Catlin, That is the original Nemesis theory. A geologist noticed that extinction cycles appeared to be periodic and came up with the idea of a "wandering" companion star as an explaination. It appears that his time scale was a little off, however, and his 'theory' has thus lost alot of it's following. There is Proxima Centuri however, a dwarf that is about 2 light years out, and I don't think it's path has been discussed much, nor to my knowledge has it been tied in with the origin of the metalic elements of which the theory states that metals originate within a star. When a star 'Novas' the metalic elements are pushed outward to neighboring solar systems. This appears to be an obvious oversight, but I'm not up with the most recent scientific theories - they may be discussing it. "What me worry?" - The Alfred E. Neuman character from Mad Magazine. pidjy, I look forward to it! I'll have to get my decimal places and other notation in order, it appears. On another thread, In a Forum far far away, bloodsong asked about the differences in notation regarding decimal points and I was amazed to see all the differences between countries. Dr. Robert Merrell, my geologic map interpretation teacher, once stated that one should always use terms others can understand, and be ready to clearly define terms you use. I try to do this, but sometimes my language is not clear or I leave something out. Also largely I depend on memory which introduces inaccuracies and omissions. cheers, - TJ - TJ