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Asteroid 1999 AN10 January 26, 1955 Prediscovery image of asteroid 1999 AN10 taken from the Digital Sky Survey. The faint streak is the trail left by the asteroid. The image has been contrast-enhanced.

Developed jointly by teams at JPL (Steve Pravdo, Principal Investigator)and Goddard Spaceflight Center (Thomas McGlynn), the system can be used to search for and display "pre-discovery" observations. That is, incidental recordings of asteroids that were not noticed at the time, but may be of objects later "discovered." Such positional measurements extend the data arc and can greatly reduce statistical uncertainties in the orbit solution. A search routine within SkyMorph takes advantage of the up-to-date database of near-Earth objects maintained by the NASA Near-Earth Object Office at JPL and the JPL Horizons on-line ephemeris systems developed by Jon Giorgini.

The 1999 AN10 case provided an example of the possible use of SkyMorph, also high-lighting some incidental bad luck in positioning. Initially discovered by the LINEAR observing program in New Mexico, an initial search by SkyMorph found no pre-discovery images until the 1955 trailed image was separately identified by German amateur astronomers, Gnadig and Doppler.

Commenting on the prototype system's functioning in the 1999 AN10 case, Pravdo noted that initially SkyMorph was looking at the center of the plate and a circle of radius 3 degrees around that center for the position of the object. This left out the square corners of the plate where the image of 1999 AN10 was located. This problem was quickly fixed and now the entire plate is included in the automatic search.

Interested users may access SkyMorph at:

http://skys.gsfc.nasa.gov/skymorph/skymorph.html

Once the object 1999 AN10 is specified and a search requested for the Palomar Sky Survey, users can call up the 1955 pre-discovery image via this web interface. This search engine will become increasing useful as additional Near-Earth Objects are discovered.

Jon Giorgini and Don Yeomans
NASA Near-Earth Object Office (NASA/JPL)