Dear Friends and Students of NEOs:
As we approach the beginning of the new millennium on Monday, I
remind you that this will also be the bicentennial of the discovery
of the first asteroid or minor planet. At approximately 8 pm local
time on January 1, 1801, the asteroid Ceres was discovered at
Palermo, Sicily, by Giovanni Piazzi. Piazzi, like many astronomers
of his day, believed there was a missing planet between Mars and
Jupiter, in the “gap ” first noted by Johannes Kepler two centuries
previously. Piazzi followed the motion of the new “planet” for 41
days, providing enough information to demonstrate that it was
orbiting the Sun within this gap. It was subsequently named Ceres
for the patron goddess of Sicily in the ancient Roman pantheon. And
yes, Ceres is “as big as Texas”, with a diameter of nearly 1000 km.
Today tens of thousands of asteroids have been identified within the
asteroid belt between Mars and Jupiter, but Ceres remains the largest
by a considerable margin. These main-belt asteroids are also the
source of most of the near earth objects (NEOs) that interest us, in
part for their potential to impact our planet.
Like the beginning of the new millennium on January 1, 2001, this
anniversary does not seem to have captured very much public interest.
However, there will be a celebration at the Palermo Observatory. As
part of that event, MIT planetary astronomer Richard Binzel will be
delivering an address at 8 pm on January 1 to commemorate the
discovery. His address: “Asteroids Come of Age” is already published
in Science 289, page 2065.
Best wishes for the twenty-first century and the third millennium.
David Morrison
+++++++++++++++++++++++++++++++++++++++++++
David Morrison, NASA Ames Research Center
Tel 650 604 5094; Fax 650 604 1165
david.morrison@arc.nasa.gov or dmorrison@arc.nasa.gov
website: http://space.arc.nasa.gov
website: http://astrobiology.arc.nasa.gov
website: http://impact.arc.nasa.gov
