Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reiner Gamma swirl: magnetic effect of a cometary impact?

07.04.2006


This animation, made from images taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows a feature characterized by bright albedo, and called Reiner Gamma Formation.



The Reiner Gamma Formation, a totally flat area consisting of much brighter material than the surrounding dark ’mare’, is centred on an area located at 57.8° West, 8.1° North, in the Oceanus Procellarum on the near (visible) side of the Moon, and has an extension of approximately 30 by 60 kilometres.

The AMIE camera obtained the images on 14 January 2006, from a distance between 1599 and 1688 kilometres and with a ground resolution between 144 and 153 metres per pixel.


From early ground-based observations, this feature was initially misidentified as a crater. Only later detailed observations from orbit (such as those performed by USSR’s Zond-6, and NASA’s Lunar Orbiter, Apollo and Clementine missions) revealed its true nature: a very unusual morphology, consisting of swirl-like patterns that do not correspond to any topographic features.

Its main part consists of a bright pattern of elliptical shape, located to the west of Reiner crater. Bright elongated patches extend to the northeast in the Marius Hills region and small swirls extend to the southwest. The origin of the Reiner Gamma Formation and other swirls occurring on the lunar surface is still unclear.

Lunar swirls are associated with magnetic anomalies and some of these swirls – such as Mare Ingenii and Mare Marginis - are ‘antipodal’ to large impact structures (that is they are located right into opposite regions of the Moon globe).

So, it was suggested that the Reiner Gamma swirls correspond to magnetized materials in the crust or iron-rich ejecta materials able to deflect the solar wind (constant flow of charged particles coming from the Sun). This would prevent surface materials to undergo maturation processes, and so produce an optical anomaly.

However, Reiner Gamma Formation still stands as a particular case. In fact, the magnetic anomaly does not correlate with the scale of the lunar crust structure and large-scale anomalies seen on the far side. Furthermore, the anomaly is not associated with any obvious antipodal basin structure, and the surface material related to Reiner Gamma appears optically very immature (the age for its emplacement could be quite recent).

The analysis of NASA’s Clementine imaging data showed that the optical and spectroscopic properties of the local regolithic surface layer are close to those of immature mare crater-like soils. This is consistent with the properties of a shallow subsurface mare soil layer.

Considerations from works on impact cratering support the hypothesis that the uppermost part of the regolith could have been modified through an interaction with falling fragments of a low-density comet nucleus, previously broken by tidal forces and having ploughed the regolith.

Then, the magnetic anomaly would not be the result of an antipodal crustal field generated in the formation process of large impact basins. It would rather arise from local effects during the interaction between the lunar surface and cometary physical environment, with the possibility that the solar wind is locally deflected and contributes to the unusual optical properties.

So, the Reiner Gamma Formation could be an interesting site for future human exploration because of the radiation deflected from the surface. Further testing of this hypothesis requires access to the physical properties of the surface to constrain the mechanisms of formation of the lunar swirls. This is an ongoing task for the AMIE camera, aimed at studying regolith photometric properties.

Bernard H. Foing | alfa
Further information:
http://www.esa.int/SPECIALS/SMART-1/SEM05FNFGLE_0.html

More articles from Physics and Astronomy:

nachricht Heat flow through single molecules detected
19.07.2019 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Better thermal conductivity by adjusting the arrangement of atoms
19.07.2019 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>