From Earth, we can look up in ~ the Moon and also see several locations that appear darker than the rest. This darker regions make up the attributes of the “Man top top the Moon” the we space all so familiar with seeing. In this article, we discover what these dark spots space called and also how they gained there in the an initial place.

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What are the Moon’s Dark Spots made Of?

While the Moon’s dark point out look favor a ceiling of shadows, they space actually nothing of the sort. This shadowy illusion is due to the reality that over 80% that the Moon is consisted of of anorthosite. This gray material plays a big part in reflecting the Sun’s rays toward Earth.

When at an early stage scientists observed the Moon, they also wondered what these dark regions were. Believing lock were big bodies that water, these early on scientists gave them the name maria, which means “sea” in Latin.

Sea of Tranquility near Apollo Landing website 2. (Image credit: NASA)

The ax maria stuck around and is still in use today, along with oceanus (ocean), lacus (lake), palus (marsh), and sinus (bay).

In actuality, these dark areas are nothing of the sort. Contemporary study that the Moon has revealed these dark spots to be no water but large seas of dried lava. These areas of heavy basalt rock cover roughly 16% the the entire lunar surface, with the vast bulk being situated on the Earth-facing side of the Moon.

Basalt is normally darker in shade than anorthosite but also doesn’t reflect light virtually as well. This leaves it looking the black shade we’re used to see from Earth.

Where did the Moon’s Dark clues Come From?

We know that this day the Moon is a cold, dark, and also dormant system without any type of volcanic activity. In bespeak to recognize the origin of this lakes of solid lava, we have to jump backward gradually a couple of billion years.

During this time in history, the Moon to be at the height of its volcano activity. The Moon’s warm mantle (the layer under the surface) was complete of magma during that time.

This magma would certainly escape the mantle through volcanic eruptions and additionally through fissures in the crust where it to be the thinnest. It’s also possible that meteor impacts on the lunar surface ar shattered the crust, and also lava was able to an in similar way escape that way.

It’s additionally believed that the Earth’s heaviness played a component in the variety of eruptions that developed on the Earth-facing next of the Moon. This may explain why there room so many much more basalt lakes top top the close to side versus the other.

The Moon’s heaviness is much less than the of Earth. This provides it much less complicated for the magma to circulation out the the inside layers of the Moon. The lesser gravity additionally meant that it didn’t come shooting the end of the ground like we sometimes see on our planet. Rather, the flowed out favor a cup the runs over.

View of Schroeter’s Valley and crater Aristarchus photographed by Apollo 15. (Image credit: NASA)

In some of the shortest valleys of the Moon, this lava pooled, forming large seas the lava. It didn’t take lengthy for the molten basalt to permanently solidify right into the dark spots that we’re maybe to check out today.

Perhaps the most incredible currently of observing lunar maria is that you’re looking at rock that has actually existed in its current condition for upwards of 3 billion years.

How to be Maria Named?

All in all, there space 22 different maria ~ above the lunar surface, no to mention those designated together lakes, marshes, and bays. Every mare is forced to describe sea features, sea attributes, or a state of mind during the specify name process.

Moon Craters and also Seas. (Image credit: What The Puck top top Wikimedia Commons CC BY-SA 4.0)

When Mare Moscoviense was uncovered on the much side the the Moon by the previous Soviet Union, castle proposed the name Moscoviense after your capital, Moscow. This appeared to go against the standard naming convention, yet the International expensive Union declared it acceptable because Moscow is a “state the mind.”

Mare Tranquillitatis, also known as the Sea the Tranquility, was the site of the Apollo 11 landing. It would certainly go down in background as the first location the humanity ever before stepped foot on the Moon.

Lunar Rille

In numerous cases, lava flows left lengthy grooves ~ above the lunar surface ar as lock drained down into maria. These networks were provided the name rille after the German word because that groove. Lunar rille have the right to be several hundred mile in length and at the same time several miles wide.

View of Hadley Rille together photographed by Apollo 15. (Image credit: NASA)

Perhaps the most well known is Hadley Rille, wherein the Apollo 15 spacecraft made its landing. Gift the very first mission to have a lunar rover, the astronauts were able to explore the trench in some detail.

The biggest Dark clues on the Moon

Not all lunar dark clues were created equally. Part are quite small, with a diameter of around 30 mile (50 kilometers). None, however, compared to the big size the the s of Storms.

Oceanus Procellarum, or the ocean of Storms, consists a huge portion of the western edge the the Moon ~ above the side we view from Earth. This tremendous “ocean” covers more than 1,600 mile (2,500 kilometers) from north to south and covers 1,500,000 mi2 (4,000,000 km2). That’s end 10% that the entire surface area the the Moon.

An oblique view of a portion of the lunar nearside situated near the northeast sheet of the s of Storms (Oceanus Procellarum), photographed by astronaut Alfred M. Worden. (Image credit: NASA)

A sink of this dimension is unique on the Moon. Researchers today think that the s was created by a massive affect of some type either while lava to be still flow or just after it hardened.

Apollo 12 touched under within the large expanse well-known as the ocean of Storms. Several unmanned spacecraft have landed within Oceanus Procellarum. The most recent, Chang’e 5, accumulated a few pounds of rock samples native the site.

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The Moon’s dark spots tell a tale of a time as soon as the Moon was a much more active ar than it is today. Today the Moon may be dark and also cold, but we’re maybe to watch billions of years of background written anywhere its surface. Time will tell what other stories the Moon has waiting for us as we continue to check out our closestly neighbor.