Lunar Eclipse 20/21 December 2010

Monday night / Tuesday morning 20/21 December 2010 will provide many of us a great opportunity to see a total lunar eclipse! This is when the moon passes through the shadow cast by the earth, which, like all direct shadows (of sunlight), are on the opposite side of the sun.

For us on the southwest coast of BC, the weather threatens to get in the way, but look out for it starting at 10:32pm PST Monday night. (This is 11:32pm MST and Tuesday morning at 12:32am CST or 1:32am EST.) At this time, the moon enters the earth's shadow.

From that time until 11:40pm, we should be able to see the curved shadow of the earth steadily working its way across the previously full moon. The best single view should be near the middle of that time period, say 11 to 11:15pm. If anyone thinks the earth is flat, this observation would be what I consider the single most immediate evidence of the approximate sphericity of the earth. (Question: Why do you think the earth is round?)from Wikimedia at

Then prepare yourself for a most ethereal experience, as from 11:40pm to 12:53am (PST) [that is 2:40am to 3:53am EST, etc.] the moon will be entirely in the earth’s shadow (technically, the “penumbra”).  (It later leaves the shadow entirely at 2:02am PST [5:02am EST, etc.]).

But that doesn’t mean it’s not visible! In fact, it will likely be a dim red due to all the collected and refracted sunrises and sunsets of the whole world. [This poetical expression is not original with me, and I unfortunately don’t know who wrote it first.]

It is interesting to note that we are able to predict this occurrence and all the specific times with great precision. This is due to the covenant faithfulness of God to his creation (see Genesis 8:22) and to our God-given abilities to answer our curiosity via careful study leading to the development of verisimilitudinous mathematical equations of astronomy.

So, enjoy and give God the glory! I’d be interested in hearing reports on the eclipse from all over, via your blog comments, or by E-mail. And the next astronomy course offered at TWU — taught by yours truly, and complete with telescopic observation — is in the Fall of 2011!

(I hope to say something about the next total solar eclipse as we get closer to its “scheduled” arrival date of 11 July 2011, visible only in the South Pacific and the southern half of South America. Time for a field trip!)



For more details and animations, see these websites:

Last updated Dec. 19th, 2010 at 5:45pm by Arnold Sikkema