Astrophysics authors/titles “new” September 22, 2013Posted by sandyclaus in Drake Revisited.
 arXiv:1309.4838 [pdf, other]Mass Extinction And The Structure Of The Milky WayM. D. Filipović, J. Horner, E. J. Crawford, N. F. H. TothillComments: Accepted for publication in Serbian Astronomical JournalSubjects: Galaxy Astrophysics astro-ph.GA; Earth and Planetary Astrophysics astro-ph.EPWe use the most up to date Milky Way model and solar orbit data in order to test the hypothesis that the Suns galactic spiral arm crossings cause mass extinction events on Earth. To do this, we created a new model of the Milky Ways spiral arms by combining a large quantity of data from several surveys. We then combined this model with a recently derived solution for the solar orbit to determine the timing of the Suns historical passages through the Galaxys spiral arms. Our new model was designed with a symmetrical appearance, with the major alteration being the addition of a spur at the far side of the Galaxy. A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events. Furthermore, we identify five additional historical mass extinction events that might be explained by the motion of the Sun around our Galaxy. These five additional significant drops in marine genera that we find include significant reductions in diversity at 415, 322, 300, 145 and 33 Myr ago. Our simulations indicate that the Sun has spent ~60% of its time passing through our Galaxys various spiral arms. Also, we briefly discuss and combine previous work on the Galactic Habitable Zone with the new Milky Way model.