
473114
473114
add a comment |Â
add a comment |Â
up vote
1
down vote
No, because you cannot gather light
As I wrote in this answer, you cannot actually gather light. You cannot gather light from a wide cone, and then send it out into a thin beam. Whatever the angle was that you collected light from, what you emit cannot be a more narrow angle than that, if you are using only optics (i.e. refraction and reflection).
This is called Conservation of Étendue and xkcd has a better write-up of that than I can produce.
Mercury is at about 0.4 AU from the sun, while Neptune is at 30 AU. 30/0.4 = 75. This means that whatever light you reflect off of Mercury, when it reaches Neptune that light covers an area that is 75 time larger than the Sun, in effect 75 times weaker per unit of surface area than what hits Mercury.
Also The Sun has a surface area that is about 80 000 times as large as that of Mercury, so now we are down by a factor of 6 000 000.
So no... this just is not worth the effort at all.
answered 9 hours ago
MichaelK
34.5k584146
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
 |Â
show 3 more comments
up vote
1
down vote
No, because you cannot gather light
As I wrote in this answer, you cannot actually gather light. You cannot gather light from a wide cone, and then send it out into a thin beam. Whatever the angle was that you collected light from, what you emit cannot be a more narrow angle than that, if you are using only optics (i.e. refraction and reflection).
This is called Conservation of Étendue and xkcd has a better write-up of that than I can produce.
Mercury is at about 0.4 AU from the sun, while Neptune is at 30 AU. 30/0.4 = 75. This means that whatever light you reflect off of Mercury, when it reaches Neptune that light covers an area that is 75 time larger than the Sun, in effect 75 times weaker per unit of surface area than what hits Mercury.
Also The Sun has a surface area that is about 80 000 times as large as that of Mercury, so now we are down by a factor of 6 000 000.
So no... this just is not worth the effort at all.
answered 9 hours ago
MichaelK
34.5k584146
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
 |Â
show 3 more comments
up vote
1
down vote
up vote
1
down vote
No, because you cannot gather light
As I wrote in this answer, you cannot actually gather light. You cannot gather light from a wide cone, and then send it out into a thin beam. Whatever the angle was that you collected light from, what you emit cannot be a more narrow angle than that, if you are using only optics (i.e. refraction and reflection).
This is called Conservation of Étendue and xkcd has a better write-up of that than I can produce.
Mercury is at about 0.4 AU from the sun, while Neptune is at 30 AU. 30/0.4 = 75. This means that whatever light you reflect off of Mercury, when it reaches Neptune that light covers an area that is 75 time larger than the Sun, in effect 75 times weaker per unit of surface area than what hits Mercury.
Also The Sun has a surface area that is about 80 000 times as large as that of Mercury, so now we are down by a factor of 6 000 000.
So no... this just is not worth the effort at all.
answered 9 hours ago
MichaelK
34.5k584146
No, because you cannot gather light
As I wrote in this answer, you cannot actually gather light. You cannot gather light from a wide cone, and then send it out into a thin beam. Whatever the angle was that you collected light from, what you emit cannot be a more narrow angle than that, if you are using only optics (i.e. refraction and reflection).
This is called Conservation of Étendue and xkcd has a better write-up of that than I can produce.
Mercury is at about 0.4 AU from the sun, while Neptune is at 30 AU. 30/0.4 = 75. This means that whatever light you reflect off of Mercury, when it reaches Neptune that light covers an area that is 75 time larger than the Sun, in effect 75 times weaker per unit of surface area than what hits Mercury.
Also The Sun has a surface area that is about 80 000 times as large as that of Mercury, so now we are down by a factor of 6 000 000.
So no... this just is not worth the effort at all.
answered 9 hours ago
MichaelK
34.5k584146
edited 5 hours ago
answered 9 hours ago
MichaelK
34.5k584146
answered 9 hours ago
MichaelK
34.5k584146
answered 9 hours ago
MichaelK
34.5k584146
34.5k584146
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
 |Â
show 3 more comments
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
I've found solar constants for Mercury and Neptune to be 9200 W/m^2 and 1.5 W/m^2 respectively. Using your calculation, this setup would still about double the solar radiation on Neptune.
