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Sci-Tech

Blood moon set to haunt the sky tonight

An unusual total lunar eclipse happening early Wednesday morning US time will turn the moon a coppery red and lucky watchers may even see a simultaneous sunrise and moonset.

Blood moon
This still from a NASA video shows a blood moon. Video screenshot by Amanda Kooser/CNET

Strange happenings will be afoot in the night sky in the morning hours of October 8. Our normally yellowish lunar companion will blush during a total eclipse. This eclipse is the second in a tetrad of eclipses visible in the US. It started in April with the first of the series of four total eclipses in a row. The moon this time will appear just slightly larger than it did in the spring.

The eclipse will begin at 2:15 a.m. PT. After a couple of hours, the total-eclipse part of the celestial show will begin and last 59 minutes. It will be best viewed from regions along the Pacific Ocean. The most notable feature of the blood moon, and the phenomenon that gives it its scary nickname, is the coppery red color it takes on. This is caused by the Earth's shadow falling over the moon as it blocks out the sun; light passing through Earth's atmosphere, sunset-like, gives the moon a reddish glow.

Some lucky moon watchers will be in for a special treat during this eclipse. A rare atmospheric effect could cause a selenelion. This allows you to see both the sun rising and the mid-eclipse moon setting at the same time.

It may be visible from certain areas on the eastern end of North America, though there is a short window of opportunity and it requires clear skies and clean horizon views to be visible. The best way to determine if you have a shot at seeing the selenelion is to check if your moonset and sunrise times are close together.

Here's NASA's handy viewing guide summary for catching the eclipse:

The entire October 08 eclipse is visible from the Pacific Ocean and regions immediately bordering it. The northwestern 1/3 of North America also witnesses all stages. Farther east, various phases occur after moonset. For instance, the Moon sets during totality from eastern Canada and the USA. Observers in South America also experience moonset during the early stages of the eclipse. All phases are visible from New Zealand and eastern 1/4 of Australia - the Moon rises during the early partial phases from Australia's west coast. Most of Japan and easternmost Asia catch the entire eclipse as well. Farther west in Asia, various stages of the eclipse occur before moonrise. None of the eclipse is visible from Europe, Africa, and the Middle East.

You can still enjoy eclipse watching, even if you're not in a prime viewing zone. The Slooh Community Observatory will be covering the event live online starting at 2 a.m. PT.