One of the astronomical highlights of 2014 graces the night sky this coming Monday evening into Tuesday morning on the night of April 14/15, when the Moon meets the Earth’s shadow for a total lunar eclipse.
This is the first total lunar eclipse to occur since Dec 10, 2011. And the good news is all of North and South America, including Canada will see the full ine hour and 18 minutes of totality, and three more total lunar eclipses are in store through the end of 2015.
Field guide to the total lunar eclipse of April 14 – 15, 2014 from Michael Zeiler on Vimeo.
Such an occurrence of four total lunar eclipses in back-to-back years is what’s known as a “tetrad” and they’re far from rare, with eight such groupings occurring in this century. There’s some minor hoopla swirling around the web that the ‘Blood Moon” tetrad of 2014-2015 has some special portent as they fall on Passover and Sukkot. But have no fear; this latest “End of the World of the Week” will soon harmlessly come to pass.
What you can expect, however, is a fine celestial show. Unlike solar eclipses, you can simply view a lunar eclipse using nothing but your eyes. No special glasses or filtered telescopes are needed. The penumbral phases tend to be faint, but you’ll definitely notice something is up when the Moon begins to enter the dark umbra of the Earth’s shadow at 5:58 Universal Time (UT)/1:58 AM EDT on the morning of April 15. This “bite” off of the Moon’s eastern edge will continue to grow until it is fully immersed in the Earth’s shadow at 7:07 UT/3:07 AM EDT.
This is known as totality, and it’s also the time that’ll you’ll see a hallmark of a total lunar eclipse. Does the eclipsed Moon appear reddish to you? What you’re seeing is the sunlight of a thousand sunsets worldwide, streaming through the Earth’s atmosphere into the shadow. This color can vary considerably from eclipse to eclipse, causing it to appear anywhere from a dark tea-stained color to a bright cherry red. This variation is due to the amount of dust currently in the Earth’s atmosphere, and is measured on what is known as the Danjon scale.
The reverse phases of a lunar eclipse mirror the beginning, with the Moon sliding back out of the Earth’s shadow. See two bright “stars” nearby? Those are actually the ruddy planet Mars and the blue-white star Spica, the brightest star in the constellation Virgo. Mars is actually at its closest approach to the Earth for 2014 on the night of the eclipse at just under 96 million kilometres distant.
Photographing an eclipse with a DSLR is easy, though you’ll need a minimum focal length lens of 200mm or greater for the Moon to appear much larger than a silvery dot. Practice on the waning gibbous Moon on the evenings before the eclipse to get the combination of shutter speed and ISO just right, and remember that you’ll have to slow the exposure down to about the 1 to 6 second range during the darker phase of totality.
Areas from Quebec eastward to the Canadian Maritimes will see the final partial phases of the eclipse low to the western horizon, a good chance to get some foreground objects into the shot.