An Asteroid on the Brink

Asteroid 2953 Vysheslavia, a Koronis family member about 15 km in diameter, very close to the outer edge of the 5/2 Kirkwood gap, has been shown by numerical integrations to fall into the resonance; then it approaches Jupiter and ends up into a hyperbolic orbit. The typical dynamical lifetime is of the order of 10 Myr. This "marginally unstable" region of the orbital element space bordering the 5/2 resonance is only ≈ 10-3 AU wide in semimajor axis. Thus Vysheslavia has stayed in its current "dangerous" location in orbital element space for a time much shorter than the age of the Solar System. We discuss several hypotheses on the origin of this object, including a comparatively recent collision in the Koronis family and the possible implantation into a quasi-stable main-belt orbit of a stray body on a comet-type orbit. We conclude that physical observations are needed to discriminate among these possibilities.