The sun and moon aligned over the earth in a rare astronomical event on Sunday - an annular eclipse that dimmed the skies over parts of Asia and North America, briefly turning the sun into a blazing ring of fire.Eclipses of some type occur almost every year, but stargazers have not seen an annular - shaped like a ring -eclipse on U.S. soil since 1994, and the next one is not to occur until 2023. That is because the phenomenon requires a particular set of orbital dynamics, NASA Space Scientist Jeffrey Newmark said.An annular eclipse occurs when the moon's orbit is at its furthest point from the Earth and closer to the much larger sun. That juxtaposition allows the moon to block more than 90 percent of the sun's rays when the two orbs slide into alignment."It's like moving your fist in front of your eyes," Newmark said. "You can block out the view of a whole mountain. It's the same kind of effect."The eclipse was first visible over southern Asia and then moved across the Pacific. Traveling on diagonal path, the eclipse began its way across parts of Oregon, Nevada, Utah, Arizona and New Mexico, and was expected to disappear in Texas with the sunset.Day did not turn into night. But light faded as the moon slid in front of the sun, much like turning down a dimmer switch, and then slowly returned as the moon moved away.From start to finish, the eclipse was to be visible for just under two hours. A view of the so-called "ring of fire" spectacle at the eclipse's peak, however, was to last about four minutes, and even then was only visible to viewers positioned along the centerline of the eclipse's path.(Reuters)