The Moon hides the Sun April 8
WAUKESHA, WI – People across much of the southern and eastern United States will have front-row seats for one of Nature’s more impressive spectacles: a partial solar eclipse. On Friday afternoon, April 8, the Moon will slide slowly in front of the Sun, eventually blocking up to half of our star from sight.
The view gets better the farther southeast you live. Those along a line running roughly from San Diego to Philadelphia will see the Moon take a mere nick from the Sun. Viewers from West Texas across the Gulf States will see at least 20 percent of the Sun hidden from view. And from the southern tip of Texas and the southern half of Florida, at least 40 percent of the Sun will be blocked. Miami residents have the best view of the partial eclipse, with nearly half the Sun covered.
Safe eclipse-viewing tips
The Sun still appears blinding even when half of it is hidden from view. No one should ever look directly at the Sun during a partial eclipse. Even a naked-eye view is dangerous, and looking through binoculars or a telescope without proper filters can cause blindness in less than a second.
That doesn’t mean you shouldn’t watch the eclipse, however – just need take the proper precautions. One safe method is to view the Sun indirectly by projecting its image. You’ll need two pieces of white cardboard, some aluminum foil, tape, and a stickpin. Cut a hole in one piece of cardboard and tape the foil over the hole. Then use the pin to poke a tiny hole through the foil. During the eclipse, stand with your back to the Sun and let sunlight pass through the pinhole and onto the second piece of cardboard, where a tiny image of the eclipsed Sun will appear.
You also can view the eclipse directly by using a safe solar filter. A #14 welder’s glass works fine – look for it at welding supply stores. Mylar or metal-on-glass filters sold through astronomy equipment suppliers will also allow you to view the eclipse safely.
You should never use a so-called “Sun filter” that screws into the eyepiece of a telescope. Also, avoid using sunglasses, CDs, smoked glass, photographic film, black plastic garbage bags, Mylar candy wrappers, or photographic neutral density filters. Although these materials may limit the amount of visible radiation that passes through, they do little or nothing to stop the equally dangerous infrared radiation.
South Pacific to enjoy best views
Although parts of the United States witness a nice partial eclipse, those farther south get a more spectacular view. Along a narrow track from east of New Zealand to northern South America, the Moon passes directly in front of the Sun. Observers near the center of this track will see the Moon block the whole Sun. Totality lasts for up to 42 seconds for those lucky enough to be on cruise ships in the South Pacific. Near the end of the track in South America, viewers can see an annular eclipse – where a ring of sunlight remains around the pitch-black Moon. The maximum for this “ring of fire” occurs in Venezuela and lasts 34 seconds.
So-called hybrid eclipses – total over part of the central track and annular over the rest – are the rarest type of solar eclipse. Approximately 35 percent of all eclipses are partial, where the Moon blocks only part of the Sun at maximum. Another 32 percent are annular, and 28 percent are total. That leaves just 5 percent as the hybrid type that’s visible April 8. The last such solar eclipse occurred 18 years ago.
Fast facts:
Matt Quandt
Assistant editor
Astronomy magazine
(w) 262.796.8776 x419
mquandt@astronomy.com
April 6, 2005