Detection of Earth-impacting asteroids with the next generation all-sky surveys

TL;DR

This study simulates the effectiveness of next-generation all-sky surveys, like Pan-STARRS 1, in detecting Earth-impacting asteroids, highlighting their potential and limitations in early identification of dangerous objects.

Contribution

It provides a detailed analysis of the detection capabilities and challenges of future sky surveys for Earth-impacting asteroids, including the need for space-based observations.

Findings

Most impactors >140m will be detected during surveys

Objects with long synodic periods near the Sun may be missed

Space-based platforms could improve detection of interior-orbit impactors

Abstract

We have performed a simulation of a next generation sky survey's (Pan-STARRS 1) efficiency for detecting Earth-impacting asteroids. The steady-state sky-plane distribution of the impactors long before impact is concentrated towards small solar elongations (Chesley and Spahr, 2004) but we find that there is interesting and potentially exploitable behavior in the sky-plane distribution in the months leading up to impact. The next generation surveys will find most of the dangerous impactors (>140m diameter) during their decade-long survey missions though there is the potential to miss difficult objects with long synodic periods appearing in the direction of the Sun, as well as objects with long orbital periods that spend much of their time far from the Sun and Earth. A space-based platform that can observe close to the Sun may be needed to identify many of the potential impactors that spend much of their time interior to the Earth's orbit. The next generation surveys have a good chance of imaging a bolide like 2008TC3 before it enters the atmosphere but the difficulty will lie in obtaining enough images in advance of impact to allow an accurate pre-impact orbit to be computed.