A Very Partial Eclipse, 25 April 20:08:36 UT

Apparitions like the Partial Lunar Eclipse April 25, 2013 demonstrate the miraculous improbability of lunar and solar eclipses on Earth actually are, because an exceptionally sensitive light meter will be needed to detect any apparition at all [NASA/GSFC].

They don't come more partial. In line of sight from Earth the Partial Lunar Eclipse of April 25 may serve to demonstrate the ephemeral depth of the umbra of Earth's long shadow.

As carefully mapped out in Espenak's schematic from Goddard Space Flight Center (PDF and HERE) The penumbral phase first contact (P1) occurs at 18:03:38 UT and terminates (P4) at 22:11:26 UT, totalling 4 hours, 7 minutes and 47 seconds.

The Umbral first contact (U1) occurs at 19:54:08 UT and ends (U4) at 20:21:02 UT, darkening the Moon's far north 26 minutes, 55 seconds. Maximum occurs at 20:08:36 UT.

The capstone of the International Year of Astronomy 2009, the Blue Moon Partial Eclipse New Years Eve, 31 December 2009 captured by Jean Paul Roux and featured as NASA's Astronomy Picture of the Day, 2 January 2011.

The partial eclipse of the Moon from lunar orbit

The view from low lunar orbit. The partial eclipse of the Moon June 4, 2012 may not have seemed very dramatic, for those living along the Pacific Rim fortunate enough to see it, but this line up of nodes and crossings became a solar eclipse when viewed from the Moon using Martin Schweiger's priceless Orbiter Simulator (2010 P1) program. On the left Venus closes in for it's June 5 transit. The angle above was weaved from a perspective 70 kilometers over the Moon's western limb timed at 0946 UT, June 4, 2012 [Orbiter 2010 P1/Martin Schweiger].

Sequential HDTV stills capture a total eclipse of the Sun (a dramatic 2009 total eclipse of the Moon for those of us still on Earth), from Japan's lunar orbiter SELENE-1 (Kaguya) [JAXA/NHK/SELENE].

Blue Moon Eclipse

The International Year of Astronomy 2009 ended with a Blue Moon and a partial lunar eclipse, as the second Full Moon of December grazed the Earth's shadow on December 31st. The New Year's Eve Blue Moon eclipse was visible throughout Europe, Asia, Africa and parts of Alaska, captured in this two exposure composite in cloudy skies over Saint Bonnet de Mure, France. Playing across the Moon's southern reaches, the edge of Earth's umbra, or dark central shadow, appears on the right side along with the prominent ray crater Tycho. At maximum eclipse, the umbra covered only about 8 percent of the diameter of the lunar disk. Read More

Penumbral Lunar Eclipse Imaged

At last Full Moon, August 5, (a last iteration of the "mystical" Triple-Eclipse which had serious Astrologers, particularly in India, concerned, as detailed HERE) the Moon's southern hemisphere slid through the northmost edge of Earth's refracted "outer shadow. As the most partial of lunar eclipses are, this one was virtually impossible to detect buy earthbound observers.

Or, as John Walker wrote at Fourmilab's blog "None Dare Call it Reason," or Fourmilog, "the most subtle phenomena in naked eye astronomy is a penumbral lunar eclipse: the Moon does not pass into the region of the Earth's shadow where the Sun is entirely obscured by the Earth, and consequently, although sunlight on some or all of the Moon is partly blocked by the Earth, the visual effect is very difficult to perceive, especially with the logarithmic transfer function of human vision and its inability to make absolute intensity comparisons of events.

"Fortunately, here in the 21st century, although we don't (yet) have ATOMIC SPACE CARS, we do have magnificently linear digital sensors in our cameras, so it seemed entirely plausible to me that I'd be able to capture the ever so slight shading of the Earth's fuzzy shadow on the Moon during the penumbral lunar eclipse of August 6th, 2009.

"So, I set up my Nikon D300 camera and Nikkor 500 mm catadioptric “mirror lens” (you can see them here another context) about an hour before the eclipse was to begin to allow the optics to equilibrate to the ambient temperature. Then, just before the start of the eclipse, I shot a number of photos of the Moon with various exposure times..."

The Result is excellent, though Mr. Walker almost apologizes for not having corrected for "an apparent rotation," what he has captured is the Moon's fast-moving librational wobble.

It's worth a look, and he has allowed access to a large version by clicking on the version posted to the blog.