Kamikazes
from the Vasty Deep
Our son alerted my wife and me to the Leonid meteor
shower a few weeks before it was scheduled to occur.
As the date drew nearer, occasional sound bites on the news began
cropping up. The Internet indicated
that the shower would peak at 3 AM Mountain Time on the morning of November 18th.
But let me pause and offer some background
information to those not heavily versed in things celestial.
The Earth orbits the Sun, along with eight other planets.
But the planets are only the tip of the iceberg!
Countless asteroids, clouds of dust and many comets also whirl around our
Solar Star. Many of these objects,
particularly comets, take several decades to complete a single orbit.
Halley’s comet, for example, takes on average about 76 years.
It could be viewed in 1986, sweeping through the night sky toward the
mighty Sun, only to whip around it and start another 76-year journey out beyond
Pluto (the most distant planet). I
read somewhere that Mark Twain was born when Halley’s comet was visible in the
sky, and died when the comet returned.
Comets might be described as conglomerations of dirt
and ice. Yes, water (and lots of it)
does exist out there in space. There
are those who believe that much of the Earth’s oceans originated with comets,
caught in the infant Earth’s gravitational pull and slowed to crash-speeds as
they entered Earth’s atmosphere.
In any case, much of the stuff that makes up comets
is loose aggregate, sort of like gravel thrown up into the air.
In deep space the individual granules move in orbits around a comet’s
solid core or nucleus under the influence of the core’s gravitational pull.
Collectively the loose stuff forms something of a halo around the core.
As the comet approaches the Sun, however, this loose
aggregate rearranges into something resembling a tail (for reasons to be
explained shortly). And a fraction
of the particles in the tail actually break free from the core’s gravitational
grip, laying carpets of debris down as the comet sweeps around the Sun.
A common misconception is that the tail trails the
comet as it speeds through space. But
that is not in fact the way things work. Our
Sun not only radiates prodigious amounts of light, but it also spews out tons of
material particles every second. (The
tiny fraction that passes through Earth’s magnetic field is what causes the
Aurora Borealis, or “Northern Lights” here in the Northern Hemisphere.)
This swarm of very fast-moving particles, streaming out from the Sun and
into space in every direction, is collectively referred to as “The Solar
Wind.”
Now as a comet approaches the Sun and encounters a
Solar Wind of ever-increasing intensity, the Solar Wind begins to push the
comet’s halo of loose aggregate particles out away from the Sun.
So in truth the comet’s tail always points away from the Sun!
Well, that’s enough background information!
What about the Leonid meteor shower?
This event is brought to us courtesy of the Tempel-Tuttle comet.
It turns out that some of the debris trails (laid down by the comet) and
the Earth’s path (in our yearly trip around the Sun) intersect.
Since the particles of the debris field are traveling, relative to Earth,
many times faster than a high power rifle bullet, they are literally vaporized
by the tremendous heat of friction that’s generated when they enter our
atmosphere.
As one of these tiny drops of mineral and ice
plummets through the outer reaches of our planet’s atmosphere, it glows
briefly and leaves a ghostly trail of luminescence behind.
It becomes what we romantically refer to as a shooting star.
But far from being mighty stars, these particles are almost always no
larger than a single grain of sand. It
never ceases to amaze me that something that small can create such a dazzling
show of light!
My wife and I have a hide-a-way up near The Grand
Canyon, at 6000 ft. elevation. We
live in Mesa, Arizona, which gets very hot in the summer, and we spend
practically every weekend between May and October up there where it is much
cooler. The skies at those
elevations are very clear at night, and stargazing is excellent.
Normally if we see a single shooting star on any given evening, it’s a
memorable event.
But when the debris field of a comet passes through
Earth’s atmosphere, one might expect to see hundreds of shooting stars in less
than an hour! That is why these
relatively rare occurrences are called “meteor showers.”
The Leonid meteor shower is one of the most spectacular.
Since one of this magnitude isn’t expected to occur again until 2099,
we thought it might be worth making the trip up to the higher elevations to
watch it. On the other hand, it’s
a 3-½ hour drive up from the Phoenix area, and we were going up the following
Wednesday for a long Thanksgiving weekend. So
we debated whether to go. We decided
to watch things from Mesa, where the viewing would not be nearly as good due to
metropolitan smog, city light pollution and so forth.
Saturday afternoon the sky began to cloud over, and
it looked like we might not see anything at all if we stayed in Mesa.
So at 5 PM we hit the road, arriving at our place up north by 8:30 PM
Saturday night.
We went straight to bed, setting the alarm clock for
2:15 AM. (Remember, the experts said
that peak viewing would occur at 3 AM.) I
was awake before 2:15 and walked out onto the front deck.
I was astonished! Meteorites
were already streaking through the sky!
“It’s show time!” I shouted, rushing back
indoors to get bundled up. (Yes, in
mid November the nights are chilly at 6000 ft.)
My wife, Marge, got into her own down parka and we settled down out on
the back deck where there’s a nice swing with seating for three.
We scrunched down and rested our heads on the swing’s back, so as not
to get cricks in our necks, and began to watch the show.
With increasing frequency the meteorites streaked across the sky.
“There’s one!” Marge would cry.
“There’s another!” I’d answer.
In the space of an hour we no doubt saw more shooting stars than we’ll
see again in the remainder of our lives. It
was an amazing, once-in-a-lifetime display!
It’s now Sunday morning, and I’m writing this up
here in the high country where we spent the night.
It’s a beautiful day outside. After
being up for two hours plus in the middle of the night, we slept in this morning
and didn’t rise until the Sun was well up in the sky.
As I drift back mentally to what we saw last night
... hundreds upon hundreds of tiny visitors from outer space, burning up in
Earth’s atmosphere ... and as I think about the turmoil among men even as I
write these words, it’s clear that there is much to ponder.
The Universe is so vast, and we are so insignificant in the greater
scheme of things. Taking the big
view, the madness that occurred on September 11’Th here in our own tiny bubble
of space would seem comical and even ridiculous, if it weren’t so tragic.
Will we survive as a species, long enough for our
descendants to travel out among the stars, perhaps to discover and colonize real
new worlds (and not simply new continents here on our mother planet)?
Your guess is as good as mine. Suffice
it to say that I’m glad my wife and I made the trip up here, where clear night
skies are the norm, and didn’t decide to wait for the next display in 2099!
The Leonid meteor shower was an awesome production
put on, in my opinion, by an infinitely awesome Producer.
With luck it might be hoped that freedom and human rights will, in time,
be enjoyed by all the men, women and children of planet Earth.
And if and when that happy day arrives, then hopefully there will be
enough of God’s bounty left for us to fashion mighty galleons that embark on
voyages out among the stars. Stay
tuned, humanity. The best may be yet
to come!