SOLAR ECLIPSE
A total solar eclipse occurs when the moon passes between the earth and sun, casting its shadow on the earth's surface. Total eclipses are not as rare as one might think; they actually occur almost once per year, but are frequently over an ocean or remote part of the globe. The solar eclipse on July 11, 1991, provided a treat for scientists, passing right over the bank of astronomical observatories atop Mauna Kea (about 14,000 feet elevation).
    For those of us below cloud level, however, it was a different story. Most of the Big Island was covered with clouds and showers on the morning of the eclipse. We were luckier than some, who merely got to watch an overcast sky grow darker and then lighter again.
    For a good explanation of how eclipses occur, and a description of what it's like to view a total solar eclipse (in good weather), check out this tutorial.