Sunday 22 November 2020

10 years of moon pics: NASA explains why moon shines in red, blue and even purple

Moon has since forever been the most beautiful jewel of the night sky on Earth. The planet’s constant companion undergoes a cyclic change in its appearance, all thanks to the periodic reflection of light of the Sun. 

This change in shape, however, is not the only different form that the moon takes in the night sky.

As you might have noticed, the moon has lately been observing a completely different colour than its usual grey. This, however, is not the only colour change that the moon displays. In fact, an astrophotographer has managed to capture the various shades of moon experienced by the observers on Earth over the last 10 years. NASA now clears that these changes in colour shades are caused by the Earth’s atmosphere.


In a recent post shared by the US space agency, a picture depicts the several shades of the moon, ranging from Purple to Red and even Blue. In the post, NASA says that although the moon appears to be “brown-tinged gray” from space, Earth’s atmosphere can have varying effects on the same, making the moon appear different from its real colour.

At times, it appears red, as NASA explains that “a red or yellow colored moon usually indicates a moon seen near the horizon.” This is because the blue light gets scattered over the long distance it takes for the moonlight to reach from the horizon to Earth’s surface, thanks to the atmospheric particles on the way, including dust.

The rare Blue moon, on the other hand, lights up the night sky when there are larger dust particles present in the atmosphere. This means that light from the Blue spectrum can reach the surface without getting dispersed on the way.

It is yet unclear as to how the moon turns Purple but NASA guesses that it should be “a combination of several effects.”

Different shades of the Moon (Image: Marcella Giulia Pace)

Among the collection, the last image portrays the total lunar eclipse of 2018 July. During the eclipse, the moon which was covered in the Earth's shadow, appears to be a faint red. The reason for this is cited to be the “light refracted through air around the Earth.”

The images have been collated by Marcella Giulia Pace, a primary school teacher and an astrophotography enthusiast in Italy. It took Pace 10 years to capture all the shades of the moon as seen in the image.

In its post, NASA explains that the next full moon, known by some as the Beaver Moon, will occur at the end of this month until it goes back to its new moon stage by the middle of December.

(Source: India Times)

No comments:

Post a Comment