The surface of the moon.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The surface of the moon. Urey, Harold C. Abstract The planetesimal 100 km in radius which collided with the moon, forming Mare Imbrium, contained iron-nickel alloy objects some kilometers in dimensions which produced the grooves in the moon's surface and gre~ silicates which formed radiating ridges as far from the collision area as the grooves. The Mare Nectaris planetesimal contained larger objects. It is suggested that these objects were raised to a high temperature on their surfaces in the presence of cosmic gases which reduced iron oxides and caused the formation of an iron shell some distance below the surface. Black ridges of the Imbrium system west of Copernicus may be unreduced primordial planetary material. The order of fall of planetesimals forming the maria was apprnximately Foecunditatis, Nectaris, Crisium, H umorum, Serenitatis and Imbrium. All but the last contain no large craters and Imbrium none in the area of collision. The depths of lava produced were 10 to 15 km. The time of formation was about I0~ years, judging from the time required for lavas to cool through a layer of pumice. The Mare Serenitatis planetesimal fell from the vertical, produced the black lavas of Tranquillitatis and was covered by the grey lavas of Imbrium. The entire process occurred at the terminus of the formation of the moon and its surface has been modified only slightly since. University of Chicago. Chicago, Illinois, Publication: The Astronomical Journal Pub Date: 1952 DOI: 10.1086/106644 Bibcode: 1952AJ.....57...27U full text sources ADS |