The size distribution of Near Earth Objects larger than 10 meters

TL;DR

This study uses data from the DECam survey to accurately determine the size distribution of Near Earth Objects larger than 10 meters, revealing fewer small NEOs than previously estimated.

Contribution

First direct derivation of NEO size distribution from 10 meters to 1 km using a single observational dataset with synthetic implant efficiency analysis.

Findings

Approximately 4 million NEOs larger than 10 meters exist.

Fewer small NEOs are present than some earlier estimates suggested.

Results align with several other recent size distribution estimates.

Abstract

We analyzed data from the first year of a survey for Near Earth Objects (NEOs) that we are carrying out with the Dark Energy Camera (DECam) on the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory. We implanted synthetic NEOs into the data stream to derive our nightly detection efficiency as a function of magnitude and rate of motion. Using these measured efficiencies and the Solar System absolute magnitudes derived by the Minor Planet Center for the 1377 measurements of 235 unique NEOs detected, we directly derive, for the first time from a single observational data set, the NEO size distribution from 1 km down to 10 meters. We find that there are 10^6.6 NEOs larger than 10 meters. This result implies a factor of ten fewer small NEOs than some previous results, though our derived size distribution is in good agreement with several other estimates.