Image from a NASA animation depicting an annular eclipse

February 15, 1999
Web posted at: 4:42 p.m. EST (2142 GMT)

(CNN) -- The last annular solar eclipse of the century will take place Tuesday over Australia and part of the Indian Ocean.

Solar eclipses occur when the moon passes between the Earth and the sun, blotting out the sunlight. In a total eclipse, the "disk" of the moon covers up the sun completely. In an annular eclipse, the moon blots out 98 percent of the sun, leaving a ring of sunlight visible around the dark lunar disk.

At the beginning and end of annularity, the sunlight streaking out from behind the disk can resemble a pearl-beaded necklace, an effect known as "Bailey's Beads."

The eclipse will occur between 6:03 a.m. and 8:45 a.m. GMT (1:03 a.m.-3:45 a.m. EST, with annularity at 7:29 a.m. GMT (2:29 a.m. EST). The annularity will be short-lived, lasting only 47 seconds.

The length of the entire path of annularity will be about 13,700 kilometers (8,494 miles), and it will cross into southwestern Australia about 300 kilometers (186 miles) north of Perth.

Although the eclipse will be nearly total, observers are cautioned that solar filters are still required even during the narrow annular phase. Direct viewing could lead to eye damage or even blindness.

The century's last total solar eclipse (not annular) will occur on August 11 and will be visible from Europe and West Asia.

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