Universal Ramblings

On July 21, there is a total Solar Eclipse at 5 degrees of sidereal Cancer in Pushya. This eclipse occurs in the 6th house for Washington, DC symbolic of health matters and service. It is perhaps not coincidental that the Obama administration’s planned reform of health care is likely to be front and centre around this time. As an added dimension of plausible astrological significance, the nakshatra of Pushya refers to “nourishing” and health improvement activities. Since eclipses often mean change or interruption of the status quo, we can see how the long-awaited reforms to the unwieldy American health care system may finally come to pass. At the same time, this eclipse features a fairly troubling square aspect between Venus (women, art, money) and Saturn (limits, loss, responsibility). Moreover, this occurs near the angles in the DC chart with Saturn sitting on the 7th cusp. At a general level, this would seem to be a difficult indication for the US economy since Venus is connected with money and prosperity. Venus also represents relationships so it is possible that the US may experience some turbulence with its traditional allies, perhaps over trade issues. Venus rules the 4th house (Taurus) and its wide conjunction with Mars will likely mean more setbacks in the housing sector. The close Mercury-Mars 3rd house aspect may bring issues of transportation and computing into focus, some negative and some positive.

The periodicity and recurrence of solar (and lunar) eclipses is governed by the Saros cycle. It is a period of approximately 6,585.3 days (about 18 years 11 days 8 hours.) When two eclipses are separated by a period of one Saros, they almost share the same geometry. The eclipses occur at the same node with the Moon at nearly the same distance from Earth and at the same time of the year, except that the eclipse’s path will moves a third of the way west and a little north, on the Earth’s surface from the last eclipse occurrence. Thus, the Saros is useful for organizing eclipses into families or series. Each series typically last about 12 to 13 centuries and contains 70 or more eclipses.

The total solar eclipse of July 22, 2009 is the 37th member of Saros 136. The first eclipse of this cycle began with a small partial eclipse on June 14, 1360 off the coast of Antarctica. Throughout the 20th century, Saros 136 continued to produce exceptionally long duration total solar eclipse, with tracks passing across the equator. The eclipse of May 29, 1919 was particularly noteworthy and interesting because it was the first solar eclipse used to measure the gravitational deflection of starlight by the Sun as predicted by Einstein’s general theory of relativity.

The June 20, 1955 total solar eclipse was particularly interesting to all of us here because it is the longest duration of all total solar eclipses belonging to the Saros 136 with a maximum duration of 7 minutes 8 seconds, and which passed over the Philippines, including Manila. This eclipse is the longest recorded total solar eclipse. The 2009 eclipse has a maximum duration of 6 minutes 39 seconds although it will occur in the Pacific Ocean. So I have decided to lead the ALP team to Wuhan, China as I think this is the best area to observe this eclipse although at the expense of a much shorter duration but with a better chance of clear sky during the eclipse duration.

As the partial eclipse progress, the temperature drops noticeably. This can also affect the focus of cameras and telescopes which should be checked once in a while as totality approaches.

The total phase of an eclipse is accompanied by the onset of a rapidly darkening sky whose appearance resembles evening twilight about half an hour after sunset. It gives an observer an excellent opportunity to view some planets as well as bright stars in the daytime sky.

A total solar eclipse is probably the best and most spectacular astronomical event that many people will experience in their lifetime! There is a great deal of interest in observing solar eclipses, and thousands of astronomers (both amateur and professional) travel around the world just to observe and photograph them.

A solar eclipse can offer us an opportunity to see a natural phenomenon that illustrates the basic principles of science and mathematics. Some examples are the use of pinhole cameras as well as telescopes or binoculars leads to an understanding of how optics work in these devices; the rise and fall of environmental light levels during an eclipse illustrate the principles of radiometry and photometry; the observation of how plants and animals behave during the eclipse’s entire duration; and, the monitoring of the rise and fall of temperature during the entire eclipse period, etc.

Observing the Sun, however, can be dangerous if proper precautions are not taken into account. The solar radiation that reaches the Earth’s surface ranges from ultraviolet (UV) radiation at wavelengths longer than 290nm to radio waves in the meter range.

The tissues in the eye transmit a substantial part of the radiation in between 380-400nm to the light sensitive retina at the back of our eye. While environmental exposure to UV radiation is known to cause accelerated aging of the outer layers of the eye and the development of cataracts, the primary concern over improper viewing of the Sun during an eclipse is the development of eclipse blindness or retinal burns. The result can be temporary or permanent, depending on the severity of the damage.

When one looks repeatedly, or for a long duration of time, at the Sun without proper eye protection, this can cause retinal damage accompanied by thermal injury – the high level of visible and near-infrared radiation causes heating that literally cooks the exposed tissue. This thermal injury destroys the rods and cones, creating a small blind area! The great danger to vision is significant because of the fact that the injuries occur without nay feeling of pain (the retina doesn’t have any pain receptors) and the visual effects do not become obvious for at least several hours after the damage is done! Viewing through the telescope and binoculars without proper filtration can result in immediate or instant eye damage because of the high irradiance level in the magnified image.

The only time that the Sun can be viewed safely with the naked eye is during TOTALITY only. It is NEVER SAFE TO LOOK AT THE SUN DURING PARTIAL OR ANNULAR ECLIPSES, OR PARTIAL PHASES OF A TOTAL SOLAR ECLIPSE!!!! So what are the safe ways or techniques to observe the solar eclipse?