-
- The Ojibwa, a native American tribe of
the Great Lakes region, tell the story of creation as a visit by a "long
tailed heavenly climbing star" " Genondahwayanung. Although
the visitor burned all life on Earth, Chimanitou (a Holy Spirit) warned
the Ojibwa to roll themselves in mud and they alone survived.
-
- The commonly held view by scientists
is that the nucleic acids which form the basis of life were synthesized
during an electrical storm. Another less known theory suggests acids were
not originally manufactured on our planet but imported. Although unlikely,
the idea that our biological building blocks are extraterrestrial in origin
is not impossible.
-
- To import the fragile acids of life from
anywhere outside Earth, one needs mobile chilled containers like the ice
cream trucks crisscrossing America. Of course, these are busy serving kids.
The next best thing to ice cream trucks for refrigerated space travel
are comets, also known as long tailed heavenly climbing stars. They have
small solid cores surrounded by a thick layer of ice naturally insulated
by the vacuum of outer space.
-
- Comets have held a special place in our
history. Whether spiritually, politically or scientifically, comets "
or our interpretation of the phenomenon known as comet " have steered,
enlightened, and affected our lives.
-
- Only a handful of comets are visible
to the naked eyes, such as Halley and Hale-Bopp, but the solar system
contains hundreds of thousands of comets, perhaps even millions. Most remain
invisible in a cloud ten thousand times further from the sun than Earth.
sunlight there is so faint it barely illuminates their relatively small
bodies. A comet is typically several miles in diameter, in contrast a
planet is thousands of miles in diameter.
-
- Comets become visible when a gravitational
disruption " such as the passing of a planet " ejects them from
their cloud and they are captured by the sun's gravitational field. They
then set on an elongated orbit which takes them within eyesight of Earthlings.
The orbit can take a few years to thousands of years to complete.
-
- The comet's tail always points opposite
the sun. This phenomenon led to the understanding that sunlight provides
a measure of pressure. As a comet approaches the sun, heat evaporates
its surface layer and sunlight pushes the evaporated ice into a long tail.
It is this outward pressure which " in the sun's interior "
stops the star from imploding under its own weight.
-
- Halley's comet was just as enlightening
for the theory of gravitation. When Newton first formulated his idea that
matter attracted matter, skeptics abounded. But in 1682, astronomer Edmund
Halley predicted the return of a comet based on Newton's theory. Seventy-six
years later, on Christmas Eve of 1758 the comet returned as predicted by
Halley, then dead for eleven years. It was the final confirmation that
gravitation indeed worked and this brought Halley's comet much fame.
-
- But comets had been famous well before.
The appearance of a comet has often been interpreted as an omen of some
sort. <!--In 1066, upon the appearance of a comet, Merlin advised Prince
Uter of Britain to invade Normandy " it was none other but comet
Halley. More-- Recently, a group of people chose to believe an alien spaceship
trailed comet Hale-Bopp and committed suicide as a way to enter the ship.
Somehow, comets find ways to disturb or inspire us.
-
- Halley's comet returned in 1910, close
enough for Earth to pass through its tail, and anti-comet pills became
as popular as anti-aging snake oil. In 1995, comet Shoemaker-Levy broke
up and parts of it fell on Jupiter. Suddenly, questions were raised about
the mortality of our species: What if it had been Earth?
-
- Recently, a new type of comet has surfaced
on pictures from NASA's Polar satellite. These comets are dozens of feet
in diameter instead of several miles and composed almost exclusively of
ice instead of ice, methane, and iron. Suggested ten years ago but rejected
then, the evidence seems to show that Earth is impacted by these objects
up to several thousand times a day.
-
- To explain these small comets, a second
comet cloud near Neptune has been suggested, and for disruption, an invisible
large planet that passes near it every 26 million years. It seems rather
unlikely to have one extra planet in our solar system conveniently invisible
and with such a radically different orbital period than all others. The
satellite pictures, however, seem difficult to deny.
-
- Again, comets disturb our views of the
solar system and even of the origins of life. While one comet loaded with
nucleic acids may not have been enough to start life on Earth, how about
a thousand a day? And if these small comets did import life to this planet,
how about other planets? Scientists are decidedly sounding more like storytellers,
and astrophysics like Native American folklore. Perhaps that should have
been our starting point.
|
