[meteorite-list] Unexpected Vesta News

[Sterling K. Webb]

http://www.aanda.org/index.php?option=com_content&task=view&id=735&Itemid=277&lang=en_GB.utf8%2C+en_GB.UT

"Astronomy & Astrophysics is publishing a new
study of the orbital evolution of minor planets
Ceres and Vesta, a few days before the Dawn
spacecraft enters Vesta's orbit. A team of astronomers
found that close encounters among these bodies
lead to strong chaotic behavior of their orbits,
as well as of the Earth's eccentricity. This means,
in particular, that the Earth's past orbit cannot
be reconstructed beyond 60 million years. Although
small, Ceres and Vesta gravitationally interact
together and with the other planets of the Solar
System...  these effects do not average out.
Consequently, the bodies leave their initial orbits
and, more importantly, their orbits are chaotic,
meaning that we cannot predict their positions...
Last but not least, Ceres and Vesta gravitationally
interact with the Earth, whose orbit also becomes
unpredictable after only 60 million years. This
means that the Earth's eccentricity, which affects
the large climatic variations on its surface, cannot
be traced back more than 60 million years ago."

Free acces to the full article can be found at:
http://www.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/0004-6361/201117504&Itemid=129

Those sneaky minor, er,  dwarf planets! You can't
tell what they'll get up to next!


Sterling K. Webb