Good news for stargazers this week: another beautiful supermoon will rise over San Francisco. The second Supermoon for this year will occur tonight, September 17, at 7:34 pm PST. This Supermoon is especially exciting because it is also a partial lunar eclipse.
The partial lunar eclipse will reach it’s peak at 7:44 pm and end just two hours later. The eclipse is partial, so only the top 8% of the moon will be in shadow. Meanwhile, the Supermoon will peak at 7:34 pm, tonight, so we definitely recommend finding a spot to stargaze if you can.
What is a Supermoon?
Supermoons appear especially large and bright in the sky, leading to the unofficial name “Supermoon.” According to Nasa, the larger and brighter appearance is due to the full moon coinciding with the moon reaching its closest point to the Earth during orbit, called the perigee. The result is a moon that appears 30% brighter and 14% larger than its counterparts. September’s Supermoon is the second out of four this year, so if you don’t have a chance to see this one, there’s still plenty of time. This Supermoon, along with October’s, is the closest to Earth of the year, so it promises to be a pretty spectacular sight.
What is a Lunar Eclipse?
A lunar eclipse occurs when the Earth, sun, and moon line up, resulting in the Earth’s shadow falling on the moon. Today’s lunar eclipse is only a partial one, so just a portion of the moon will be in shadow.
What is the Harvest Moon?
This full moon falls closest to the autumn equinox, which makes it a Harvest Moon. The name goes back hundreds of years, with the first known use in 1706.
Make sure to check out the full moon this evening along with the partial lunar eclipse. If you happen to miss this full moon, next month also has a Supermoon on October 28.