I wasn't sure this belongs here , but since it's called : Mind space and time , i thought it's Ok .

Now , I have always wondered why our moon reflects the sun light , thus bringing light in the evening and night to Earth .
But since our moon is a solid planet , made of rocks , stones , dust ..etc .. how come it is reflective and Earth isn't ? Let alone the fact that Earth is made 70% of water .. which ought to be HIGHLY reflective .. like a mirror .
So , does Earth also reflect the sun shine to some other place ? I don't think i ever read that .
But why the moon ... and not the Earth .. actually , considering Earth's size .. it would make more sense if Earth sent some reflected light to the tiny moon ??!!

I don't get it !

Sama

The Earth does reflect light. What makes you think it does not?

Ya ? Whereto ? You mean , we actually "are" also a moon ?
I had no idea .

Sama

I see i had placed this in the wrong place . Sorry ! and thanks for having moved it .

We reflect it out into space...just like the moon does. Technically we are a planet, not a moon, but we absorb some of the light and energy that comes from the sun, and reflect lots of it back into space.

This picture:


Is a pic of the earth from the planet mars. The light of the sun is being reflected off the earth and that is how we can see the crescent of the earth in the photo.

This is awesome . Thanks Fluffybunny . Amazing picture . Sorry i didn't know that !

There is no need to apologize, that is what forums are for. We are all here to learn. I wish that one of the Astronomer geek types were here to explain it better...Where is Waspie

One thing that came to mind... Mercury, Venus, Mars, Jupiter, and Saturn are all planets (Jupiter and Saturn are made of a lot of dense gas primarily though), but they too reflect light and can be seen with the naked eye if you know where to look at in the nights sky. They are reflecting the same sunlight that the earth and the moon does...

The picture below shows how big the planets and the sun are compared to each other...not how close they are though!

Waow .. this makes sense ! Thanks again.
How about the stars ? I mean , those in our galaxy .. are they also reflecting the sun ? I know , that what we see is the light of a long gone star .. so what is that light ?

Sama

Well, the stars are, uh, stars. They create their own light.

Ya , sure , i know that . But just in case i missed something ( like i only learned tonight that Earth { and evrey other planet }are reflecting light ) ... is it correct that stars produce their own light ( thru explosion etc ) ... noway any star is reflecting our sun ( or any other sun ?

I'm no astronomer, but isn't light bent by magnetic fields? So when light from our Sun reaches another star, the intense magnetic field that surrounds it will bend light in another direction?

well , if this is true , considering multiplicity and reflection .. there must be only one source of light .. reflected to infinite proportions ?

I don't know if i make sense . But i think it makes sense to me !

Sama

No, stars are like our Sun, they generate their own light and heat. They appear so dim and small because they are so far away.

Light travels at 186,000 miles per second, the Sun is 93 million miles away and so light (and heat) takes about 8 minutes to arrive at the Earth. The closest star to us other than the Sun is Proxima Centauri. Even at light's amazing speed it takes more than 4 years to arrive here. The distance light travels in 1 year is known as a light year and is 5,865,696,000,000 miles (9,460,800,000,000 kilometres). This means Proxima Centauri is 4 light years away. Some of the stars we can see are hundreds or even thousands of light years away. The nearest large galaxy to us is the Andromeda Galaxy, that is 2.2 million light years away and it can be seen with the naked eye. Light left the Andromeda Galaxy before there were even any human beings.

To return to your original question, as Fluffy has said all planets and satellites (and asteroids and comets too) in the solar system reflect the light from the Sun. The average amount of light they reflect is known to astronomers as albedo. The moon is made of relatively dark material and reflects only about 12% of the light that falls on it. For the Earth this is nearer 40%. As the Earth is also considerably larger than the Moon a full Earth seen from the Moon would be much brighter than we see a full moon from Earth.

You said you had never heard of the Earth reflecting light... well it is actually possible to see light reflected by the Earth.

Go and take a look at the Moon when it is a thin crescent. Let your yes adapt for a while and look carefully. You will be able to see not just the crescent but the dark part of the Moon as well. This will be much dimmer than the crescent but it is still visible. What you are seeing is a part of the Moon bathed in "Earthshine". On the crescent part of the Moon it is still day, the sun is above the horizon. On the dark part it is night. The reason that you can see this dark part is because of light being reflected on to the Moon from the Earth and then being reflected back again.

The light that we see of other stars in the night sky are being produced by a nuclear reaction in the center of those stars just like our star does. The light that we see from our sun takes about 8 minutes to get to us if I remember correctly...in other words; lets say tomorrow at exactly noon I turned the sun off, it wouldnt go dark until 12:08... Well our sun is really close by, 93 million miles, or in light speed, 8 light minutes.... The next closest star is Alpha Proxima Which is I believe about 4.5 light YEARS away. So if it got turned out tomorrow at noon you wouldnt know until noon....of May 17 2012(I dont know the exact number, but 4 and a half years from now give or take).

Keep in mind that is our NEAREST neighbor. We are a long way from anything....


