Lunar Eclipse  (October 27, 2004)

Fig. 1.  The fully eclipsed Moon had a reddish orange color.  This photo was taken on 2004 October 27 at 23:06 EDT (local time) from the driveway of our house in Cockeysville, Maryland, around the time of the midpoint of the eclipse. Fig. 2.  A lunar eclipse happens when the Moon passes through Earth's direct shadow, called the penumbra. Fig. 3.  Time-lapse movie (1.9 Mb) of the entire lunar eclipse, demonstrating the passage of the Moon through Earth's shadow.  The motorized telescope mount compensates for Earth's rotation, so the Moon's motion shown here is due to its orbital motion around Earth.  While in Earth's shadow, the camera's exposure settings were increased in order to capture the appearance of the eclipsed Moon.  Portions of the eclipse were obscured by clouds.  Playing this movie requires web browser support of HTML5 video. Fig. 4.  A composite of three frames from the time-lapse movie in Fig. 3 showing the beginning, middle, and end of the eclipse.  This composite demonstrates the round outline of Earth's shadow in space and the Moon's appearance while in this shadow.

End of a Lucky Streak On average, total lunar eclipses happen approximately once in every 17 months.  But if you lived in the 17-month period between May 2003 and October 2004, you might have thought they happen much more frequently, because 4 total lunar eclipses occurred in this period.  Three of these eclipses were visible from most of North America, which included the driveway in front of our house in Cockeysville, Maryland.  As luck would have it, clouds obscured the first two eclipses, but we got lucky for the one in October 2004--the last total lunar eclipse for North America until 2007.    In the middle of the eclipse, the Moon appeared dark reddish orange (Fig. 1).  Although Earth blocks all direct sunlight from reaching the Moon during a lunar eclipse (Fig. 2), some sunlight is scattered by Earth's atmosphere and does reach the Moon.  This reddish light is the same as that you might see on Earth after a sunset.    Part or all of the Moon was in Earth's shadow for over 3.5 hours.  If you watch the whole event (Fig. 3), you can get an idea of the size and shape of Earth's shadow in space (Fig. 4).  More information about eclipses can be found on NASA's eclipse page.  The equipment we used to capture the event is outlined below. GPS location:  N 39 deg 28.277', W 76 deg 35.672', altitude 440 ft Camera:  Canon Digital Rebel SLR (6-megapixel resolution, 1.6X magnification compared to standard 35 mm format) with Sigma 80-200 mm telephoto zoom lens and 1.4X teleconverter (lens zoomed out to maximum) Exposure:  Ranged from 1/160 second at f/11 for beginning of eclipse to 25 seconds at f/4 during middle of eclipse, ISO 100 Telescope mount:  Camera mounted directly on Losmandy GM-8 equatorial mount with digital clock drive to compensate for Earth's rotation Computer:  Apple PowerBook G4 laptop with Canon's Remote Capture program set to acquire a photo every 60 seconds; total of 477 frames, some manually acquired Image processing:  Assembled frames into a movie, adjusted contrast, and added titles using Apple Final Cut Pro software ( back to home page)

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