What color is the sun when it rises?

On earth, it is red, orange red, orange yellow and yellow. In fact, it is because the atmosphere and air block the sunlight. There is a lot of floating dust in the air in the morning, and the red light has a long wavelength and strong penetration. In fact, the color of sunlight is constant.

When solar radiation is not blocked by clouds, it is usually called sunshine when it is directly illuminated, which is a combination of bright light and radiant heat. The definition of "sunshine time" by the World Meteorological Organization is that an area receives more than 0/20 watts of direct sunlight per square meter/kloc.

The time of sunlight exposure can be recorded by camera, all-sky radiometer or heliometer. It takes 8.3 minutes for sunlight to reach the earth from the sun.

The brightness efficiency of direct sunlight is about 93 lumens per watt, including infrared, visible and ultraviolet rays. Bright sunlight provides illumination on the earth's surface of about per square meter 100000 lumens or 100000 lux. Sunlight is the key factor of photosynthesis and is very important to life on earth.

Extended data:

The sunlight on Mars will be more or less like the sunlight wearing sunglasses on the earth, and it can be seen from the pictures sent back by the rover that there is enough diffuse reflection in the sky, so the shadow area will not be excessively dark. So it gives us the feeling and view that it is very similar to the daytime of the earth.

For comparison purposes, the sunlight on Saturn is brighter than the sunlight at sunrise or sunset on Earth (see the sunlight comparison table). Even on Pluto, the sunlight is still bright enough, almost equal to the average brightness of the living room. At a distance of 500 astronomical units (~ 69 light), sunlight will dim to about the brightness under the full moon of the earth. ?