Near the Edge of the Atira Orbital Realm: Short-term Dynamical Evolution of 2020 HA10 and 2020 OV1

Abstract

Atiras or Interior Earth Objects (IEOs) have their orbits contained entirely within the orbit of Earth. The first IEO, 1998 DK36, was found in 1998; out of the 23 known Atiras, 15 have been discovered during the last decade. Here, we provide a preliminary assessment of the current dynamical status and short-term orbital evolution of 2020 HA10 and 2020 OV1, two recently discovered Atiras. Our calculations indicate that 2020 HA10 periodically switches between the Aten and Atira orbital realms, and although it is almost certainly a present-day Atira, it spends most of the time following Aten-type orbits. In contrast, 2020 OV1 is well entrenched within the Atira orbital realm, but it might have arrived there relatively recently.