What's on the other side of the moon?

Looking up at the silver orb of the Moon, you may be able to recognize familiar shadows and shapes on his face from one night to the next. You see the same view of the moon that our first ancestors followed after sunset.

Only one side of the spherical Moon is never visible from the Earth – it was not until 1959, when the Soviet spacecraft Luna 3 gravitated around the Moon and sent images to the house that human beings were able to to see the "far side" of the Moon for the first time. time.

A phenomenon called tidal lock is responsible for the consistency of the view. The Earth and its Moon are nearby and thus exert an important gravitational force. These tidal forces slow rotations of both bodies. They locked the Moon's rotation in synchronization with its orbital period relatively soon after its formation – following a collision between an object of the size of Mars and the proto-Earth, 100 million years after the fusion of the solar system.

Now, the Moon travels around the Earth at the same time as it takes to rotate around its own axis: about 28 days. From the Earth, we always see the same face of the Moon; from the moon, the earth remains motionless in the sky.

The near face of the Moon is well studied because we can see it. The astronauts landed near the moon to communicate with NASA here on Earth. All samples of Apollo missions come from the near side.

Although the hidden face of the Moon is not visible from our point of view, and with all due respect to Pink Floyd, it is not accurate to call it the dark side of the Moon. All sides of the moon live night and day as we do here on Earth. All parties have the same number of days and nights during a month. A lunar day lasts about two terrestrial weeks.

With modern satellites, astronomers have completely mapped the lunar surface. A Chinese mission, Chang & # 39; e 4, is currently exploring the Aitken Basin located on the other side of the Moon – the first mission of this type in the region. The researchers hope that Chang & # 39; e 4 will help answer questions about the characteristics of the crater surface and check if things can grow in lunar soil. Beresheet, a privately funded Israeli mission, began as a mission to compete for the Google Lunar X Prize. Although it crashed during a landing attempt earlier this month, the Beresheet team still won the Moon Shot Award.

Being protected from civilization means that the dark side of the moon is "dark radio". Researchers can measure weak signals from the universe that would otherwise be embedded. Chang & # 39; e 4, for example, will be able to observe a low-frequency radio light from the Sun or beyond, impossible to detect here on Earth because of human activities, such as television and radio broadcasts, and Other forms of communication signals. Low frequency radios go back in time to the very first stars and black holes, allowing astronomers to better understand how the structures of the universe began to form.

Mobile missions are also exploring all sides of the Moon as space scientists prepare their future human missions, calling on the resources of the moon to help humanity reach Mars. For example, the water – discovered by NASA's LCROSS satellite under the north and south poles of the moon in 2009 – can be broken down into hydrogen and oxygen and used for fuel and breathing.

The researchers are getting closer to exploring the polar craters of the moon, some of which have never seen the light of day – literally. They are deep and in the right place to never let the sun shine on the floor of the crater. There are certainly dark parts of the moon, but the farthest part does not actually belong to it.

Wayne Schlingman, Director of Arne Slettebak Planetarium, State University of Ohio

This article is republished from The Conversation under a Creative Commons license. Read the original article.