Explanation:
On Wednesday, September 29, the Earth came within one million
miles of the
asteroid
Toutatis -- the closest predicted
aproach of our fair planet to a sizable asteroid or comet in this
century.
Coming within
one million miles or about 4 times the Earth-Moon
distance, Earth would appear to be nearly the size of the full
moon in the asteroid's sky, as suggested in this illustration.
In Earth's sky,
Toutatis appeared
only as a faint object rapidly moving against a
background of stars.
Also known as Earth-crossing
asteroid 4179,
Toutatis is in an eccentric 4 year orbit
which moves it from the asteroid belt between Mars and Jupiter to just
inside Earth's orbit.
When the Earth passed near it
in 1992 Toutatis was imaged
by radar and seen to be two irregularly shaped lumps,
perhaps joined by a narrow neck.
This bizarre object is up to 1.5 miles wide, 3 miles long, and is
tumbling through space.
Studies of Toutatis and other
Earth-crossing asteroids help reveal
connections between the
Solar System's
meteorites, main-belt asteroids and comets.
These asteroids also offer tantalizing
targets for robotic
exploration and, over time, represent
potential collision hazards
for planet Earth!