<p>a friend and I know a professor from cal tech (Professor of Planetary Science) that is willing to be our mentor, but we haven't even started on the project yet (due oct.1)</p>
<p>is it possible to make a decent project that can contend for a semi-finalist position (at least) from this short time frame?</p>
<p>As a current college research student and former Siemens Regional Finalist in the Siemens Competition, I would say that you are cutting it awfully close to the deadline if you begin your project sometime in the next week or two. Even starting today would be rather pressing because research doesn't just progress naturally out of thin air in a matter of a few weeks. Do you have any idea what you would be doing yet? If not, you probably don't want to enter Siemens. Research often leads to many unexpected things that just don't happen the way you expected them to (that is the beauty of it though and how you learn a whole lot). However, if you do have the opportunity to do some research with this professor (regardless of whether or not you enter Siemens), I would take that opportunity and see if research is something you're interested in pursuing. If you're not a senior, you can always enter Siemens next year and your project will probably have progressed quite a bit by then.</p>