April 2015 lunar eclipse

April 2015 lunar eclipse
Total eclipse
Totality as viewed from Los Angeles, California, 12:00 UTC
DateApril 4, 2015
Gamma0.4460
Magnitude1.0019
Saros cycle132 (30 of 71)
Totality4 minutes, 43 seconds
Partiality209 minutes, 1 second
Penumbral357 minutes, 31 seconds
Contacts (UTC)
P109:01:27
U110:15:45
U211:57:54
Greatest12:00:15
U312:02:37
U413:44:46
P414:58:58

A total lunar eclipse occurred at the Moon’s ascending node of orbit on Saturday, April 4, 2015,[1] with an umbral magnitude of 1.0019. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 3.1 days after apogee (on April 1, 2015, at 9:00 UTC), the Moon's apparent diameter was smaller.[2]

This lunar eclipse is the third of a tetrad, with four total lunar eclipses in series, the others being on April 15, 2014; October 8, 2014; and September 28, 2015.

This is the 30th member of Lunar Saros 132, and the first total eclipse of the series. The previous event was the March 1997 lunar eclipse, being slightly partial.

Duration

Totality lasted only 4 minutes and 43 seconds,[3] making it the shortest lunar totality in almost five centuries since October 17, 1529 (which lasted 1 minute and 42 seconds). It was claimed by some that due to the oblateness of the Earth, it may have actually just been a partial eclipse.[4] It was the sixth total lunar eclipse out of nine with totality under 5 minutes in a five millennium period between 2,000 BC and 3,000 AD. The eclipsed moon was 12.9% smaller in apparent diameter than the supermoon September 2015 lunar eclipse, measured as 29.66' and 33.47' in diameter from the center of the Earth. It occurred 3 days past apogee at 29.42'.

Background

Main article: Lunar eclipse

A lunar eclipse occurs when the Moon passes within Earth's umbra (shadow). As the eclipse begins, Earth's shadow first darkens the Moon slightly. Then, the shadow begins to "cover" part of the Moon, turning it a dark red-brown color (typically - the color can vary based on atmospheric conditions). The Moon appears to be reddish because of Rayleigh scattering (the same effect that causes sunsets to appear reddish) and the refraction of that light by Earth's atmosphere into its umbra.[5]

The following simulation shows the approximate appearance of the Moon passing through Earth's shadow. The Moon's brightness is exaggerated within the umbral shadow. The southern portion of the Moon will be closest to the center of the shadow, making it darkest, and most red in appearance.

Visibility

The eclipse was completely visible over northeast Asia, eastern Australia, the Pacific Ocean, and western North America, seen rising over Asia and western Australia and setting over North and South America.[6]


Visibility map

Timing

Local times of contacts
Time Zone
adjustments from
UTC 		+8h +11h +13h -10h -8h -7h -6h -5h -4h
AWST AEDT NZDT HST AKDT PDT MDT CDT EDT
Event Evening April 4 Morning April 4
P1 Penumbral begins N/A† 8:01 pm 10:01 pm 11:01 pm 1:01 am 2:01 am 3:01 am 4:01 am 5:01 am
U1 Partial begins 6:16 pm 9:16 pm 11:16 pm 12:16 am 2:16 am 3:16 am 4:16 am 5:16 am 6:16 am
U2 Total begins 7:58 pm 10:58 pm 12:58 am 1:58 am 3:58 am 4:58 am 5:58 am 6:58 am Set
Greatest eclipse 8:00 pm 11:00 pm 1:00 am 2:00 am 4:00 am 5:00 am 6:00 am 7:00 am Set
U3 Total ends 8:03 pm 11:03 pm 1:03 am 2:03 am 4:03 am 5:03 am 6:03 am Set Set
U4 Partial ends 9:45 pm 12:45 am 2:45 am 3:45 am 5:45 am Set Set Set Set
P4 Penumbral ends 10:59 pm 1:59 am 3:59 am 3:59 am 5:59 am Set Set Set Set

† The Moon was not visible during this part of the eclipse in this time zone.

Contact points relative to the Earth's umbral and penumbral shadows, here with the Moon near its descending node.
The timing of total lunar eclipses are determined by its contacts:[7]
  • P1 (First contact): Beginning of the penumbral eclipse. Earth's penumbra touches the Moon's outer limb.
  • U1 (Second contact): Beginning of the partial eclipse. Earth's umbra touches the Moon's outer limb.
  • U2 (Third contact): Beginning of the total eclipse. The Moon's surface is entirely within Earth's umbra.
  • Greatest eclipse: The peak stage of the total eclipse. The Moon is at its closest to the center of Earth's umbra.
  • U3 (Fourth contact): End of the total eclipse. The Moon's outer limb exits Earth's umbra.
  • U4 (Fifth contact): End of the partial eclipse. Earth's umbra leaves the Moon's surface.
  • P4 (Sixth contact): End of the penumbral eclipse. Earth's penumbra no longer makes contact with the Moon.