– Jens
6 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
@Jens I must have made a mistake in calculation then because that does not make sense at all. EDIT: Yeah, I just realised, it is not the Mercury / Neptune ratio I want, but the Mercury / Sol ratio.
– MichaelK
5 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
While I agree with your conclusion, I think your first paragraph is misleading at best. I know everyone loves XCKD here (myself included) but let's not forget he is writing for the masses and humor, while keeping things as science-based as possible. This means handwavium in his answers (or maybe just honest mistakes). There are differences between reflection off of the moon, mirrors, and black-body radiation. There are differences between imaginary point sources and actual objects with dimensions like the sun. <cont>
– ColonelPanic
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
@ColonelPanic Actually, if Sol had been point source, then the scheme could have worked. But it is not a point source... it is spread out. And then you can just forget about this scheme immediately because with reflection alone you cannot do it.
– MichaelK
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
The best case for what we could focus on neptune using an object the size of Mars through free-space would be conveying nearly the entirety of the energy incident on this body from the sun. Call it 590W/m2 on a body with diameter 6800km. Agreed that this wouldn't be much to Neptune, but it would provide energy.
– ColonelPanic
4 hours ago
 |Â
show 3 more comments
up vote
0
down vote
As everyone else said, there is no scientifically solid way to effectively reflect a sufficient amount of light from Mercury to Saturn.
But you're in luck since Russian scientists already found a solution to your problem: Project Znamya (meaning "Banner) they constructed a 65-foot-wide sheet of mylar that could be unfurled from a central mechanism and launched from the Mir space station.
They basically sent a giant mirror in orbit around Earth, in your case it would be orbiting around Saturn or its satellites.
The experiment did in fact work but to have a system that could actually be used to lit up the whole planet they still had a long way ahead
First of all the size of the mirror
The plan was to first test a 65-foot mirror (Znamya 2), then a 82-foot
version (Znamya 2.5), finalize the test phase with a 230-foot mirror
(Znamya 3), and, eventually launch a permanent 656-foot space mirror
installation that would be capable of fully turning early night in
Russian cities into something close to full-blown day.
And then the scale of the system
"The scheme called for a chain of many satellites to be placed in
sun-synchronized orbits at an altitude of 1700 kilometers, each one
equipped with fold-out parabolic reflectors of paper-thin material,"
Crary writes. "Once fully extended to 200 meters in diameter, each
mirror satellite would have the capacity to illuminate a
ten-square-mile area on earth with a brightness nearly 100 times
greater than moonlight."
And we're talking about Earth. Saturn has diameter 9.5 times bigger than our planet and a surface 83 times bigger. So of course your satellites will need to be way more that what you'd use to lit up Earth and probably bigger as well.
For a more in depth article: The Man Who Turned Night Into Day
answered 6 hours ago
Bolza
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
0
down vote
As everyone else said, there is no scientifically solid way to effectively reflect a sufficient amount of light from Mercury to Saturn.
But you're in luck since Russian scientists already found a solution to your problem: Project Znamya (meaning "Banner) they constructed a 65-foot-wide sheet of mylar that could be unfurled from a central mechanism and launched from the Mir space station.
They basically sent a giant mirror in orbit around Earth, in your case it would be orbiting around Saturn or its satellites.
The experiment did in fact work but to have a system that could actually be used to lit up the whole planet they still had a long way ahead
First of all the size of the mirror
The plan was to first test a 65-foot mirror (Znamya 2), then a 82-foot
version (Znamya 2.5), finalize the test phase with a 230-foot mirror
(Znamya 3), and, eventually launch a permanent 656-foot space mirror
installation that would be capable of fully turning early night in
Russian cities into something close to full-blown day.
And then the scale of the system
"The scheme called for a chain of many satellites to be placed in
sun-synchronized orbits at an altitude of 1700 kilometers, each one
equipped with fold-out parabolic reflectors of paper-thin material,"
Crary writes. "Once fully extended to 200 meters in diameter, each
mirror satellite would have the capacity to illuminate a
ten-square-mile area on earth with a brightness nearly 100 times
greater than moonlight."
And we're talking about Earth. Saturn has diameter 9.5 times bigger than our planet and a surface 83 times bigger. So of course your satellites will need to be way more that what you'd use to lit up Earth and probably bigger as well.
