Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mercury's "spider" Pantheon Fossae formation linked to asteroid impact

23.09.2008
As NASA’s MESSENGER spacecraft prepares for its second flyby of Mercury, new analyses of data from the first flyby will be presented at the European Planetary Science Congress in Münster on Tuesday 23rd September.

Dr Sean Solomon, MESSENGER’s Principal Investigator, will present a model that suggests that the origin of the Pantheon Fossae, a radiating web of troughs located in the giant Caloris Basin, is directly linked to an impact crater at the centre of the web.

The Caloris Basin is the youngest-known large impact basin on Mercury. The basin was discovered in 1974 during Mariner 10’s flyby, but the centre of the basin had not been seen until MESSENGER’s first flyby on 14th January.

MESSENGER revealed that the crater’s interior appeared to have been flooded by volcanic material in a similar way to the lunar mare basins. A ring of troughs was observed around the circumference of the basin. However, the biggest surprise was the discovery of radiating pattern of troughs, initially dubbed “the spider” by the team, which was unlike any structure seen in lunar basins or elsewhere on Mercury.

The troughs are hundreds of kilometres in length and the central crater, named Apollodorus after the architect of the Pantheon temple in Rome, is about 40 kilometres across. Several models have been proposed for their formation, including uplift of the basin due to heating from below, pressure building up from the superposition of surrounding plains or inward crustal flow. However, to date, none of these models could explain the radial pattern observed.

Dr Solomon and colleagues developed a three-dimensional model of deformations in Mercury’s crust in the Caloris basin and then modelled the effect of an asteroid impact at the centre.

“We found that stresses building up within the crust could explain the troughs found around the circumference of the basin but not the radial web at the centre. When we modelled the effect of a meteorite striking the centre of a pre-stressed basin floor, we found that the formation of the crater relieved the stress build-up and weakened the central area, allowing the troughs to spread out like cracks in a windscreen,” said Dr Solomon.

As the crater appears to be superimposed over the troughs, it appears that the Pantheon network formed simultaneously with the Apollodorus crater.

However, not all scientists agree that the crater’s presence at the centre of the web is anything more than coincidence.

Professor Jim Head, of Brown University, Rhode Island, and co-investigator of the MESSENGER mission believes that the Pantheon troughs could also have been caused by volcanic activity. An upflow of magma at the centre of the basin could have formed a reservoir at depth and a radial network of dykes.

“The first MESSENGER flyby provided a lot of evidence that volcanism has played an important role in Mercury’s history, in particular around the Caloris Basin. We found what appears to be a shield volcano located just outside the Caloris Basin and the area is surrounded by smooth plains, relatively free from impacts, which suggests a young surface. Given the amount of volcanic activity we’re discovering in that area, I wouldn’t want to rule out a volcanic cause just yet. Maybe MESSENGER’s second flyby will help us solve the mystery,” said Prof Head.

Anita Heward | alfa
Further information:
http://www.europlanet-eu.org

More articles from Physics and Astronomy:

nachricht NASA mission surfs through waves in space to understand space weather
25.07.2017 | NASA/Goddard Space Flight Center

nachricht A new level of magnetic saturation
25.07.2017 | Georg-August-Universität Göttingen

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: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>