Progression from Bali, Indonesia

Time-lapsed image from Taiwan
Sequence from Fox Observatory in Sunrise, Florida

Sequence from Melbourne, Florida
Progression from St. Louis, Missouri

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[8]

April 4, 2015 Lunar Eclipse Parameters
Parameter Value
Penumbral Magnitude 2.08024
Umbral Magnitude 1.00191
Gamma 0.44599
Sun Right Ascension 00h53m01.2s
Sun Declination +05°40'32.8"
Sun Semi-Diameter 15'59.6"
Sun Equatorial Horizontal Parallax 08.8"
Moon Right Ascension 12h53m29.7s
Moon Declination -05°17'20.2"
Moon Semi-Diameter 14'49.9"
Moon Equatorial Horizontal Parallax 0°54'25.9"
ΔT 67.7 s

Eclipse season

See also: Eclipse cycle

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.

Eclipse season of March–April 2015
March 20
Descending node (new moon)
 April 4
Ascending node (full moon)
Total solar eclipse
Solar Saros 120		 Total lunar eclipse
Lunar Saros 132

Eclipses in 2015

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 132

Inex

Triad

Lunar eclipses of 2013–2016

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[9]

The penumbral lunar eclipse on May 25, 2013 occurs in the previous lunar year eclipse set, and the penumbral lunar eclipse on August 18, 2016 occurs in the next lunar year eclipse set.

Lunar eclipse series sets from 2013 to 2016
Ascending node   Descending node
Saros Date
Viewing 		Type
Chart 		Gamma Saros Date
Viewing 		Type
Chart 		Gamma
112
 2013 Apr 25
 Partial
 −1.0121 117
 2013 Oct 18
 Penumbral
 1.1508
122
 2014 Apr 15
 Total
 −0.3017 127
 2014 Oct 08
 Total
 0.3827
132
 2015 Apr 04
 Total
 0.4460 137
 2015 Sep 28
 Total
 −0.3296
142 2016 Mar 23
 Penumbral
 1.1592 147
 2016 Sep 16
 Penumbral
 −1.0549

Saros 132

This eclipse is a part of Saros series 132, repeating every 18 years, 11 days, and containing 71 events. The series started with a penumbral lunar eclipse on May 12, 1492. It contains partial eclipses from August 16, 1636 through March 24, 1997; total eclipses from April 4, 2015 through August 2, 2213; and a second set of partial eclipses from August 13, 2231 through November 30, 2411. The series ends at member 71 as a penumbral eclipse on June 26, 2754.

The longest duration of totality will be produced by member 36 at 106 minutes, 6 seconds on June 9, 2123. All eclipses in this series occur at the Moon’s ascending node of orbit.[10]

Greatest First

The greatest eclipse of the series will occur on 2123 Jun 09, lasting 106 minutes, 6 seconds.[11] 		Penumbral Partial Total Central
1492 May 12
 1636 Aug 16
 2015 Apr 04
 2069 May 06
Last
Central Total Partial Penumbral
2177 Jul 11
 2213 Aug 02
 2411 Nov 30
 2754 Jun 26

Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[12] This lunar eclipse is related to two total solar eclipses of solar saros 139.

March 29, 2006 April 8, 2024

See also

Notes

  1. ^ "April 4, 2015 Total Lunar Eclipse (Blood Moon)". timeanddate. Retrieved 16 November 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 16 November 2024.
  3. ^ Espenak, Fred. "Total Lunar Eclipse of 2015 Apr 04" (PDF). NASA's GSFC.
  4. ^ "The Lunar Eclipse Wasn't Total After All?!". Sky & Telescope. 6 April 2015.
  5. ^ Fred Espenak and Jean Meeus. "Visual Appearance of Lunar Eclipses". NASA. Retrieved 13 April 2014.
  6. ^ "Total Lunar Eclipse of 2015 Apr 04" (PDF). NASA. Retrieved 16 November 2024.
  7. ^ Clarke, Kevin. "On the nature of eclipses". Inconstant Moon. Cyclopedia Selenica. Retrieved 19 December 2010.
  8. ^ "Total Lunar Eclipse of 2015 Apr 04". EclipseWise.com. Retrieved 16 November 2024.
  9. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  10. ^ "NASA - Catalog of Lunar Eclipses of Saros 132". eclipse.gsfc.nasa.gov.
  11. ^ Listing of Eclipses of series 132
  12. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
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