The Geminid meteor shower peaks on Dec. 13th and 14th when Earth runs
through a stream of debris from a strange object that some astronomers
are calling a “rock comet.”
The 2012 Geminid meteor shower
peaks on the night of Dec. 13-14, The Geminids are a unique meteor
shower in that their identified parent body is not a comet, but what
seems to be an asteroid! Of the meteor showers with known parent bodies
studied by meteor scientists, the Geminids are the only shower to have
an asteroidal parent body; all others have a cometary origin. 3200
Phaethon measures 5.10 km in diameter which increases the ‘unique’
factor; considering the amount of debris we see, we would expect
Phaethon to be a much larger body!
Artist’s Concept of a Rock comet
Phaethon was discovered on October 11,
1983 using the Infrared Astronomical Satellite, and named after the
Greek myth of Phaethon, son of the sun god Helios, due to its close
approach to our Sun.
Phaethon is technically classified as an asteroid — the first to be
discovered via satellite. But how could an asteroid produce meteoroids
that cause the Geminids? One theory is that Phaethon broke apart from
another object, ejecting meteoroids as a part of the breakup. This
doesn’t agree with other things we know, however. Another theory is that
a collision with another object thousands of years ago could have
produced debris that Earth now travels through. This theory appears to
be unlikely as well, based on other evidence. Another theory assumes
Phaethon to be a dead comet (the spent nucleus of a comet whose ices had
been sublimated away) that produced debris in the past that now
intersects Earth’s orbit. But no evidence for mass loss from the object
has ever been reported…. until recently.
In 2009 the NASA spacecraft STEREO-A observed 3200 Phaethon to
brighten by a factor of two, quite unexpectedly. This brightening at
perihelion was likely due to a release of dust from the object, possibly
due to heating and cracking of the surface rocks as Phaethon came close
to the Sun. That brings us to the fourth theory, that Phaethon is a
rock comet. The problem with this theory is that it doesn’t account for
the amount of dust in the Geminid stream.
So what it comes down to is that the Geminid parent object is a mystery.http://beforeitsnews.com/space/2012/12/nasa-strange-object-debris-coming-will-hit-earth-december-13th-and-14th-2450296.html
