Get Ready for a Rare Solar Eclipse
The moon is endlessly creative in finding ways to amuse us. Just two weeks ago, the Earth’s only natural satellite was unusually close to us, and looked bigger and brighter than normal. The result was a Supermoon, which dazzled skywatchers across the U.S.
Now its orbit has taken the moon farther away than average, just in time it to pass directly in front of the sun on Sunday, fittingly enough. Ordinarily, that would cause a total solar eclipse, with the moon blotting out the sun entirely for a few minutes. But the moon appears smaller than normal — small enough, in fact, that it can’t block the entire sun, even when they’re lined up perfectly.
During the annular eclipse, the moon passes directly in front of the sun, leaving a spectacular ring of fire. Credit: ChinaFotoPress/Getty Images.
So instead, the lucky folks who live in a swath of the country from Northern California into Nevada will see what’s known as an annular eclipse on Sunday, late in the afternoon, the first visible in the U.S. in 18 years — weather permitting, of course. What it means is that when the moon is dead-center in front of the sun, a fiery ring of sunlight will surround the moon’s silhouette (“annulus” is Latin for “ring”).
“I like to compare different types of eclipses on a scale of 1 to 10 as visual spectacles," said NASA's Fred Espenak of the Goddard Space Flight Center on the agency’s eclipse website. “If a partial eclipse [where the moon crosses the sun off-center] is a 5 then an annular eclipse is a 9." (His ranking for a total solar eclipse on that same 1-10 scale: “A million! It’s completely off the charts.”
One note of caution: even though the moon will cover 94 percent of the sun on Sunday, there’s still enough light to blind you. Use an approved solar filter if you want to take a look, or, suggests Espenak, “A #14 welder's glass is a good choice.” If you’ve got one lying around, that is.