Possible tally stones at Mnajdra, Malta

This article describes the investigation of the orientations of the temple complexes of Malta and Gozo, which date from the period 3600-2500 B.C. It was accepted only those axes that were clearly axes of symmetry, and which were directed towards an entrance with a view of the terrain external to the temple. 15 such axes were identified, and it was found that the orientations of the axes were far from random. Indeed, with one exception, they faced in a southerly direction, between 125.5° and 2040 azimuth. The exception is Temple I at Mnajdra, Malta.peer-reviewe

Asteroids and Comets

Asteroids and comets are remnants from the era of Solar System formation over 4.5 billion years ago, and therefore allow us to address two fundamental questions in astronomy: what was the nature of our protoplanetary disk, and how did the process of planetary accretion occur? The objects we see today have suffered many geophysically-relevant processes in the intervening eons that have altered their surfaces, interiors, and compositions. In this chapter we review our understanding of the origins and evolution of these bodies, discuss the wealth of science returned from spacecraft missions, and motivate important questions to be addressed in the future.Comment: 84 pages, 27 figures. To be published in Treatise on Geophysics, 2nd edition (G. Schubert, Editor-in-Chief), Volume 10 (T. Spohn, Editor