Matt Quandt
Assistant editor
Astronomy magazine
(t) 262.796.8776 x419
(e) mquandt@astronomy.com
September 28, 2005
WAUKESHA, WI — On October 3, observers in Spain, Portugal, and a large swath of Africa have the opportunity to view a spectacular annular solar eclipse. The word “annular” derives from the Latin anulus, which means ring.
On the 3rd, the Moon passes directly between the Sun and Earth. Because the Moon then lies fairly far from Earth, it appears too small to cover the Sun’s whole disk. Instead, observers along the central line will see a ring of sunlight surrounding the completely dark Moon — an annular eclipse. The zone in which observers will see the annular eclipse spans 138 miles (223 kilometers).
The annular eclipse will begin in the North Atlantic at 8h41m UT. Only 10 minutes later, it will reach the coasts of Spain and Portugal. At 8h56m UT, Madrid will be engulfed by the annular eclipse. In Spain’s capital city, the event will last 4 minutes and 11 seconds. The greatest duration of annularity — 4 minutes and 32 seconds — will occur when the Sun and Moon line up over central Sudan. The event ends over the Indian Ocean at 12h22m UT.
The last purely annular eclipse occurred May 31, 2003. (An annular/total hybrid eclipse occurred April 8, 2005.) The next annular eclipse will happen September 22, 2006, over parts of South America and Africa.
Use extreme caution when viewing the Sun. At no point during any annular eclipse is it safe to look directly at the Sun without a proper filter. Use an approved coated-glass or optical Mylar solar filter or a #14 welder’s glass.
Other October sky highlights:
