Elimination of a virtual impactor of 2006 QV89 via deep non-detection

TL;DR

The paper presents a method using deep imaging to eliminate impact risk from near-Earth objects by non-detection of virtual impactors, demonstrated on 2006 QV89 with VLT observations.

Contribution

It introduces a targeted deep imaging approach to rule out impact threats from virtual impactors without needing to recover the actual object.

Findings

Virtual impactors can be precisely localized for effective observation.

Deep non-detection can conclusively eliminate impact risk.

Method successfully applied to 2006 QV89, removing its threat.

Abstract

As a consequence of the large (and growing) number of near-Earth objects discovered, some of them are lost before their orbit can be firmly established to ensure long-term recovery. A fraction of these present non-negligible chances of impact with the Earth. We present a method of targeted observations that allowed us to eliminate that risk by obtaining deep images of the area where the object would be, should it be on a collision orbit. 2006 QV89 was one of these objects, with a chance of impact with the Earth on 2019 September 9. Its position uncertainty (of the order of 1 degree) and faintness (below V$\sim$24) made it a difficult candidate for a traditional direct recovery. However, the position of the virtual impactors could be determined with excellent accuracy. In July 2019, the virtual impactors of 2006 QV89 were particularly well placed, with a very small uncertainty region, and an expected magnitude of V$<$26. The area was imaged using ESO's Very Large Telescope, in the context of the ESA/ESO collaboration on Near-Earth Objects, resulting in very constraining a non-detection. This resulted in the elimination of the virtual impactor, even without effectively recovering 2006 QV89, indicating that it did not represent a threat. This method of deep non-detection of virtual impactors demonstrated a large potential to eliminate the threat of other-wise difficult to recover near-Earth objects