The Near Earth Object Threat to Earth

Unverified NEO Rate Study

We have performed a preliminary study of the rate at which newly discovered NEOs are subsequently not verified by follow-up astrometry. A PDF file containing a copy of this study may be downloaded by clicking here. Feel free to print and distribute this report with proper attribution.

We use the terms "unverified", "unconfirmed", or "non-confirmed" to describe objects without proper follow-up astrometry. We do not use the term "lost" to describe such objects because a few of these objects each year turn out to be rocket boosters, cosmic ray hits on the CCD detector, or other non-NEO's.

The key results of the preliminary study are as follows:

• Overall, during the period February 2006 through December 2006, approximately 8% of all newly-discovered NEOs were lost.
• Loss rates increase as the target objects become fainter.
• Loss rates increase as the target objects move more rapidly.
• Loss rates during this period exceeded 15% for objects fainter than V=21 and approached 25% for very faint and rapidly moving objects.

Last modified: January 12, 2008.