Mercury's 'Spider' Pantheon Fossae Formation Linked To Asteroid Impact

ScienceDaily (Sep. The Caloris Basin is the youngest-known large impact basin on Mercury. 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. 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. 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. Professor Jim Head, of Brown University, Rhode Island, and co-investigator of the MESSENGER mission believes that the Pantheon troughs could also have be...
Originally from: http://www.sciencedaily.com/releases/2008/09/080923084541.htm