Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mare Humorum: where craters tell the story of basalt

10.07.2006
This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.

AMIE obtained the top frame on 1 January 2006, from a distance of 1087 kilometres from the surface, with a ground resolution of 98 metres per pixel. The remaining two frames were taken on 13 January 2006, from a distance of about 1069 (centre) and 1050 kilometres (bottom) from the surface, with a ground resolution of 97 and 95 metres per pixel, respectively.


Mare Humorum, or 'Sea of Moisture', is a small circular mare on the lunar nearside, about 825 kilometres across, filled with a thick layer of mare basalt, (possibly exceeding 3 kilometres in thickness at the centre of the basin). Mare Humorum is a scientifically interesting area because it allows the study of the relationships among lunar mare filling, mare basin tectonics, and global thermal evolution to the major mascon maria – that are regions of the moon's crust which contain a large amount of material denser than average for that area.

The area shown in the top image is centred at a latitude of 40.2º South and longitude 25.9º West; the centre image is centred at a latitude of 40.2º South and longitude 27.3º West; the bottom image is centred at a latitude of 40.2º South and longitude 28.8º West.

Mare Humorum, or 'Sea of Moisture', is a small circular mare on the lunar nearside, about 825 kilometres across. The mountains surrounding it mark the edge of an old impact basin which has been flooded and filled by mare lavas. These lavas also extend past the basin rim in several places. In the upper right are several such flows which extend northwest into southern Oceanus Procellarum.

Mare Humorum was not sampled by the Apollo program, so its precise age could not been determined yet. However, geologic mapping indicates that its age is in between that of the Imbrium and the Nectaris basins, suggesting an age of about 3.9 thousand million years (with an uncertainty of 500 million years).

Humorum is filled with a thick layer of mare basalt, believed to exceed 3 kilometres in thickness at the centre of the basin. On the north edge of Mare Humorum is the large crater Gassendi, which was considered as a possible landing site for Apollo 17.

Mare Humorum is a scientifically interesting area because it allows the study of the relationships among lunar mare filling, mare basin tectonics, and global thermal evolution to the major mascon maria – regions of the moon's crust which contain a large amount of material denser than average for that area (Solomon, Head, 1980).

Past studies (Budney, Lucey) revealed that craters in the mare Humorum sometimes excavate highland material, allowing to estimate the thickness from below the mare cover. Thanks to this, it was also possible to determine that the ‘multiring’ structure of the Humorum basin has a diameter of 425 kilometres (results based on the US Clementine global topography data).

In general, the chronology of lunar volcanism is based on the analysis of landing site samples from the Apollo and Luna missions, from the study of the relationship between the stratigraphy (layering of deposits) in different regions, and from the analysis of lunar craters – how they degraded over time and how their distribution in number and size varies over the Moon’s surface. From crater statistics, in the year 2000 Hiesinger and colleagues found that in Humorum there was a peak of eruptions at about 3.3-3.5 thousand million years ago.

Bernard H. Foing | alfa
Further information:
http://www.esa.int/SPECIALS/SMART-1/SEMVMAA6CPE_0.html

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>