Lunar eclipse: How the Earth turns the 'micro & # 39; red moon with its shadow

Enormous parts of the Earth are in the limelight for a special astronomical treatment at the end of July: the longest total lunar eclipse over a hundred or so years.

On the evening of July 27 and early morning of July 28, Earth will pass between the sun and the moon to cast a shadow over our 4.5 billion-year-old satellite.

The shadow of the Earth is not a dull gray, however.

This goes from orange to a strange red blood hue if you are right in the middle, which is precisely where the moon will be this time.

Here is what works.

How a total lunar eclipse colors the moon in red

A total lunar eclipse and a total solar eclipse are similar, if not the opposite of one another, but their appearances are significantly different.

During a solar eclipse, the moon passes between the Earth and the sun to cast its shadow on our planet. The shade is colorless because the moon has no atmosphere to disperse or refract any sunbeam.

The Earth, of course, is a different story.

The nitrogen-rich atmosphere of our planet takes on a white light, a mixture of all colors of the spectrum, and scatters around the blue colors. This makes the blue sky during the day and the sun yellow.

Around sunset and sunrise, the light that reaches our eyes is more scattered, so that the blues are almost absent. This makes the sun and its light more orange or even red.

About 240,000 kilometers further on the Moon, the Earth would look quite breathtaking because the same air, like a large lens, refracts this tinted light toward the full moon. "If you were standing on the surface of the moon during a lunar eclipse, you would see the sun set and rise behind the Earth," wrote David Diner, a global scientist at NASA's Jet Propulsion Laboratory. "You would observe the sun's rays refracted and scattered as they pass through the atmosphere surrounding our planet."

This is the reason why lunar eclipses are orange-red: all this colored light is focused on the moon in a cone-shaped shadow called the "moon". shadow.

The moon is also covered with an ultra-fine, glass-like rock dust called regolith, which has a special property called "backscatter." This returns a lot of light in the same way it came, in this case to the Earth (Backscattering also explains why the full moons are much brighter than during another lunar phase.)

So when we look at the moon during a total lunar eclipse, we see sunlight and the refracted sunrise of the Earth bouncing off us.

The red color is never quite the same from one lunar eclipse to the other because of the natural and human activities that affect the planet. 39 atmosphere of the Earth.

"Pollution and dust in the lower atmosphere tend to tame the color of the rising or falling sun, while fine smoke particles or tiny aerosols coiled at high altitude during a major volcanic eruption can intensify the color up to 39 to an intense red hue. "Diner said.

This total lunar eclipse will also occur during what is called a "micro" moon, or the opposite of a super moon. This occurs because the moon 's orbit is not perfectly circular, so it seems larger at times and smaller at others during its orbit of about 29 days around. of the earth. (In this case, it will look a little smaller.)

Where and when to see the total lunar eclipse

North America will not be lucky this year, since the moon will be under the horizon. You can still watch a live webcast, however, if you are there.

But if the weather is favorable, most of East Africa, the Middle East and Central Asia should see the total lunar eclipse and total. Scientists in Antarctica should also have a magnificent view.

Europe, East Asia, Australia, Indonesia and other regions will enjoy a partial lunar eclipse, where the moon passes partly through the shadow of the Earth.

L & # 3939; Partial eclipse begins when the moon first touches the semi-darkness or the outer shadow of the Earth. According to NASA, this should happen at 5:14 pm, GMT, on July 27th.

The total eclipse – when the moon is fully inside the Earth's shadow with red highlights – starts at 19:30 UTC and ends at 21:13 UT. It's an hour full 43 minutes, which is just four minutes of the longest total lunar eclipse possible, according to EarthSky.

The partial eclipse will resume immediately after, because the moon will come out of the shadow of the Earth, and the entire event will be completed at 23:28 UTC (early July 28, according to the l '; where you live).