DXERS UNLIMITED
WEEKEND EDITION
SATURDAY, JUNE 16, 2001
By Arnie Coro CO2KK
Send your comments, questions and ideas to: arnie@radiohc.org
Hi amigos! Welcome to the weekend edition of Dxers Unlimited, your favorite
listener-oriented radio hobby show, ON THE AIR,VIA SHORT WAVE and on the
World Wide Web via our Dxers Unlimited
website, and now also available via our E-mail mailing list that
offers free subscriptions to our listeners...
I am Arnie Coro, radio amateur
CO2KK, your friend here in Havana, and here is item one: Dxers Unlimited's
special report, The first total solar eclipse of this millennium, this
century, and of course of year 2001... The actual eclipse will occur next
week on Thursday UTC day starting at exactly 10:35 UTC, and it will provide
scientists with a lot of valuable information because, by a very fortunate
coincidence, the number of sunspots will be much higher than originally
expected at this stage of the solar cycle...
Item two: Short wave listeners and radio amateurs that live in cities are having to deal not only with extremely high noise levels generated mostly by digital equipment, but also very stringent restrictions related to the installation of outdoor antennas, that's why stealth antennas are becoming more and more popular, from the classic flagpole vertical, to the very thin "invisible" wire... But now, artists are coming to the rescue!!!
Yes, you heard it right, amigos!!! Artists are joining efforts with engineers designing some very efficient antennas that have also beautiful modern art value... Today I'll tell you about one such AA or Artistic Antenna, a model that I have just finished testing here with excellent results...
And as always, at the end of the show Dxers Unlimited's exclusive and not copyrighted HF plus 6 meters propagation update and forecast will provide you with useful information to optimize your enjoyment of the hobby... Stay tuned for more radio hobby related information right on this same frequency, coming to you in just a few seconds after a brief musical interval...
This is Radio Havana Cuba, the name of the show is Dxers Unlimited and here is today's special feature in detail... This millennium's FIRST TOTAL ECLIPSE. Southern Africa on Thursday will host this week the first total solar eclipse of the Third Millennium, and as expected the eerie sight will be eagerly awaited by an army of scientists, astronomers and eclipse junkies, including, of course, radio amateurs and short wave listeners.
At 1035 GMT Thursday, on the solstice, the Moon will cross the face of the Sun, casting a shadow that will strike the southwestern Atlantic about 400 kilometers (250 miles) southeast of Uruguay.
Racing eastward, the shadow, called an umbra, makes landfall in central Angola at 1236 GMT before tracking across Zambia, the southernmost tip of Malawi, northern Zimbabwe and Mozambique and finally southern Madagascar before being swallowed at sunset in the Indian Ocean at 1331 GMT.
For those in the path of the "totality," the Sun will be completely obscured, appearing as a dark disc with a halo of blazing gold. The sky will briefly turn indigo, and the stars and planets suddenly appear. Birds and animals will fall silent or chatter or scurry about in confusion.
Then, a few minutes later, as if by a miracle the Sun, the bringer of life, will gradually reappear.
Not for nothing have eclipses bred fear and terror down through the ages, an event linked with the downfall of kings and the coming of war, plague, drought or famine. The first record of a solar eclipse dates back to 899 BC, according to bamboo inscriptions found in a royal tomb and deciphered by Chinese astronomers: "During the first year of King Yi, the day dawned twice at Zhang," a town near Xian, wrote the anonymous historian, obviously shocked as he chronicled the event.
Superstition may have yielded to rationalism, but there remains something wondrous about an eclipse that brings even the most placid scientist to a pitch of breathless excitement.
Among those travelling to Zambia is a team from Oxford's Rutherford Appleton Laboratory, eager to answer a riddle about the Sun's atmosphere. "The solar atmosphere has been the source of some mystery for more than half a century," team leader Ken Phillips says. "It is very hot, much hotter than the surface layers, and the question is: what is heating it?"
Phillips suspects bursts of energy, called nanoflares, cause this higher temperature, and wants to use high-speed recorders during the eclipse to test the theory.
This is something that normally either cannot be done or is hard to do on Earth. Zoologists, too, are interested in the response among wild animals. More than 200 wildlife enthusiasts will gather in Zimbabwe's Mana Pools National Park to see how elephants, hippos, baboons, lions, warthogs, bats and birds react to the sudden blackout and drop in temperature.
Most of the influx of people into the region will be thousands of amateur astronomers who travel around the world for each eclipse, proudly listing each celestial spectacular they have witnessed. A total solar eclipse occurs somewhere in the world about every 18 months.
The last such event was on August 11, 1999. It was unprecedented, for it crossed one of the most densely-populated swathes of the world, covering western Europe, the Balkans, the Middle East and southern Asia. Next Thursday, partial eclipses of the Sun will be seen from eastern South America and the southern two-thirds of Africa.
Total solar eclipses occur when the Moon comes between the Earth and the Sun, completely obscuring the solar disk for a few minutes. The eclipse follows a West-to-East track that lasts several hours until the alignment ends.
Total eclipses happen, as I said a while ago, about once every 18 months, although at least two partial or annular eclipses occur somewhere on Earth each year. Most eclipses occur over the sea or over largely uninhabited areas. The great total eclipse of August 11, 1999 was exceptional because it traversed such a populous area, from western Europe to India. The shadow of an eclipse travels at 1,770 kms (1,100 miles) per hour at the Equator, and up to 8,046 kms (5,000 miles) per hour at the poles. The width of the path of the eclipse at totality is at most 269 kilometers (167 miles). The record duration of a totality is seven and a half minutes.
Total eclipses happen because of a mathematical quirk, unique in the Solar System: a 400-to-1 ratio involving the orbit and size of the Moon and the size and distance of the Sun. It means that when, seen from the Earth, the Moon's 3,476-km (2,160-mile) diameter just about covers that of the face of the Sun, which is 1.4 million kms (870,000 miles) across.
BUT BEWARE... BELIEVE IT OR NOT:
Total solar eclipses will eventually stop, because the Moon is gradually drifting away from the Earth at the rate of one centimeter (0.4 inches) per year. When it is another 20,000 kms (12,500 miles) farther out, the moon's disk will appear smaller than the Sun's even at the closest point in its orbit. But that won't happen for another billion years.
Prepared 16-Jun-2001; transmitted 18-Jun-2001, 18:43 EDT
Arnie Coro CO2KK
Havana, Cuba
June 16, 2001
Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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