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May 20th, 2012 Annular Solar Eclipse

CAUTION! OBSERVING A SUN ECLIPSE IS DANGEROUS AND MAY CAUSE IRREVERSIBLE EYE DAMAGE, UP TO BLINDNESS, ANNULAR AND PARTIAL ECLIPSES INCLUDED! Observing a Sun eclipse necessitates DEDICATED SAFE TECHNIQUES!

That first solar eclipse in 2012 -and that year's first major astronomical event- is a annular eclipse occurring on May 20th, 2012 as it is stretching over northern Pacific, from China to the USA. A annular eclipse is occurring when the apparent diameter of the Moon is smaller than the one of the Sun, due to the general geometry of the eclipse. During a annular solar eclipse, a ring of Sun is still visible, surrounding the dark disk of the Moon, as it doesn't provide the observers with the more classical view of the Sun totally hidden and of the corona streaming away. During a annular eclipse, the 'umbra', the shadow yielded trough the eclipse is reaching the Earth nowhere, as it's, at the opposite, the 'antumbra' which does, a lesser kind of shadow. for more about the solar eclipses, theoretically, see our tutorial 'Sun Eclipses'

The eclipse's path is wide, at 150 to 185 miles, which is explained by the fact that Moon reached apogee one day earlier. That also yields that the annular ring is quite thick with Moon's apparent diameter only 94 percent that of the Sun. The annular eclipse is seen from Southern China down to western Texas in the USA, stretching all over the Pacific Ocean in-between. Japan is also concerned as Tokyo lies 6 miles North of the central line. When the eclipse will reach to southern Oregon and northern California, the Sun's altitude will be 20 degree only above the horizon then and decreasing from that when the eclipse keeps heading into US territory. At Albuquerque, NM, the Sun's altitude will have dropped to 5 degrees. A partial eclipse is seen on a wide area either side of the line of centrality, from the North Pole down to central Pacific and from central Siberia and eastern Indonesia to eastern Arctic Canadian Territories, and Baja California, Mexico. The closer the line of the eclipse, the more the indented Sun! The background of the eclipse is constituted by Taurus, the Bull as Jupiter and Mercury are close to the Sun and maybe a glimpse of those may be catched, as Venus is further away

a view of how the May 20th, 2012 Annular Solar Eclipse will look like from the neighbourhood of Tokyo, Japan. picture courtesy site 'Amateur Astronomy'

Eclipse's main data are the following (data as of November 2011, F. Espenak, NASA/GSFC). The Moon's apparent diameter will be of 29' 26.6", compared to the Sun's 31' 36.2". Greatest eclipse occurs at 23:52:47 UT over the open ocean, with a duration of annularity at that time of 5 minutes 46 seconds and the Sun 61 degree above the horizon. for more about how to observe a solar eclipse, see our tutorial 'Observing a Sun Eclipse':
- greatest eclipse: 23:52:46.6 UT
- eclipse magnitude (fraction of the Sun's diameter obscured by the Moon at greatest eclipse): 0.9439
- U1 to U4 (moments of first-last external-internal tangency of the antumbra with Earth's limb; practically these are the moments of the eclipse for the places where the eclipse is annular); in UT: U1 at 22:06:16.9, U2 at 22:11:46.7, U3 at 01:33:42.6, U4 at 01:39:10.9
- P1 to P4 (moments of first-last external-internal tangency of the penumbra with Earth's limb; practically these are the moments of the eclipse for the places where the eclipse is partial), in UT: P1 at 20:56:07, P4 at 02:49:21.5 (no P2 nor P3 times as the cone of the penumbra is not entirely contained upon Earth's disk)

see a .PDF map for the May 20th, 2012 Annular Solar Eclipse (a smaller .gif version is also available). map courtesy Fred Espenak - NASA/GSFC

. for more about this eclipse and for more about solar and lunar eclipses generally, you may see at Fred Espenak's NASA's eclipse website