Principia's Astronomical Observatory joins several hundred observatories worldwide in providing position data for asteroids in our Solar System. Of special interest now are thousands of objects called Near Earth Objects or NEO's. In the blinking images here you see three images of the minor planet 1999HF1, which orbits the Sun in an elliptical path that takes it closer to and farther from the Sun that we are. The object, which shines at magnitude 16.5, is about 40,000 times dimmer than can be seen with the naked eye, was captured by our digital CCD camera with exposures of 120 second duration on July 12, 1999.