Why the sky appears orange yellow at sunset sunrise?

Answer 1

Orange in the sky at night is caused by lights from urban areas. Simply put, it is light pollution.

An orange glow in the mornings or evenings is caused by smoke and dust on the lower horizon. The forest fires in California can cause a red sunset in New York City.

Answer 2

Sunlight contains all the colors of the rainbow. Particles floating in the air scatter some of the light (usually blue/violet) which is why the sky looks blue. During the early morning (and early evening) the light has to pass through more atmosphere to reach your eyes. The blue/violet has already been scattered away. The longer wavelengths (red and orange) are the ones that get through so that is why the sky is orange during sunrise.

Answer 3

This is because when you see the Sun near to the surface of the Earth, then the light will have to pass through a lot of atmosphere, as the Sun rises higher and higher, the light falls directly to the earth.

Darker shades of the sunset and sunrise , are due in large part to atmospheric pollution , dust etc..

Basically, sunsets are red and orange because the sky is blue.

Your next question might then be: why is the sky blue?

This is because the sky - the atmosphere - is a vapor (gas) made up of vast amounts of molecules (mostly nitrogen and oxygen molecules) that react differently to light of different wavelengths. The sun emits enormous amounts of electromagnetic radiation, including the small part of the ER-spectrum that we call visible light. It is therefore white in appearance.

However, the high-frequency (and thus small wavelength) photons (the blue end of the spectrum) are affected more by their interactions with the atmosphere than the low-frequency, large wavelength radiation (the red/orange part of the spectrum). These interactions cause the blue light to scatter in random directions from the points of impact between light and gas molecule - and since these impacts occur throughout the atmosphere, Earth's gaseous shell essentially becomes a bulk emitter (technically a reflector/refractor) of blue light!

This is why the sky is blue when you look up, and this is why objects in the far distance (such as mountains) are blueish and hazy: there is now a lot of blue-light-scattering-gas between you and the object you're looking at (say, a mountain).

So that the light reaching you from the mountains consists of both the photons they reflected in our direction PLUS the photons that were scattered in our direction from anywhere between our eyes and the mountains, and the ratio of "actual object light/scattered light" decreases with increasing distance (so, if we look far enough away or up, we will see only blue sky).

What happens at night then?

At night, the only light significant light reaching us from space comes from the moon; it, however, is a much dimmer light source, and no significant amount of scattered light enters our eyes. The sun literally "lights up the sky" with its abundance of radiation, which also explains why there isn't complete darkness in shadows on a sunny day (but there IS complete darkness in a cavern shield from the atmospheric light scatterer at all times).

So many different colors and shades!

It is also the reason why the sun looks yellow when it is high in the sky: some of the blue light it sends our way gets scattered in different direction, but the yellow/red wavelengths reach us unhindered. When the sun is low on the horizon, its light rays pass through a larger volume of atmospheric gas before they reach us, and so more of the blue is filtered out - until you are left with mostly low frequency light, which is red/orange in appearance.

Normally, the Sun has a slightly yellow tint because the blue end of the spectrum is scattered out a little bit, which is mostly offset by the fact that the rest of the sky is blue (so any object on the ground still receives both ends of the spectrum).

Catch it at dawns and sunsets to get the most of colors!

When the sun is setting (or rising) its rays have to pass through a thick layer of atmosphere to get to the observer. Light of lower frequencies (red and infrared) is less likely to be blocked by the atmosphere than the high-frequency blue light. Thus, most of the blue rays are absorbed by the atmosphere on the way to the observer, while some of the red rays are not. The observer only sees the red rays, which makes the sun appear red.

Answer 4

When the sun sets the sky turns orange.

Answer 5

because the sun is going down