Lunar Occultation

by Dominic Ford, Editor
Last updated: 16 Jul 2020
Lunar Occultation

The Moon occults Saturn in 2008 May. Image © Thomas Bresson.

A lunar occultation occurs when the Moon passes in front of a star or other astronomical object. Occultations of bright stars and planets typically occur a few times per year, often clustering with several occultations of the same object in successive months, since the Moon traces roughly the same path across the sky each month. These clusters come to an end after a few months, when gradual changes in the Moon's orbit change the Moon's path across the sky. Alternatively, in the case of planets, the planet's own movement will eventually carry it away from the Moon's path.

Since the Moon is much closer to the Earth than other celestial objects, its exact position in the sky differs depending on your exact location on Earth due to its large parallax. The position of the Moon as seen from two points on opposite sides of the Earth varies by up to two degrees, or four times the diameter of the full moon.

This means that no single lunar occultation can ever be visible across the whole Earth: if the Moon is aligned to pass in front of a particular object for an observer on one side of the Earth, it will appear up to two degrees away from that object on the other side of the Earth.

In-The-Sky.org lists all lunar occultations of the planets and stars brighter than second magnitude, and provides maps of where each occultation is visible. Each map shows separate contours for where the disappearance of the occulted object behind the Moon is visible (shown in red), and where its reappearance is visible (shown in blue). The solid contours show where each event is likely to be visible through binoculars at a reasonable altitude in the sky. Dotted contours indicate where each event occurs above the horizon, but may not be visible due to the sky being too bright or the Moon being very close to the horizon.

The KMZ files below can be opened in Google Earth to provide a more high-resolution view.

List of lunar occultations

The table below lists lunar occultations of the planets and stars brighter than second magnitude in 2020. To show events in other years, use the control below.

Change year

Lunar occultations in 2020

Date Visibility from
Ashburn
Disappear Reappear Object Visibility
map
Date Visibility from
Ashburn
Disappear Reappear Object Visibility
map
23 Jan 2020 Not visibleJupiterPNG | PDF | SVG | KMZMore »
18 Feb 2020 In daylight07:26 EST08:59 ESTMarsPNG | PDF | SVG | KMZMore »
19 Feb 2020 Not visibleJupiterPNG | PDF | SVG | KMZMore »
18 Mar 2020 Not visibleMarsPNG | PDF | SVG | KMZMore »
19 Jun 2020 Not visibleVenusPNG | PDF | SVG | KMZMore »
09 Aug 2020 Not visibleMarsPNG | PDF | SVG | KMZMore »
06 Sep 2020 Not visibleMarsPNG | PDF | SVG | KMZMore »
03 Oct 2020 Not visibleMarsPNG | PDF | SVG | KMZMore »
12 Dec 2020 Not visibleVenusPNG | PDF | SVG | KMZMore »

Ashburn

Latitude:
Longitude:
Timezone:

39.04°N
77.49°W
EDT

Color scheme