Tacoma residents have a pretty good reason to look up tonight: A near-total lunar eclipse is expected to transform the full moon as it passes through Earth's shadow.
The eclipse will reach a maximum of 96% totality, meaning almost the entire lunar surface will be covered by Earth's shadow. At its peak, only a thin portion of the moon will remain outside the darkest part of the shadow.
And unlike a solar eclipse, you won't need special glasses to watch it.
The entire eclipse event runs from approximately 7:35 p.m. Thursday until 12:01 a.m. Friday, although the earliest stages may be difficult or impossible to see from Western Washington because the sun will still be up and the moon will be close to the horizon.
The show should get much better after sunset.
The eclipse is expected to reach its peak at about 9:12 p.m. Pacific Time Thursday, according to Space.com. Just a few minutes later, at approximately 9:18 p.m., August's full moon will reach peak illumination in Washington.
That means Tacoma sky watchers won't need to stay up until the middle of the night to catch the best part.
As the moon moves into Earth's umbral shadow, it should become noticeably darker and take on a reddish-orange color. It won't technically be a full "blood moon," because that term is generally reserved for a total lunar eclipse, when the entire moon enters Earth's darkest shadow.
But at 96%, Thursday's eclipse should come pretty close.
Why does the moon turn red?
The color comes from the same basic phenomenon that gives us colorful sunrises and sunsets.
During a lunar eclipse, Earth moves between the sun and moon, blocking most of the sunlight that would normally illuminate the lunar surface. Some sunlight still passes through Earth's atmosphere, where shorter wavelengths of light are scattered while more red and orange light makes its way through.
That filtered light reaches the moon, giving it the coppery or reddish appearance associated with lunar eclipses.
NASA has described the effect as though all of Earth's sunrises and sunsets were being projected onto the moon at once.
No special equipment required
One of the nice things about a lunar eclipse is how easy it is to watch.
Unlike a solar eclipse, you can safely look directly at a lunar eclipse with the naked eye. No eclipse glasses, filters or other protective equipment are necessary.
You don't need a telescope either. Binoculars or a telescope can provide a closer look at the moon as Earth's shadow moves across its surface, but they're completely optional.
The bigger challenge for Tacoma viewers may simply be finding a dark enough spot — and hoping the clouds cooperate.
For the best view, find an area with a clear view of the sky and as little artificial light as possible. Getting away from streetlights and other city lighting should make the changes in the moon easier to appreciate.
It's also the Sturgeon Moon
Thursday night's eclipse coincides with August's full moon, traditionally known as the Sturgeon Moon.
The name comes from the abundance of sturgeon that historically could be caught in the Great Lakes around this time of year, according to the Old Farmer's Almanac. Sturgeon were also an important food source for Native Americans.
But for Tacoma residents Thursday night, the name probably won't be the main attraction.
If the weather cooperates, start watching after sunset and plan to be outside around 9 p.m. The eclipse reaches its maximum at approximately 9:12 p.m., giving Tacoma a chance to watch 96% of the full moon slip into Earth's shadow without having to travel anywhere — or even stay up particularly late.
There’s more in today’s Tacoma Local Minute.
Catch the rest of today’s local news, events, and updates in the full issue here.