Monday, February 9, 2009

Penumbral Lunar Eclipse

Penumbral Lunar Eclipse on February 9, 2009

A penumbral lunar eclipse, which will occur on February 9, 2009, will be the first lunar eclipse of the year. People can experience the eclipse in areas such as Alaska, Australia, eastern Asia, Hawaii, and New Zealand. This eclipse follows an annular solar eclipse that was marked as 2009’s first eclipse.


This illustration shows the penumbral lunar eclipse on February 9, 2009. It is fairly close to scale and illustrates how the moon passes through the penumbral portion of the earth’s shadow.

Will the Eclipse be Visible?

Many penumbral eclipses have few observable effects but the February 9 lunar eclipse will carry the moon far enough into the light gray shadow to produce a dimming of the northern lunar limb. According to NASA, this event is the deepest penumbral eclipse in 2009, with a penumbral magnitude of 0.899. It will be visible to the naked eye as dusky shading in the northern half of the moon.

When to Watch for the Eclipse?

The eclipse’s start and end are not visible to the human eye. No shading can be detected until about two-thirds of the moon's disk is immersed in the penumbra. Therefore the eclipse’s estimated visibility period is from about 14:00 to 15:20 Coordinated Universal Time (UTC).

The times of the eclipse’s major phases are:

  • Penumbral eclipse starts at 12:38:46 UTC.
  • Greatest eclipse occurs at 14:38:15 UTC.
  • Penumbral eclipse ends at 16:37:40 UTC.

People who wish to see the eclipse may need to consider atmospheric conditions and their visual acuity. The eclipse will also be visible only in some parts of the world.

Where Will the Eclipse be Visible?

The eastern parts of Canada and the United States (USA) will miss the eclipse because it begins after moonset. Observers in the western parts of Canada and the USA will have the best views with moonset occurring sometime after the mid-eclipse. To catch the entire event, one must be in places such as Alaska, Australia, eastern Asia, Hawaii or New Zealand.

Brief Explanation of the Penumbral Lunar Eclipse

A penumbra refers to a partially shaded outer region of a shadow that an object casts. A penumbral eclipse occurs when the moon passes through the faint penumbral portion of the earth’s shadow. The lunar surface is not completely shadowed by the earth’s umbra (darkest part of a shadow). Instead, observers see only the slightest dimming near the lunar limb closest to the umbra. The eclipse may be undetectable unless at least half of the moon enters the penumbra.

Eclipses in 2009

The penumbral lunar eclipse on February 9, 2009, is not the only eclipse to occur during the year. The list of eclipses for 2009 includes:

  • An annular solar eclipse on January 26.
  • A penumbral lunar eclipse on February 9.
  • A penumbral lunar eclipse on July 7.
  • A total solar eclipse on July 22.
  • A penumbral lunar eclipse on August 6.
  • A partial lunar eclipse on December 31.

Timeanddate.com will provide information about the other eclipses closer to the time of their occurrence and as more details about them come on hand.

Note: Eclipse information courtesy of Fred Espenak, NASA/Goddard Space Flight Center, and P. Harrington, author of Eclipse! The What, Where, When, Why & How Guide to Watching Solar and Lunar Eclipses.

SOURCES FROM : http://www.timeanddate.com/eclipse/lunar-eclipse-february-2009.html

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