GoKawiilAmateur astronomers use DIY telescope rigs to measure asteroid shapes via star occultations
A hobbyist describes using a modest, low-cost telescope setup—including a 130-millimeter Newtonian scope, a motorized equatorial mount running the open-source OnStep controller, and a GPS-timed flasher for calibration—to observe asteroid occultations, when an asteroid passes in front of a distant star and briefly blocks its light. By timing these fleeting shadow events, amateur observers can help map an asteroid's shape and size, work that is difficult for large observatories to do alone.