The absence of sun is the reason for night.So is it possible for a huge satellite to reflect the light coming from the sun to lighten up the darker side of Earth (the side enjoying the night) ?


Actually i asked this question because to know about the possibility.

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    $\begingroup$ It's called the moon.... $\endgroup$ – Tim B Feb 5 '15 at 15:00
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    $\begingroup$ It is possible. Question is: are the benefits worth the expenses. $\endgroup$ – Peter M. - stands for Monica Feb 5 '15 at 15:00
  • $\begingroup$ For the Earth, this would be possible but (as everyone is pointing out) pointless and destructive. If you wanted to terraform Mars, a giant solar reflector would actually be quite useful -- although you would probably point it at the day side in order to keep a sensible day/night cycle. $\endgroup$ – Royal Canadian Bandit Feb 5 '15 at 15:08
  • $\begingroup$ Are you asking about the mechanics necessary to make the "dark side" of Earth as bright as day? If so, that is a good question; however, as your question stands, it is entirely possible and, as pointed out already, is done today with artificial and natural satellites. $\endgroup$ – Mikey Aug 4 '15 at 19:50

Not only is it possible, it's been done. Over 20 years ago:


Unfurling a thin aluminum and plastic mirror in space, Russian scientists and engineers for the first time have sent a narrow beam of reflected sunlight flashing across the darkened side of the Earth.


Yes, but would also be a terrible idea. One very quick and easy way to imagine is this way: The Sun shines on half the planet, with half the planet in sunlight, everything we know grows. Now imagine if the Sun shines on the entire planet, now the planet has roughly twice the sunlight. As well twice the light and heat energy, twice the UV radiation and possibly twice the solar flares.

The entire world would then quite easily turn into a water world, with the polar ice caps melting and the usual host of problems that brings about. On the other hand, this seems like a delightfully evil masterplan of some evil genius, disguised under the best intentions

EDIT: Changing questions, changing answers

As for the possibility of reflecting the light from the Sun with a single satellite, the physics checks out, you could assemble a gigantic, at least moon-sized space station, although it would need to be launched piece by piece and assembled in space. Performing the feat would be much much simpler, cheaper and easier with many small satellites instead.

  • $\begingroup$ I just wanted to know whether it is possible . $\endgroup$ – CodeIt Feb 5 '15 at 15:08
  • $\begingroup$ @manutd alrighty then, I have edited my answer accordingly, and it is posssible $\endgroup$ – grimmsdottir Feb 5 '15 at 15:30

It is possible. With no budget limits, lots of things are possible. Question is: are the benefits worth the expenses.

You can build bunch of satellites - reflecting sheet, hold spread by rotation. Spend fuel to orient them in space properly. More fuel to repair micrometeorite damage.

What would be the benefit? Also, astronomy from Earth would be impossible with all that light, and there would be huge consequences for animal and plant world - there are all kinds of adaptation to night which will be useless and whole ecosystem would be disrupted. Lots of people might objects to such changes.

So what are the expected benefits, worth such huge disruption?

  • $\begingroup$ I just wanted to know whether it is possible . $\endgroup$ – CodeIt Feb 5 '15 at 15:07

Can be controlled, just like the LED light which would not emit heat.This is actually a good idea as those urbanized cities who can afford the expense will have an extended work hours and productivity.

  • $\begingroup$ Welcome (again!) to the site, Gerentstein. While I recognize that the question itself (which is over a year old) omits a few important details, can you elaborate on your answer at all? For example: more details on how your reflected light source might be designed, and how (as you mention) it might be controlled. $\endgroup$ – type_outcast Mar 31 '16 at 3:42
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    $\begingroup$ Thank you type_outcast, what I mean is that white lights won't melt ice caps, neither would it obstruct plant growth. LED lights do not emit warm/heat. Moonlight is the same with LED lights, it illuminates but won't emit heat. If we have to design, of course with much cost, a satellite which mimics the moon's light pointing to some portions of the dark side of the earth, we can increase productivity, reducing fuel, coal, nuclear, etc., consumption. With this, we can even prevent climate change by reducing heat emissions. $\endgroup$ – gerentstein banzon Mar 31 '16 at 8:35

protected by L.Dutch - Reinstate Monica Aug 27 at 9:44

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