© John Buonomo, North Billerica, MA.

Total lunar eclipse

Fri, 27 Jul 2018 at16:22 EDT(487 days away)
20:22 UTC

Dominic Ford, Editor
From the Eclipses feed

Time:       Altitude: °      Azimuth: °

A simulation of how the eclipse will appear from Newark.

The outer grey circle is the Earth's penumbra, and the inner red circle is the umbra. Any part of the Moon which passes within the red circle will be unilluminated, while any part within the grey circle will appear less bright than usual.

There will be a total eclipse of the Moon, though it will not be visible from Newark since the Moon will be beneath the horizon at the time.

The Moon will be totally eclipsed from 15:30 until 17:13, and there will be a partial eclipse visible from 14:25 until 18:19 (all times given in Newark 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 13:15, 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 14:25, 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 15:30, and the total eclipse will begin.

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

13:1517:15Moon begins to enter the Earth's penumbra
14:2518:25Moon begins to enters the Earth's umbra. Partial eclipse begins.
15:3019:30Moon fully within Earth's umbra. Total eclipse begins.
16:2220:22Midpoint of eclipse
17:1321:13Moon begins to leave the Earth's umbra. Total eclipse ends.
18:1922:19Moon fully outside the Earth's umbra. Partial eclipse ends.
19:2823:28Moon 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 July 27 will be visible.

Map of where the eclipse of July 2018 will be visible.
Map of where the eclipse of July 2018 will be visible. Click here to expand.

Further information

This eclipse is a member of Saros series 129. The exact position of the Moon at the midpoint of the eclipse is as follows:

Object Right Ascension Declination Constellation Angular Size
The Moon 20h27m -19°01' Capricornus 29'24"

The coordinates above are given in J2000.0.

The sky on 27 July 2018
Sunrise: 05:47
Sunset: 20:16
from 03:54
until 22:10

14-day old moon
Age of Moon:
14 days

All times shown in EDT.
Rise Culm. Set
Mercury 07:33 14:11 20:50
Venus 09:36 15:55 22:14
Moon 20:22 00:31 05:21
Mars 20:37 01:08 05:35
Jupiter 14:09 19:19 00:33
Saturn 18:09 22:49 03:32


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:

Related news

27 Jul 2018, 16:22 EDTFull Moon
04 Aug 2018, 14:19 EDTMoon at Last Quarter
11 Aug 2018, 05:59 EDTNew Moon
18 Aug 2018, 03:50 EDTMoon at First Quarter

Image credit

© John Buonomo, North Billerica, MA.




Color scheme