2024 YR4: Identification of Possible Precoveries in 2016 IPTF Data

TL;DR

This study searches for precovery observations of asteroid 2024 YR4 in 2016 survey data, significantly refining its orbit and reducing impact risk uncertainty for 2032, aiding planetary defense efforts.

Contribution

It presents the first identification of potential precovery observations of 2024 YR4 in 2016 data, improving orbit accuracy and impact risk assessment.

Findings

Potential precovery detections with high significance (Pnull = 5x10-9).

Orbit uncertainty reduced by over 300 times.

If confirmed, impact risk in 2032 can be definitively ruled out.

Abstract

2024 YR4 is a 40-100 meter-diameter asteroid and former Torino Scale 3 object which currently has a roughly 4% chance of impacting the Moon on 2032 December 22, an event which recent studies suggest could pose a hazard on Earth due to impact ejecta. We present a search for, and identification of, potential precovery observations of the virtual lunar impactor in Intermediate Palomar Transient Facility (IPTF) survey data, as well as other publicly accessible surveys, dating from 2016. These candidate detections, not accounting for any currently-undetected Yarkovsky forces, predict a perilune of 22001 +/- 49 km and a perigee of 277534 +/- 46 km (relative to the center of each respective body) representing an improvement of > 300 times in the approach distance uncertainty above the existing orbit solution and, if confirmed, decisively ruling out a lunar impact in 2032. Using a matched filter tuned to 2024 YR4's predicted appearance in each image, we find the detection to be significant at Pnull = 5x10-9. The resultant possible orbit solution should be easy to confirm during 2024 YR4's 2028 approach to Earth, potentially greatly reducing the effort required by the planetary defense community at large to characterize 2024 YR4 before its potential lunar impact.