Chuck you wrote:
Also remember that many craters on the moon have been flooded with lava since they first formed. Some of them with central peaks had the peaks completely covered. They are still there, but buried under a sea of frozen lava. I read an article that purports the unusual case where Piton, a skinny mountain peak south of Plato, is a central peak. The creator rims have been flooded away by lava just leaving the central peak sticking up…cool. One comment on the water droplets. We always see them come in at 90 degrees or perpendicular to the water surface. I suspect that may play apart in moon cratering too. Those that obviously come in at an oblique angle seldom leave a central peak but something that looks more like a key-hole. Jim
--- On Wed, 1/28/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] More on Upheaval Dome To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Wednesday, January 28, 2009, 4:15 PM More from the depths of my memory. A water drop into a film, on a flat surface, will rebound in a ring, rather like a crown. No peak. A water drop into a deep puddle, will rebound a drop back up. Peak. So I'm surmising that you will get a central peak in a crater if the structure of the ground at ground zero has the proper rebound characteristics. This is probably at least as important as mass of the impactor. Also remember that many craters on the moon have been flooded with lava since they first formed. Some of them with central peaks had the peaks completely covered. They are still there, but buried under a sea of frozen lava. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com