# 1997-98NEW MEXICOHIGH SCHOOLSUPERCOMPUTINGCHALLENGE Interim Report

 Team Number: 103 School Name: Silver High School Area of Science: Astro-Physics Project Title: Moon Project Abstract: http://mode.lanl.k12.nm.us/97.98/abstracts/103.html Interim Report: http://mode.lanl.k12.nm.us/97.98/interims/103.html Final Report: http://mode.lanl.k12.nm.us/97.98/finalreports/103/finalreport.html

Our project deals with the moon and predicting the distance it will have drifted away from the earth at some point in time in the future. We have redefined the scope of our original project, in that we are no longer attempting to ascertain just what lessened effect the moon drifting away from earth would have on the magnitude of the the high tides. We decided to scrap this part of our project due to difficulties in finding a suitable formula for tidal prediction that related a change in the gross gravitational pull of the moon as it drifts away from earth to the magnitude in the tides. We did; however find formulas without this crucial variable. If our project were to be added on to in the future this would be one obvious and logical area of expansion. As for the our new modified project, we have written out an equation that describes the moonÕs motion as it drifts away from earth; however, it does assume that the moonÕs orbit is circular (the moonÕs orbit is actually elliptical), but this should not create very large errors in the calculation. The other thing we need to works out with this equation is the distance the moon has progressed beyond the point at which the high tides occur on earth. This is a little tricky as it has to be a variable which changes as the moonÕs pull on the earth changes. We should have this very soon though as we are going to get some books from a local astronomer that contain formulas and other such information on how to predict the moonÕs position in relation to earth, from which can find the point at which the high tide will be. Once we have this final piece of information the program will be fairly easy to write (it just needs to be one rather large ÒDO loop,Ó that will be repeated over and over again and there is no extremely complex math involved either). The process that causes the moon to increase in distance from the earth and we are mathematically modeling is as follows:
1) the moonÕs gravity causes a bulge in the earth corresponding with the position of the high tide
2) the earth and bulge rotate beyond the direct vertical line between the earth and moon
3) the increased mass of the bulge on the earth that is in front of the moon pulls the moon forward at a greater rate of speed.
4) thus, the moon, to compensate for its increased speed has to increase the size of its orbit.
We will be able to know if our equation is producing the correct information by comparing it with similar data that has already been compiled by variety of other sources. We will also be able to possibly reach a time in the future when the moon will be locked in a constant position over the earth due to the fact that this process also slows the earthÕs rotation in exactly the opposite manner that it speeds up the moons rotation around earth.