The star (our sun) at the center of our solar system(Our group of planets) is made up of mainly hydrogen, but it is really big and because it is so big it creates a lot of pressure in the middle of the sun(Think of diving to the bottom of a deep pool-it makes your ears pop because of the increase in pressure, now make that billions of times harder), the pressure gets so high that it can squish hydrogen atoms together and make helium out of it, and in the process make heat and light, which is what we see and feel when we go outside on a warm day.

It gets a lot more technical than that, but beyond that you would have to ask a science geek. I am sure those geeks are reading this and rolling their eyes now but I am doing my best...

There are lots of different sizes of stars, some are smaller, some that make our star look like a little wimpy tiny star even...sometimes those stars have burned up all of the fuel they had; they went dark like a candle going out, sometimes when they run out of fuel, they blow up and scatter matter all over the place.

Thanks a lot waspie . I actually have seen the moon ( on crescent nights ) the way you describe it.. thought i saw the whole moon in the dark , sort of surrounded by a tiny light circle .. now i know that i saw Earth's reflection .
Now to "albedo " .. do we get some of that , too ? Meaning is our moon ( being the nearest i suppose ) - together with the sun and stars - the only sources of light ?

I know gravity bends light...

Waspie? Help?

this pic is a great shot of 'earthrise' from the moon landings, shows the earth reflecting sunlight to the surface of the moon

as far as stars reflecting light, they may reflect some, but it would be the same as a lit lightbulb reflecting light, you wouldn't notice any reflected light because it would be drowed out by the light being produced

Actually not only planets, but all objects or most of them in existence reflect light and that's how you see them, see the light impacts the objects, they absorb some of it and they reflect the other part into the atmosphere or space. You can somehow say they bounce of these objects. See that's how a mirror works, a mirror is just a random piece of glass wich was provided with an opaque object objects on one of it's side ( an opaque object is an object wich doesn't let light pass through it), this opaque object behind the mirror doesn't let light pass through but reflects it back to the atmosphere or space and so it reaches your eyes and you see it. Just look for any mirror, look at it's back side, you'll see a non-crystal covering, take it off and you have no more mirror but a random piece of glass.




In this diagram plane waves reflect off a parabolic mirror to form waves converging onto a focal point.

Not all smooth surfaces reflect light back to us, even though, technically, they should bounce back at the same angle at which they hit the surface. This exception to the rule results, because some smooth surfaces absorb the light particles hitting them, making it impossible for them to bounce back. The Earth itself does not act like a mirror because it absorbs some of the light it receives from the sun and reflects the other part of it back to space and in not in the same angle it received the light but in diferent angles, the moon does the same thing and almost every object in the universe.



Above pic showing Earth seen from the moon, this is called "Earth rise".

Of course there is an exeption, there are objects that produce light by themselfs and so they make themselves visible that way, one example is the sun, the sun produces its own light, the sun is a light source itself, the light it produces it releases it into space and when it arrives at Earth it arrives at our eyes and so we see the sun and everything it lits with it's light. The sun is one light source in our solar system. Ever wonder why we can't see in the dark? Because there is not light to bounce of the objects so we can see them of there is not light source.

There are many other light sources in the universe, for example other stars. Our sun is a star, but it is not alone in the universe, there are many other stars in the universe and of course they are all a light source each. Of course this other stars are very distant and that's why they appear so small but some of them can be thousands of suns. Fire itself is a light source, it doesn't need to reflect light to be visible because it produces it itself.





I hope this post cleared somethings out.

Source images

That is a bit deceptive as it gives the impression that the lit part of the Moon in that image is illuminated by the Earth, it isn't, it is illuminated by the Sun.

Fluffy is quite right, magnetic fields do not bend light but mass does. Einstein's 1915 Theory of General Relativity predicted that very massive objects bend the three dimensions of space (in much the same way that a heavy object placed on a rubber sheet bends that in two dimensions). This warping of space-time causes light to bend. This prediction was shown to be correct in 1919. Astronomers photographed the positions of stars during a total solar eclipse. Those appearing close to the Sun had moved from their previously measured positions. The mass of the Sun had caused the light from these stars to bend.

Electromagnetic radiation, such as visible light, x-rays, gamma rays, infra-red and ultra-violet will be totally unaffected by magnetic fields. What magnetic fields do affect is radiation which consists of charged particles, such as alpha and beta radiation. The Earth's magnetic field traps these particles in zones known as the Van Allen Belts. Where the magnetic field reaches low enough to touch the atmosphere (at the North and South poles) these particles can interact with the upper atmosphere. This can be seen as the Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights).

interesting topic, if you ever have seen one of those earth and planet toys, the one with a light in the center (the sun) and nine planets around it. you turn the light on and light will shine on all the planets. if they reflect light all depends on the surface. even if their surface doesn't allow as much light to reflect (clouds tend to allow less light to be reflected back) some of that light will be reflected. the moon appears to reflect a lot of light, i wonder if it had a dark soil if it would be as bright, i guess it must have been but became bleached from the sun.