Penumbral Lunar Eclipse 18 August 2016 | |
---|---|
The Moon barely clipped the northern penumbral shadow of the Earth. | |
Series (and member) | 109 (72 of 72) |
Gamma | 1.559 |
Magnitude | -0.9925 |
Duration (hr:mn:sc) | |
Penumbral | 33:36 |
Contacts (UTC) | |
P1 | 9:25:36 UTC |
Greatest | 9:42:24 |
P4 | 9:59:12 |
A penumbral lunar eclipse took place on Thursday, 18 August 2016. It was the second of three lunar eclipses in 2016. This was 3.7 days before the Moon reached perigee. There are multiple ways to determine the boundaries of Earth's shadow, so this was a miss according to some sources. The HM National Almanac Office's online canon of eclipses lists this event as the last eclipse on Saros Series 109, [1] while NASA lists August 8, 1998 as the last eclipse of the series, and has this event missing the shadow. [2]
The Earth's penumbral shadow is larger than would be expected from simple geometry, a phenomenon first observed by Philippe de La Hire in 1707. The precise amount of enlargement varies over time for reasons which are not fully understood, but likely involve the amount of dust in certain layers of the Earth's atmosphere. [3] Various eclipse almanacs have used different assumptions about the magnitude of this effect, resulting in disagreement about the predicted duration of lunar eclipses or, in the case of penumbral eclipses of very short duration, whether the eclipse will occur at all. [4]
In 1989, NASA published a lunar eclipse almanac that predicted a short penumbral lunar eclipse to occur on 18 August 2016. However, the French almanac Connaissance des Temps used more conservative assumptions about the size of the Earth's shadow and did not predict an eclipse to occur at all. [4] The Bureau des Longitudes in France continued to refine their lunar eclipse models; NASA's 2009 edition of its lunar eclipse almanac was based on their values, [5] which effectively reclassified nine eclipses between 1801 and 2300 as non-events, including the one in August 2016. [lower-alpha 1] [6]
Some resources, including the HM Nautical Almanac Office's online canon of eclipses, continued to list the 18 August 2016 event. Despite not appearing in NASA's printed lists of eclipses since the 2009 revision, AccuWeather reported the upcoming eclipse and projected this was the final member of Lunar Saros 109. [7]
This eclipse grazed the northern boundary of the Earth's penumbral shadow. The event lasted 33 minutes and 36 seconds, beginning at 9:25 UTC and ending at 9:59. This produced a maximum penumbral magnitude of 0.0166. [8] Eclipses of such small magnitudes are visually imperceptible; a penumbral magnitude of approximately 0.6 is required for even skilled observers to detect. [9]
Two other penumbral lunar eclipses occurred in 2016, they were on 23 March and 16 September.
Lunar eclipse series sets from 2016–2020 | ||||||||
---|---|---|---|---|---|---|---|---|
Descending node | Ascending node | |||||||
Saros | Date | Type Viewing | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
109 | 2016 Aug 18 | Penumbral | 1.56406 | 114 | 2017 Feb 11 | Penumbral | −1.02548 | |
119 | 2017 Aug 07 | Partial | 0.86690 | 124 | 2018 Jan 31 | Total | −0.30143 | |
129 | 2018 Jul 27 | Total | 0.11681 | 134 | 2019 Jan 21 | Total | 0.36842 | |
139 | 2019 Jul 16 | Partial | −0.64300 | 144 | 2020 Jan 10 | Penumbral | 1.07270 | |
149 | 2020 Jul 05 | Penumbral | −1.36387 | |||||
Last set | 2016 Sep 16 | Last set | 2016 Mar 23 | |||||
Next set | 2020 Jun 05 | Next set | 2020 Nov 30 |
According to some sources, this was the last lunar eclipse of Saros cycle 109, and was eclipse 72 in that series. [8] There are many ways to determine the boundaries of Earth's shadow. One model was revised and this eclipse was classified a non-event by that model. Some eclipse sites decided to follow those calculations which meant Saros 109 now includes 71 events, with the last occurring on 8 August 1998. [2]
A penumbral lunar eclipse took place on 7 July 2009, the second of four lunar eclipses in 2009. This eclipse entered only the southernmost tip of the penumbral shadow and thus was predicted to be very difficult to observe visually. This lunar eclipse was the predecessor of the solar eclipse of 22 July 2009.
