Comet LINEAR
Comets >
It’s time to dust off that pair of binoculars in the garage or that telescope you got for Christmas. We’re going comet hunting.
A long time ago in a galaxy... well... a galaxy right here as a matter
of fact, a monstrously big, swirling cloud of dust and rocks and gas formed
a disk. The center of this organizing Frisbee-like maelstrom became a
star - our sun.
Some rocky material near this star accreted into spheres of molten material
which would cool and become today’s inner planets. Farther out, where
it was a heckuvalot colder, water ice and gases could also be used as
building blocks to make planets - big, giant planets like Jupiter and
Saturn, Uranus and Neptune.
But really far out - I mean really far out - beyond all the planets, billions
of miles away where the dust and gas were very, very spread out, nothing
could seem to get close enough to other stuff to build anything substantial.
Even now, out where the sun barely shines, there is a bunch of planet-making
crud leftover from the beginning of the solar system.
Every once in a while, though, a chance meeting with another rock or the
gravitational influence of a distant passing star will nudge one of these
miles-wide icy rocks out of its lonely, distance orbit and into a trajectory
which will take it to the center of our system, towards the sun.
As this redirected "dirty snowball" makes its way closer to
the sun, it gets warmer. Now its frozen gases start to thaw and evaporate
away surrounding the infant comet in its own rapidly expanding atmosphere.
As it travels within Mars’ orbit, the solar winds emanating from
the sun gently brush back the gases and dust coming off the comet and
the "tail" is born. This is the familiar picture most people
have of a comet.
The last big comets to pass by were Hale-Bopp and Hyukatake several years
back. They were easily seen with the naked eye - Hyukatake’s tail
was hundreds of millions of miles long!
Behold, we have a new comet in the crowd, the last naked-eye comet of
the 20th century. Discovered in its infancy last year passing near Jupiter,
it is called LINEAR, after the research lab that found it.
During the month of July it will get closer and closer to the sun, its
tail getting brighter and brighter. But it will be a quick pass through
our area. In fact, by August the show will be over for naked eye observers.
That’s why it’s important you look this month if you want to
see it.
It rises this week in the constellation Camelopardis, in the wee, predawn
hours (see website below for sky map). If you don’t have astronomer’s
blood and instead find it necessary to see things at a more reasonable
hour, the 22nd is your date with destiny.
LINEAR is then in the constellation Ursa Major, an easy-to-find constellation
because it’s got that Big Dipper in it. About 10 PM, go outside,
armed with binoculars and look just "underneath" the Dipper.
If things go as scheduled Comet LINEAR should be right there waving at
you.
Enjoy it. There are no known naked-eye comets for the foreseeable future
although there is no doubt that many are on there way here from way, way,
way out there.
Until next time, clear skies!
Posted by Administrator at 2000.07. 9 09:27 AM | Comments (0)
