EastBay Today

Posted August 18, 2017

Going (Partially) Dark

What you need to know about the Aug. 21 solar eclipse

A solar eclipse will cut a path along the entire U.S. on Aug. 21, something that hasn't happened in over 100 years. The Bay Area will see a partial eclipse.

Thousands of years ago, in the land known as Mesopotamia, a solar eclipse plunged the ancient world into darkness. In response, the Mesopotamians forced a farmer to act as the king’s proxy. Within the next 100 days, just to make sure the bad luck associated with the phenomena would pass without affecting the true king and his subjects, the farmer was killed. 

But the Mesopotamians weren’t the only ancient civilization to experience shock and awe in the face of sudden shadows.

In Greece, during the 585 B.C. battle between the king of Lydia and the king of Medes, an eclipse darkened the sky above the warring armies. By the end, the soldiers of both sides had put down their weapons, declared the battle over and effectively ended the war.  

And this Monday in the Bay Area, thousands are expected to leave their desks, homes and schools to flock outdoors, as mesmerized and fascinated as ancient people were, by the passage of the moon between the earth and sun.

“Solar eclipses throughout history have been very mysterious and exciting,” said Cal State East Bay Lecturer Stephen Asztalos. “It has to be because everyone realizes that the sun is so vital for human life. And even though we understand what causes [eclipses] these days, there’s still an angst and a concern about ‘suppose [the sun] didn't’ come back.’”

Asztalos and fellow astronomy professor Amy Furniss have spent the past month leading up to the Aug. 21 event by giving interviews and presentations at local libraries about the eclipse, explaining what causes them and sharing what people should know about watching.

Here are their insights and tips:

What makes this eclipse unique?

Asztalos: Even though the eclipse is rather muted in the Bay Area, it is cutting a path along the entire U.S., something that hasn’t happened in over 100 years.

What does a partial eclipse mean?

Furniss: In the Bay Area we will be able to see what’s called a partial eclipse. That means when the moon comes between the sun and earth it will only partially cover the sun. It’s as though the moon is photo-bombing the sun.

How long does an eclipse last?

Furniss: A full eclipse—where the sky goes completely dark—lasts just a few minutes. But in the Bay Area, where we will be experiencing a partial eclipse, it will last about two-and-a-half hours from 9 -11:30 a.m., with the peak happening at 10:15 a.m.

But how dark will it actually be?

Furniss: If you’re in an area experiencing a full eclipse, you’re going to notice it getting significantly darker. Animals will start doing what they’d be doing if it was twilight and cars driving on the freeway are going to have to turn their lights on. In the Bay Area, it will get a little dimmer, but nothing crazy. The sun will be 75 percent covered, but that’s still pretty bright.

What did ancient peoples think about eclipses?

Asztalos: The most popular explanation was that a culture's sun god was being visibly affected by something negative. That a deity [who] was a permanent fixture in the sky could be made to disappear was generally cause for panic.

How can I view the eclipse?

Asztalos: You can do one of two things — pick up a pair of eclipse glasses (do not use regular sunglasses or look directly at the sun, even if it’s partially or fully blocked), which will allow you to look at the sun. Or, if you don’t have the glasses, take a piece of paper and poke a pinhole in it. When you hold the paper above the ground, it will create a sort of lense and allow you to see an image of the sun on the ground.

What if it’s cloudy?

Furniss: If it’s cloudy, you won’t be able to see the eclipse, but there will be live video streams online from other places where it is visible. 

Where can I get more information about the eclipse?

Furniss: I will be at the Pleasant Hill Library (1750 Oak Park Blvd, Pleasant Hill, CA) from 9 a.m. to noon Aug. 21, talking with people stopping by about the eclipse and passing out 1,000 eclipse viewing glasses. Additional information — including a map and live video — is available online.