Pacific Science Center
Bringing science to life.
PacSci-Doku: “Partial Eclipse Only”
By Dennis Schatz – Senior Advisor
Do you Sudoku? It’s one of the hottest number games around! Well, here’s a twist we think you’ll love. We call it PacSci-Doku. Can you guess why? Here’s how it works. Instead of filling in the blanks with numbers, we use letters. Hidden in one of the columns or rows is the answer to a science question. You’ll find information about the answer on the answer tab below.
The question in this edition is:
Where do you have to be in the Moon’s shadow to only see a partial solar eclipse?
To find the answer, complete this PacSci-Doku using the following nine letters:
U A E Z R P M B N
Puzzle Difficulty: Easy
The Solution
The question in this edition is:
Where do you have to be in the Moon’s shadow to only see a partial solar eclipse?
The answer: Penumbra
On August 21, the Moon will be aligned with the Sun so that the Moon’s shadow passes across the surface of the Earth. Because the Sun is a million miles across, its shadow has two sections – the umbra and penumbra – see diagram below.
A person located in the umbra section of the shadow will see a total solar eclipse, where the Moon covers the entire Sun. The umbra is only about 65 miles across in August, so relatively few people will see the Sun totally covered. But everyone in the U.S. will be in the penumbra part of the shadow and will see a partial solar eclipse. Learn more about the upcoming eclipse by downloading this free 8-page Eclipse Observing Guide.