Saturday May 5th will be the largest and brightest full Moon of the year. The spectacular “supermoon” will shine its brightest at 11:35 p.m., when the full Moon’s peak coincides with its closest approach to the Earth’s orbit— a mere 221,802 miles from earth.
David Morrison, NLSI’s Senior Scientist, says “supermoon” is not an astronomical term and a supermoon has no effect on Earth. Every month, as the Moon circles the Earth in its elongated orbit, its distance from the Earth varies. At perigee (the point in the Moon’s orbit which is closest to the Earth), it is 14% closer than at apogee (the point in the Moon’s orbit which is furthest from Earth), so it may appear 14% larger, but this change is so small that it is hardly noticeable. If you miss it, the Moon will be very nearly as close at the next full moon, and very nearly as close as it was at the last full Moon.
What’s even more interesting is that two weeks after the “supermoon” on May 5th, the moon will be at apogee as it lines up in front of the sun for an amazing annular eclipse on May 20th. An annular eclipse occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the outline of the Moon.
This timelapse shows an annular eclipse as seen by JAXA’s Hinode satellite on Jan. 4, 2011. An annular eclipse occurs when the Moon, slightly more distant from Earth than on average, moves directly between Earth and the sun, thus appearing slightly smaller to observers’ eyes; the effect is a bright ring, or annulus of sunlight, around the silhouette of the Moon.
For more information, including a map showing the path of the May 20th 2012 Annular Eclipse and a decadal table of solar eclipses, visit NASA’s Eclipse Website.
Posted by: Soderman/NLSI Staff