New understanding of the mystery of the Moon

Observations from Japan's Moon SELENE (Kaguya) spacecraft are opening new insights into the complex geological differences between the near face and the far side of the Moon.

So far there has been no breakthrough, but new data is expected to provide many clues for researchers.

It is only at the dawn of the human cosmic era can a glimpse of the other side of the Moon, always out of view from the Earth due to synchronous orbit - the time of the Moon orbiting the axis equals the time it spins around the Earth.

When the spacecraft was launched to observe the part that had always been in the dark for a long time, the scientists discovered that the Moon had two distinct faces : the close face was covered with a dark and smooth volcano marina The ancient has hardened), while the far side almost has absolutely no characteristics, but instead is covered with bright and rugged material.

Differences in topography and chemical composition show that the two evolutionary faces are different for more than 4 billion years of the Moon's existence.

SELENE's equipment provided detailed lunar maps of the Moon, as well as measuring and observing gravity changes and what was beneath the surface. These observations are detailed in a series of studies in Science magazine on February 13.

Different paths

The most popular theory about the formation and development of the Moon is a Mars-sized object that collided with the Earth before the solar system began to form around 4.5 billion years ago, in part. The Earth's crust breaks, eventually falling into orbit around the Earth and being cooled for millions of years, forming the Moon.

The first moon was covered by a deep sea of ​​magma, cooled down and hardened into a shell. Space rocks repeatedly hit the surface of the Moon until 3.8 billion years ago.

The decomposition of some elements in the Moon's crust creates heat that flows the surrounding rocks and stimulates volcanic phenomena. Since then, maria is formed, appearing as dark markings on the surface of the Moon.

A certain imbalance occurs that makes the face near and far away of the Moon grow differently, and the near face has much more maria. Whether the imbalance is the result of some huge impact or some internal change is still an unanswered question.

The results of SELENE obtained helped solve this problem.

Harder, cooler

SELENE measured unusual gravity on the far side of the Moon, and researchers were able to compare this result to the near side.

The gravity model of the distance confirms that it has a lithosphere (the outer shell of any moon or planet rock) that is harder and cooler than the near face during the period of the main effects, Gregory Neumann said. He is a member of NASA's Goddard Space Center at Greenbelt, Md. And did not participate in SELENE research group.

There is a hard and cold lithosphere that shows an internal cause that forms the difference between the two parts of the Moon, one is warmer and more flexible than the other.

The spacecraft also uses a laser altimeter to create the highest-resolution Moon topography ever. Neumann commented: 'It is wonderful'.

This map also shows that the shell of the distal surface is hard and therefore lacks water and other volatile compounds, factors that make up the elasticity of the Earth's crust.

Volcano

SELENE's observations also provide new insights into the early volcanic phenomenon of the Moon. A radar device could penetrate the surface of the Moon and indicate that there are crumbs between some volcanic basalt streams, which means that the phenomenon of volcanism stops and starts in the early Moon.

A fourth study, also published in detail in Science, states that the volcanic phenomenon on the far side of the Moon lasts longer than previously thought, although not as long as in the near side.

Model experts will be able to use the data collected from the SELENE study to build a more complete picture of the creation and development of the Moon gate.

Although this SELENE data adds a picture of the geology of the Moon, 'we still don't have big breakthroughs', for example, the ice hidden in the Moon crater, Neumann said.

Other spacecraft, such as China's Chang'e-1 and India's Chandrayaan-1, and future spacecraft, such as NASA's upcoming Moon spacecraft (Neumann is A member), will continue to gather new knowledge about the confusing history of the closest neighbor of the Earth.

(Photo: wikipedia)