Why is the outer space always dark..even though sunlight passes through it and only then reaches the Earth?

Question

In all the space photos I've seen,space has always been dark...so i would like to know why it is so,even though sunlight passes through it and only then reaches the Earth....

Answer 1

Light particles need to be bent in order to see them, in space it is just a vacuum, there is nothing there to bend the light. The reason you see the stars and planets is because they reflect or bend the light.

Answer 2

Think of light as being like a stream of small particles the size of a piece of rice. Now we build a detector that "sees" them when they enter through the front. The detector is like the eye which only "sees" light that enters through the pupil.

Now we put our detector up in space. The space is packed with these little particles zooming by. They leave the sun and move outwards. But, our detector "eye" is not pointed at the sun at the moment, so none of them enter it and are detected. So even though the detector "eye" is surrounded by these little particles, it can't "see" any of them.

Of course, if we hold up a 4x8 sheet of plywood (NASA is footing the bill here, so we can put up anything we want), the little rice-sized particles will hit the surface and be reflected off into all directions. If our detector eye is pointed at (looking at) the board, it will now see light coming from that direction.

In the same way, if we were in space, even though we are surrounded by light, we would not see it unless we turned and looked at the sun, the piece of plywood, or something else reflecting light (like the earth or moon).

Now if we float a marbles around our original detector, they will scatter the rice-sized particles all around. Then no matter which way our detector eye looks, it will see the light bouncing back. The light has been scattered all around.

The earth's atmosphere works in this way. Of all of the visible colors, blue is the easiest to scatter, so the atmosphere scatters the blue light all around so it is coming at our eyes from all directions of the sky. So the sky looks blue.

However as we saw, up in space it is not being scattered so again, even though our detector is surrounded by rice-sized light particles, our detector won't see them because they don't enter the front of the detector.

If you are interested in astronomy, try
http://groups.yahoo.com/group/lunar-observing/
You will find a large number of amateur astronomers who are glad to answer questions and talk about what they are observing. We also have an outstanding group of photographers who enjoy helping others take pictures of the moon.

Chuck

Answer 3

Outer Space is always dark because, possibly, light is not being reflected. So it is becase there are no object or particles that reflect it. So you don't see it. You see it on Earth.

Answer 4

Humans can only see an object if:
1) it emits light; or
2) it reflects light
AND
3) the photons reach our optical receptors.

There is not enough mass in space to reflect light.

Lack of light is dark.

Answer 5

In space there is nothing to reflect light to you, except for planets, comets... So space is dark and objects flying in space depends on how much light they reflect.

Answer 6

In space there is nothing to reflect sunlight, so it appears dark.

Answer 7

Space is a vacuum. Nothing to reflect light!

Answer 8

Light is the result of photons being absorbed by atoms and emitted again by those atoms at a certain frequency. If thaf frequency is in the visible spectrum of light, we see color. No atoms, no color. Once this liight (photons) strike the atoms in our atmosphere, most of the photons reemitted by the atoms that absorbed them have a frequency in the visible spectrum that the cones in our eyes interpret as "blue."

Answer 9

There is nothin in space that can bend the light.

Answer 10

"light" is not something that you can see .. photons travel invisibly through space and stuff shows up when they bounce off it. You never "see" light .. light lets you see stuff when it hits the stuff.