A total lunar eclipse will take place on July 7, 2047. It will last 1 hour 40 minutes and 49 seconds and will plunge the full Moon into deep darkness, as it passes right through the centre of the Earth's umbral shadow. While the visual effect of a total eclipse is variable, the Moon may be stained a deep orange or red colour at maximum eclipse. This will be a great spectacle for everyone who sees it. The partial eclipse will last for 3 hours and 39 minutes in total.
A penumbral lunar eclipse took place on Thursday, March 3, 1988, the first of two lunar eclipses in 1988, the second being on August 27, 1988. Earlier sources compute this as a 0.3% partial eclipse lasting under 14 minutes, and newest calculations list it as a penumbral eclipse that never enters the umbral shadow. In a rare total penumbral eclipse, the entire Moon was partially shaded by the Earth, and the shading across the Moon should have been quite visible at maximum eclipse. The penumbral phase lasted for 4 hours, 53 minutes and 50.6 seconds in all, though for most of it, the eclipse was extremely difficult or impossible to see. The Moon was 2.2 days after apogee, making it 6.1% smaller than average.
A penumbral lunar eclipse took place on Tuesday, May 15, 1984, the first of three lunar eclipses in 1984. This was a deep penumbral eclipse, with the southern limb of the Moon close to the Earth's shadow.
A penumbral lunar eclipse took place on Tuesday, January 20, 1981, the first of two lunar eclipses in 1981. In a rare total penumbral eclipse, the entire Moon was partially shaded by the Earth, and the shading across the Moon should have been quite visible at maximum eclipse. The penumbral phase lasted for 4 hours and 24 minutes in all, though for most of it, the eclipse was extremely difficult or impossible to see. The moon's apparent diameter was larger because the eclipse occurred 5.2 days after perigee.
A penumbral lunar eclipse took place on Sunday, July 27, 1980, the second of three penumbral lunar eclipses in 1980. This very subtle penumbral eclipse was essentially invisible to the naked eye; though it lasted 2 hours, 17 minutes and 36.3 seconds, just 25.354% of the Moon's disc was in partial shadow. The moon passed in the northern edge of the Earth's penumbral shadow, and was the 70th lunar eclipse of Saros cycle 109.
A penumbral lunar eclipse occurred on Friday, 5 May 2023, the first of two lunar eclipses in 2023. The moon's apparent diameter was 0.1% larger than average because it occurred 5.5 days before perigee. This was the deepest penumbral eclipse since February 2017 and until September 2042.
A penumbral lunar eclipse will take place on 18 July 2027. The Moon will barely clip the edge of the Earth's penumbral shadow, and the eclipse will be impossible to see in practice. The event is listed as a miss by some sources.
A penumbral lunar eclipse will take place on May 7, 2031.
A penumbral lunar eclipse took place on Wednesday, February 21, 1951. This was 6.4 days after the Moon reached apogee.
A total penumbral lunar eclipse is a lunar eclipse that occurs when the Moon becomes completely immersed in the penumbral cone of the Earth without touching the umbra.
A total lunar eclipse will take place on January 1, 2048. It will be the first recorded lunar eclipse to be visible on New Year's Day for nearly all of Earth's timezones. The next such eclipse will occur in 2094.
A penumbral lunar eclipse will take place on March 3, 2045.
A total lunar eclipse will take place on September 19, 2043.
A total lunar eclipse will take place on September 7, 2044. It will be the first total eclipse in Lunar Saros 138.
A total lunar eclipse will take place on March 13, 2044.
A penumbral lunar eclipse will take place on December 20, 2048.
A penumbral lunar eclipse will take place on May 17, 2049.
A total lunar eclipse will take place on April 26, 2051.
A total lunar eclipse will take place on October 30, 2050.