What is inside the Moon?/ The mystery that still plagues scientists

2023-08-14 14:19:00, Kuriozitete CNA

Earth has given us some surprises lately. Scientists discovered that the inner core of our planet is actually a sphere with a composition that occasionally stops spinning, and then starts spinning the other way.

But the interior of the Moon is much more than a mystery. Beneath its cratered crust, the Moon's mantle rests on top of what scientists think is a partially molten layer, where clues to the formation of Earth's satellite may be found.

But according to a new study, there may not be any liquid layer beneath the Moon's surface. If future data confirm new modeling by researchers from Germany, the Czech Republic and the US, the lunar mantle may be solid throughout its surface, without a layer containing any molten material as theorized until today geoscientists.

Depending on the correct interpretation of the Moon's interior, future findings may restore or reconfirm our knowledge of the Moon's interior and how it formed. At this stage, both a molten midsection and a solid midsection are still a possibility for what the Moon's interior contains.

This is based on the limited geological data available to us. After the latest study, researchers say more samples from the moon are needed to solve this mystery.

Mikaela Valterova, a planetary scientist at the German Aerospace Center in Berlin, and other researchers tried to strengthen our understanding of the Moon's interior based on existing data, prevailing theories and some new ideas.

They compared two different models of the lunar interior to see which one actually explained the measurements we made of the Moon's shape and motion. The satellite orbits the Earth at an average distance of 384,400 kilometers. From there it exerts its attractive force on the Earth, causing tides in the oceans.

These effects depend strongly on the internal density, viscosity and hardness of the Moon.

But the pull of gravity goes both ways, and the Moon periodically deforms. By studying these rhythmic cycles and measuring the Moon's precise shape and motion using the lunar laser range, scientists can infer what its interior might be like.

2 scenarios are possible. "Apparently, the interior of the moon is hot, and a small portion of it may be molten, forming a thick layer of generally weak material buried more than 1,000 kilometers deep beneath the surface of the moon"- write Valterova and colleagues in their study.

This model was created when geoscientists tried to match strange measurements collected by a group of lunar seismic stations deployed by the Apollo missions that were operational from 1972-1977. Combined with other seismological data on the Moon's tidal effects, they thought the best way to explain their observations was with a partially molten, viscous layer at the Moon's core-mantle boundary.

This molten layer, they reasoned, could dissipate tidal energy and seismic waves in a way that matched periodic patterns in the data. But the findings of the new analysis by Valterova and colleagues suggest another explanation is possible.

"According to the second scenario, there is no molten layer, and the measured deformation of the Moon can be explained by the behavior of solid rocks at relatively low temperatures" - explain the researchers. However, the two possibilities cannot be distinguished from each other with the existing data.

So we have to wait and see what any possible future exploration of the Moon will bring. For now, we have a deeper understanding of what might lie beneath the surface of Earth's satellite, but many unanswered questions still remain./ Adapted from CNA