April 2015 lunar eclipse

Total lunar eclipse
April 4, 2015

Los Angeles, California, 12:00 UTC
Ecliptic north up

The Moon passes right to left (west to east) through the Earth's shadow.
Gamma 0.4460
Duration (hr:mn:sc)
Totality 00:04:43
Partial 03:29:00
Penumbral 05:57:32
Contacts (UTC)
P1 9:01:27
U1 10:15:45
U2 11:57:54
Greatest 12:00:14
U3 12:02:37
U4 13:44:46
P4 14:58:58

A total lunar eclipse took place on 4 April 2015. It is the former of two total lunar eclipses in 2015, and the third in a tetrad (four total lunar eclipses in series). Other eclipses in the tetrad are those of 15 April 2014, 8 October 2014, and 28 September 2015.

Duration

Totality lasted only 4 minutes and 43 seconds,[1] making it the shortest lunar totality in almost five centuries since 17 October 1529 (which lasted 1 minute and 42 seconds). The next very short lunar totality will occur on 11 September 2155 (which will last 2 minutes and 36 seconds). This 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.

However, due to the oblateness of the Earth, this lunar eclipse may have actually been (barely) a partial eclipse.[2]

Visibility


View of earth from moon at greatest eclipse

The eclipse was visible across the Pacific, including all of Australia and New Zealand. It was visible near sunrise for North America, and after sunset for eastern Asia including India.

Gallery

Morning of April 4:

Evening of April 4:

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.[3]

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.

Timing

Local times of contacts
Timezone
adjustments from
UTC
+8h +11h +13h -10h -8h -7h -6h -5h -4h
AWST AEDT NZDT HADT AKDT PDT MDT CDT EDT
Event Evening April 4Morning April 4
P1 Penumbral begins 5:01 pm 8:01 pm 10:01 pm 12:01 am 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 1:16 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 2:58 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 3:00 am 4:00 am 5:00 am 6:00 am Set Set
U3 Total ends 8:03 pm 11:03 pm 1:03 am 3:03 am 4:03 am 5:03 am 6:03 am Set Set
U4 Partial ends 9:45 pm 12:45 am 2:45 am 4:45 am 5:45 am 6:45 am Set Set Set
P4 Penumbral ends 10:59 pm 1:59 am 3:59 am 5:59 am 6:59 am Set Set Set Set
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:[4]

P1 (First contact): Beginning of the penumbral eclipse. The Earth's penumbra touches the Moon's outer limb.
U1 (Second contact): Beginning of the partial eclipse. The Earth's umbra touches the Moon's outer limb.
U2 (Third contact): Beginning of the total eclipse. The Moon's surface is entirely within the Earth's umbra.
Greatest eclipse: The peak stage of the total eclipse. The Moon is at its closest to the center of the Earth's umbra.
U3 (Fourth contact): End of the total eclipse. The Moon's outer limb exits the Earth's umbra.
U4 (Fifth contact): End of the partial eclipse. The Earth's umbra leaves the Moon's surface.
P4 (Sixth contact): End of the penumbral eclipse. The Earth's penumbra no longer makes contact with the Moon.


Related eclipses

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[5] This lunar eclipse is related to two total solar eclipses of solar saros 139.

March 29, 2006 April 8, 2024

Lunar year series

The eclipse is the one of four lunar eclipses in a short-lived series at the ascending node of the moon's orbit.

The lunar year series repeats after 12 lunations, or 354 days (shifting back about 10 days in sequential years). Because of the date shift, the Earth's shadow will be about 11 degrees west in sequential events.

Lunar eclipse series sets from 2013–2016
Ascending node   Descending node
Saros Viewing
date
Type Saros Viewing
date
Type
112
2013 Apr 25
Partial
117
2013 Oct 18
Penumbral
122
2014 Apr 15
Total
127
2014 Oct 08
Total
132
2015 Apr 04
Total
137 2015 Sep 28
Total
142 2016 Mar 23
Penumbral
147 2016 Sep 16
Penumbral
Last set 2013 May 25 Last set 2012 Nov 28
Next set 2017 Feb 11 Next set 2016 Aug 18

Saros series

Lunar saros series 132, repeating every 18 years and 11 days, has a total of 71 lunar eclipse events including 12 total lunar eclipses.

Greatest First

The greatest eclipse of the series on 2123 Jun 9 will last 106 minutes.[6]
Penumbral Partial Total Central
1492 May 12
1636 Aug 16
2015 Apr 4
2069 May 6
Last
Central Total Partial Penumbral
2177 Jul 11
2213 Aug 2
2429 Dec 11
2754 Jun 26

There are 11 series events between 1901 and 2100, grouped into threes (called an exeligmos), each column with approximately the same viewing longitude on earth.

1901–2100
1907 Jan 29 1925 Feb 8 1943 Feb 20
1961 Mar 2 1979 Mar 13 1997 Mar 24
2015 Apr 4 2033 Apr 14 2051 Apr 26
2069 May 6 2087 May 17

See also

Notes

  1. http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2015Apr04T.pdf
  2. http://www.skyandtelescope.com/astronomy-news/observing-news/the-lunar-eclipse-wasnt-total-after-all-04062015/
  3. Fred Espenak and Jean Meeus. "Visual Appearance of Lunar Eclipses". NASA. Retrieved April 13, 2014.
  4. Clarke, Kevin. "On the nature of eclipses". Inconstant Moon. Cyclopedia Selenica. Retrieved 19 December 2010.
  5. Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
  6. Listing of Eclipses of series 132

External links

Wikimedia Commons has media related to Lunar eclipse of 2015 April 4.