Asteroid 87 Sylvia has two moons!
http://space.com/scienceastronomy/050810_asteroid_trio.html
Hum,
The word on the street says that there is already an asteroid called (10386) Romulus....
http://cfa-www.harvard.edu/iau/lists/MPNames.html#R
http://img.photobucket.com/albums/v328/blobrana/news/romulusremus.gif
Paper: astro-ph/0509830
Date: Tue, 27 Sep 2005 23:42:39 GMT (272kb)
Title: Eclipse Prediction and Orbit Improvement for Asteroids: Theory and
Application to Near Earth Asteroids
Authors: P. Tricarico, N. C. Hearn, G. Lake, G. Worthey
Categories: astro-ph
Comments: 14 pages, 2 tables, 8 figures, submitted to ICARUS
\\
Asteroids can be eclipsed by other bodies in the Solar System, but no direct
observation of an asteroid eclipse has been reported to date. We describe a
statistical method to predict an eclipse for an asteroid based on the analysis
of the orbital elements covariance matrix. By propagating a set of Virtual
Asteroids to an epoch correspondent to a close approach with a Solar System
planet or natural satellite, it is possible to estimate the probability of a
partial or total eclipse.
The direct observation of an eclipse can provide data useful to improve the
asteroid orbit, especially for dim asteroids typically observed only for a few
days. We propose two different methods: the first, based on the inclusion of
the apparent magnitude residuals into the orbit's least squares minimization
process, capable of improving the asteroid's nominal orbit and the related
covariance matrix; the second, based on weighting different Virtual Asteroids
in relation to their apparent magnitude during the eclipse, useful for recovery
purposes.
As an application, we have numerically investigated the possibility of a Near
Earth Asteroid eclipsed by the Moon or the Earth in the 1990-2050 period. A
total of 74 distinct eclipses have been found, involving 59 asteroids. In
particular, the asteroid (99942) Apophis has a probability of about 74% to
enter the Moon's penumbra cone and a probability of about 6% to enter the umbra
cone on April 14, 2029, less than six hours after a very close approach to
Earth.
\\ ( http://arXiv.org/abs/astro-ph/0509830 , 272kb)
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