If you missed the total eclipse of the moon in April, you might have another chance: Wednesday morning is the second of four lunar eclipses this year and next — a rare occurrence known as a tetrad. According to CBS Los Angeles, there are only fifty-five tetrads recorded since 1 AD.
As in April, the eclipse this week will be another "Blood Moon" because, as Space.com explains, the reflected light off the lunar surface first passed through the Earth's atmosphere, where the sun's rays are scattered, stripping out the other colors in the spectrum.
KPCC science reporter Sanden Totten offers a visual explanation:
Interested skywatchers should attempt to see the total eclipse of the moon and the rising sun simultaneously. The little-used name for this effect is called a 'selenelion,' a phenomenon that celestial geometry says cannot happen.
And indeed, during a lunar eclipse, the sun and moon are exactly 180 degrees apart in the sky. In a perfect alignment like this (called a 'syzygy'), such an observation would seem impossible. But thanks to Earth's atmosphere, the images of both the sun and moon are apparently lifted above the horizon by atmospheric refraction. This allows people on Earth to see the sun for several extra minutes before it actually has risen and the moon for several extra minutes after it has actually set.
Where and when to watch
While the eclipse will be visible from all of North America, "If you're in the central or western parts of the U.S. and Canada, you'll see the total eclipse high in a dark sky well before sunrise. Easterners will find dawn brightening and the Moon sinking low in the west while the eclipse is in progress — offering particularly interesting photo opportunities. Viewers in Australia and eastern Asia get to view this event on the evening of October 8th local date," according to Sky & Telescope magazine.
For Inland Empire residents, there's a public telescope observation hosted by the University of California, Riverside from 2 a.m. to 4 a.m. Two telescopes will be available at the bell tower on campus.
Below is a time table that tells you exactly when to look up in Los Angeles. The data is from a handy calculator of the U.S. Naval Observatory.
|Event||Time (Pacific Daylight Time)|
|Moonrise||2014 Oct 07 18:08 p.m.|
|Moon enters penumbra||2014 Oct 08 01:14.1 a.m.|
|Moon enters umbra||2014 Oct 08 02:14.5 a.m.|
|Moon enters totality||2014 Oct 08 03:24.6 a.m.|
|Middle of eclipse||2014 Oct 08 03:54.6 a.m.|
|Moon leaves totality||2014 Oct 08 04:24.5 a.m.|
|Moon leaves umbra||2014 Oct 08 05:34.7 a.m.|
|Moon leaves penumbra||2014 Oct 08 06:35.2 a.m.|
|Moonset||2014 Oct 08 07:05 a.m.|
The image below explains the progression and types of lunar eclipse.
(The different types of lunar eclipse are defined by the path taken by the moon as it passes through the earth's shadow. "Umbra" simply refers to the darkest part or interior of a shadow, while "penumbra" refers to the more lightly shaded outer regions of a shadow. Credit: Wikimedia Commons/Creative Commons License)
If you're stuck under cloudy skies, Sky & Telescope gives some other options to watch the Blood Moon online:
- Griffith Observatory plans a 4½-hour-long webcast beginning on October 8th at 1:15 a.m. PDT.
- Gianluca Masi has assembled an international team of photographers for his Virtual Telescope Project webcast at 3:00 a.m. PDT.
This story has been updated.