© John Buonomo, North Billerica, MA.

Total lunar eclipse

Dominic Ford, Editor
From the Eclipses feed

A simulation of how the eclipse will appear from Ashburn.
Time:       Altitude: °      Azimuth: °
The outer grey circle is the Earth's penumbra, and the inner black circle is the umbra. Any part of the Moon which passes within the black circle will be unilluminated, while any part within the grey circle will appear less bright than usual.



The Moon will pass through the Earth's shadow between 21:22 and 00:56 EDT, creating a total lunar eclipse. The eclipse will be visible any location where the Moon is above the horizon at the time, including from Africa, the Americas, Europe and Western Asia.

It will be visible from Ashburn in the south-eastern sky. The Moon will lie 29° above the horizon at the midpoint of the eclipse.

The total eclipse will last from 22:21 until 23:56. The Moon will be partially eclipsed between 21:22 and 00:56 (all times given in Ashburn time).

Eclipses of the Moon are easy to watch with the unaided eye. A modest pair of binoculars will give a superb view of the Moon's surface, but are not required. Unlike solar eclipses, lunar eclipses are entirely safe to look at without the need to look through any kind of filter.

They occur whenever the Earth passes between the Moon and Sun, such that it obscures the Sun's light and casts a shadow onto the Moon's surface. The circular shadow cast by the Earth appears as a bite taken out of the Moon during its partial phases.

When the Moon's disk lies entirely in shadow, it often takes on a spectacular reddy-brown color, as some of the Sun's red light is bent around the edge of the Earth's globe by its atmosphere.

Sequence of events

The eclipse will begin at 20:25, when the Moon first enters a region of the Earth's shadow called the penumbra. In this outer part of the Earth's shadow, an observer on the Moon would see the Sun partially obscuring the Sun's disk, but not completely covering it. As a result the Moon's brightness will begin to dim, as it is less strongly illuminated by the Sun, but it remains illuminated.

At 21:22, the edge of the Moon's disk will enter the Earth's umbra. This is the region of space in which an observer on the Moon's surface would see the Earth completely obscuring the whole of the Sun's disk, and would find themselves suddenly thrust into darkness.

As an increasing fraction of the Moon's face creeps into the Earth's umbra, it will appear to have a growing bite taken out of it. We will see our planet's circular shadow sweep across the face of the Moon.

Eventually the Moon will pass entirely within the Earth's umbra at 22:21, and the total eclipse will begin.

The table below lists the times when each part of the eclipse will begin and end.

Local
time
UTC
20:2500:25Moon begins to enter the Earth's penumbra
21:2201:22Moon begins to enters the Earth's umbra. Partial eclipse begins.
22:2102:21Moon fully within Earth's umbra. Total eclipse begins.
23:0903:09Midpoint of eclipse
23:5603:56Moon begins to leave the Earth's umbra. Total eclipse ends.
00:5604:56Moon fully outside the Earth's umbra. Partial eclipse ends.
01:5205:52Moon leaves the Earth's penumbra
The geometry of a lunar eclipse
The geometry of a lunar eclipse. Within the penumbra, the Earth covers some fraction of the Sun's disk, but not all of it. In the umbra, the Earth covers the entirity of the Sun's disk. Any parts of the Moon's surface that lie within the Earth's umbra will appear unilluminated. Image courtesy of F. Sogumo.

Visibility of the eclipse

Eclipses of the Moon are visible anywhere where the Moon is above the horizon at the time. Since the geometry of lunar eclipses requires that the Moon is directly opposite the Sun in the sky, the Moon can be seen above the horizon anywhere where the Sun is beneath the horizon. The map below shows where the eclipse of August 16 will be visible.

Map of where the eclipse of August 1989 will be visible.
Map of where the eclipse of August 1989 will be visible. Click here to expand.

Further information

This eclipse is a member of Saros series 128. The exact position of the Moon at the midpoint of the eclipse is as follows:

Object Right Ascension Declination Constellation Angular Size
The Moon 21h46m -13°32' Capricornus 32'29"

The coordinates above are given in J2000.0.

The sky on 19 September 2018
Sunrise
06:53
Sunset
19:11
Twilight ends
20:41
Twilight begins
05:23

10-day old moon
Waxing Gibbous

73%

10 days old

Planets
Rise Culm. Set
Mercury 06:46 13:00 19:14
Venus 10:24 15:23 20:22
Moon 16:29 21:24 01:28
Mars 16:57 21:35 02:15
Jupiter 11:19 16:25 21:31
Saturn 14:41 19:25 00:12
All times shown in EDT.

Source

Espanak, F., & Meeus, J., Five Millennium Canon of Lunar Eclipses: -1999 to +3000, NASA Technical Publication TP-2009-214172 (2009)

You may embed the map above in your own website. It is licensed under the Creative Commons Attribution 3.0 Unported license, which allows you to copy and/or modify it, so long as you credit In-The-Sky.org.

You can download it from:
https://in-the-sky.org/news/eclipses/lunar_198908.png

Related news

16 Aug 1989, 23:08 EDT  –  Full Moon
23 Aug 1989, 14:41 EDT  –  Moon at Last Quarter
31 Aug 1989, 01:46 EDT  –  New Moon
08 Sep 1989, 05:50 EDT  –  Moon at First Quarter

Image credit

© John Buonomo, North Billerica, MA.

Ashburn

Latitude:
Longitude:
Timezone:

39.04°N
77.49°W
EDT

Color scheme