For a more in depth article: The Man Who Turned Night Into Day
answered 6 hours ago
Bolza
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
0
down vote
up vote
0
down vote
As everyone else said, there is no scientifically solid way to effectively reflect a sufficient amount of light from Mercury to Saturn.
But you're in luck since Russian scientists already found a solution to your problem: Project Znamya (meaning "Banner) they constructed a 65-foot-wide sheet of mylar that could be unfurled from a central mechanism and launched from the Mir space station.
They basically sent a giant mirror in orbit around Earth, in your case it would be orbiting around Saturn or its satellites.
The experiment did in fact work but to have a system that could actually be used to lit up the whole planet they still had a long way ahead
First of all the size of the mirror
The plan was to first test a 65-foot mirror (Znamya 2), then a 82-foot
version (Znamya 2.5), finalize the test phase with a 230-foot mirror
(Znamya 3), and, eventually launch a permanent 656-foot space mirror
installation that would be capable of fully turning early night in
Russian cities into something close to full-blown day.
And then the scale of the system
"The scheme called for a chain of many satellites to be placed in
sun-synchronized orbits at an altitude of 1700 kilometers, each one
equipped with fold-out parabolic reflectors of paper-thin material,"
Crary writes. "Once fully extended to 200 meters in diameter, each
mirror satellite would have the capacity to illuminate a
ten-square-mile area on earth with a brightness nearly 100 times
greater than moonlight."
And we're talking about Earth. Saturn has diameter 9.5 times bigger than our planet and a surface 83 times bigger. So of course your satellites will need to be way more that what you'd use to lit up Earth and probably bigger as well.
For a more in depth article: The Man Who Turned Night Into Day
answered 6 hours ago
Bolza
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
As everyone else said, there is no scientifically solid way to effectively reflect a sufficient amount of light from Mercury to Saturn.
But you're in luck since Russian scientists already found a solution to your problem: Project Znamya (meaning "Banner) they constructed a 65-foot-wide sheet of mylar that could be unfurled from a central mechanism and launched from the Mir space station.
They basically sent a giant mirror in orbit around Earth, in your case it would be orbiting around Saturn or its satellites.
The experiment did in fact work but to have a system that could actually be used to lit up the whole planet they still had a long way ahead
First of all the size of the mirror
The plan was to first test a 65-foot mirror (Znamya 2), then a 82-foot
version (Znamya 2.5), finalize the test phase with a 230-foot mirror
(Znamya 3), and, eventually launch a permanent 656-foot space mirror
installation that would be capable of fully turning early night in
Russian cities into something close to full-blown day.
And then the scale of the system
"The scheme called for a chain of many satellites to be placed in
sun-synchronized orbits at an altitude of 1700 kilometers, each one
equipped with fold-out parabolic reflectors of paper-thin material,"
Crary writes. "Once fully extended to 200 meters in diameter, each
mirror satellite would have the capacity to illuminate a
ten-square-mile area on earth with a brightness nearly 100 times
greater than moonlight."
And we're talking about Earth. Saturn has diameter 9.5 times bigger than our planet and a surface 83 times bigger. So of course your satellites will need to be way more that what you'd use to lit up Earth and probably bigger as well.
For a more in depth article: The Man Who Turned Night Into Day
answered 6 hours ago
Bolza
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 6 hours ago
answered 6 hours ago
Bolza
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 6 hours ago
Bolza
1395
answered 6 hours ago
Bolza
1395
1395
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Bolza is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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add a comment |Â
Shane Mulligan is a new contributor. Be nice, and check out our Code of Conduct.
Shane Mulligan is a new contributor. Be nice, and check out our Code of Conduct.
Shane Mulligan is a new contributor. Be nice, and check out our Code of Conduct.
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"mercury" the element, or Mercury the planet?
– RonJohn
12 hours ago
5
If you mean Mercury the planet, note that it is veeeerrrryyyy small, moving veeeerrrryyyy fast, and Neptune is veeeerrrryyyy far away.
– RonJohn
12 hours ago
I am not sure the tag you selected is the most appropriate. Please reconsider it (read its description) and also considering adding some other
– L.Dutch♦
7 hours ago
It is not like Neptune's habitability is mainly limited by its temperature, so even if possible, this would probably be of limited use.
– Jens
6 hours ago