Planetary Society Grant Recipient Tracks Intriguing Near Earth Object

Frank Zoltowski, a recipient of a Planetary Society Gene Shoemaker Near Earth Object (NE0) grant, has helped determine the future orbits for asteroid 1999 AN10, which is expected to pass within 200,000 kilometers (about 120,000 miles) of Earth in 2027. The asteroid has excited great interest since it has the potential to approach Earth even closer in 2044 and 2046. None of the close approaches are considered threatening. An amateur astronomer, Zoltowski conducts a search for NEOs and asteroids in the small town of Woomera in the South Australian outback. The Planetary Society grant money enabled him to upgrade his CCD camera to a more sophisticated system, improving his ability to detect NEOs and do confirmation of their orbits. "The performance of my new CCD is spectacular. With it I have been able to get many objects 1999 AN10 included that I wouldn't have had a chance of imaging with my old CCD," said Zoltowski. Zoltowski conducted followup observations of asteroid 1999 AN10 that enabled researchers at the Minor Planet Center, the international clearing house for data about asteroids and comets, to develop more precise future orbital calculations for the object. The NEO was first discovered by the Lincoln Near Earth Asteroid Research (LINEAR) program, which conducts sky searches using an Air Force telescope at the White Sands Missile Range in New Mexico. Researchers in Italy Andrea Milani, Steven Chesley and Giovanni Valsecchi established the asteroid's initial orbital calculations. When researchers in the northern hemisphere were no longer able to track the object, Zoltowski in Australia was asked to track the object's passage through the southern hemisphere. He "recovered" (found) 1999 AN10 in April, 1999. The object has been a source of interest and concern since its orbit intersects Earth's so closely. However, researchers maintain that the chances of 1999 AN10 actually striking Earth are extremely low. Andrea Milani in his abstract reporting on the orbit calculations noted, "We have developed a theory which successfully predicts the 25 possible [near Earth] returns [of 1999 AN10] up to 2040. We have also identified six more close approaches resulting from the cascade of successive returns. Because of this extremely chaotic behavior, there is no way to predict all possible approaches for more than a few decades after any close encounter, but the orbit will remain dangerously close to the orbit of the Earth for about 600 years."