Comet D/1770 L1 (Lexell) made the closest observed pass by a comet to the Earth at approximately 0.015 AU on 1 July 1770. A naked-eye object observed by many astronomers of the time, it was subsequently lost: the best contemporary estimates had it removed from its 1770 orbit by Jupiter in 1779 and sent to the outer Solar System.Near-Earth asteroid 2010 JL33 has an orbit similar to that followed by Lexell's comet during its observed apparition. However, this NEA's nominal orbit, which is well-known on the basis of a decade-long arc which includes radar observations, does not approach the Earth at the correct time to be Lexell's comet. That is, unless modest non-gravitational forces are applied, in which case the famous near-miss can be reproduced.Modern measurements of 2010 JL33 together with those Lexell's comet made in the 18th century -which include motion exceeding 40 degrees per day on the sky at closest approach- provide exquisite constraints on the dynamical processes at work, cometary, Yarkovsky or other. I will discuss the implications of and the conditions required for asteroid 2010 JL33 to be, in fact, long-lost comet Lexell.
AAS/Division for Planetary Sciences Meeting Abstracts #47
- Pub Date:
- November 2015