Next Wednesday's Total Lunar Eclipse

The author took this image of a Total Lunar Eclipse on October 8, 2014, using an Olympus OMD EM5 and 200mm SMC lens

On this coming Wednesday (January 31, 2018) there will be a total eclipse of the moon that will be visible from many parts of the world. In Asia/Oceania the Eclipse occurs during the evening after sunset, while for North America it occurs in the morning before sunrise. This is a beautiful and eerie natural phenomena well worth taking some time out to view and photograph. To see whether you are in the eclipse zone refer to following diagram.

Adapted from Fred Espenak's diagram from https://eclipse.gsfc.nasa.gov

What is a Total Lunar Eclipse

Lunar Eclipse. Courtesy NASA

Simply put the moon moves into the earth's shadow, therefore blocking it from direct sunlight. If the earth had no atmosphere, the moon would become almost totally dark and would look like a starless hole in the sky. However, because of the earth's atmosphere some light is refracted around the earth which colors the moon a pretty Orange or Coppery hue. The coloration is due to the fact the blue light tends to be more scattered by the earth's atmosphere so exiting light tends to be redder. The Total Lunar Eclipse is not to be confused with a Total Solar Eclipse, which is where the moon is in front of the sun as seen from the earth.

Refracted sunlight is visible at the edge of the earth in image from space, this is what illuminates the moon during a total Lunar Eclipse. Courtesy: NASA

What to Expect

The whole process of the eclipse takes several hours, starting from a bright full moon a slight "bite" appears in the moon which is the point the earths shadow reaches the edge of the moon. It takes about an hour for the shadow to completely engulf the moon, all the time the brightness of the moon subsides allowing the sky to darken and more stars to become visible. Once the shadow is fully across the moon takes on a beautifully coppery hue, although there are often subtle variations of color across the moon. The moon darkens a little as it reaches mid eclipse, before the whole process happens in reverse. All told totality for this eclipse is a bit over an hour.

Here a times for the start and end of the eclipse for various locations on Wednesday, Jan 31, 2018.

Time Zone	Example Cities	Start Time	End Time
GMT+8	Shanghai,Hong Kong	7:48pm	11:11pm
GMT+9	Singapore,Toyko	8:48pm	12:11am
GMT+10	Brisbane	9:48pm	1:11am
GMT+11	Sydney,Melbourne	10:48pm	2:11am
GMT-10	Honolulu	12:48am	6:11am
GMT-8	Los Angeles	2:48am	Moon sets

A good site for more specific predictions can be found here https://www.timeanddate.com/eclipse/

References

1. Fred Espenak. LUNAR ECLIPSES: 2011 - 2020. https://eclipse.gsfc.nasa.gov/LEdecade/LEdecade2011.html