| 词条 | September 2015 lunar eclipse | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
A total lunar eclipse took place between September 27 and 28, 2015. It was seen on Sunday evening, September 27, in the Americas; while in Europe, Africa, and the Middle East, it was seen in the early hours of Monday morning, September 28. It was the latter of two total lunar eclipses in 2015, and the final in a tetrad (four total lunar eclipses in series). Other eclipses in the tetrad are those of April 15, 2014, October 8, 2014, and April 4, 2015. The Moon appeared larger than normal, because the Moon was just 59 minutes past its closest approach to Earth in 2015 at mid-eclipse, sometimes called a supermoon. The Moon's apparent diameter was larger than 34' viewed straight overhead, just off the coast of northeast Brazil.[1][2] The total lunar eclipse was darker than expected, possibly due to ash left behind from eruptions of the Calbuco volcano in April 2015.[3] Background{{main|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.[4] 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 northern portion of the Moon was closest to the center of the shadow, making it darkest, and most red in appearance. VisibilityThe eclipse was visible over Europe, the Middle East, Africa, and America.
Timing
† The Moon was not visible during this part of the eclipse in this time zone.
GallerySupermoon{{Further|Supermoon}}This eclipsed moon appeared 12.9% larger in diameter than the April 2015 lunar eclipse, measured as 29.66' and 33.47' in diameter from earth's center, as compared in these simulated images. A supermoon is the coincidence of a full moon or a new moon with the closest approach the Moon makes to the Earth on its elliptical orbit, resulting in the largest apparent size of the lunar disk as seen from Earth. This was the last supermoon lunar eclipse until 31 January 2018. {{clear}}Related eclipsesThe eclipse was one of four lunar eclipses in a short-lived series at the descending 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, Earth's shadow will be about 11 degrees west in sequential events. {{Lunar eclipse set 2013-2016}}Half-Saros cycleA lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[6] This lunar eclipse is related to two annular solar eclipses of solar saros 144.
See also
References1. ^Sky and Telescope 2. ^Here’s the Scoop on Sunday’s Supermoon Eclipse, Bob King 3. ^{{Cite news|url=http://www.universetoday.com/122666/why-was-septembers-lunar-eclipse-so-dark/|title=Why Was September's Lunar Eclipse So Dark? - Universe Today|date=2015-10-05|work=Universe Today|access-date=2017-08-08|language=en-US}} 4. ^{{cite web|title=Visual Appearance of Lunar Eclipses|work=NASA|author=Fred Espenak|author2=Jean Meeus|last-author-amp=yes|url=http://eclipse.gsfc.nasa.gov/LEcat5/appearance.html|accessdate=April 13, 2014}} 5. ^{{cite web|last=Espenak|first=Fred|title=Lunar Eclipses for Beginners|url=http://www.mreclipse.com/Special/LEprimer.html|publisher=MrEclipse|accessdate=April 7, 2014}} 6. ^Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros External links{{Commons category|Lunar eclipse of 2015 September 28}}
4 : 21st-century lunar eclipses|2015 in science|Articles containing video clips|September 2015 events |
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