The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.

Lunar occultation of Beta1 Scorpii

Dominic Ford, Editor
From the Lunar Occultations feed

Objects: Acrab

The Moon will pass in front of Beta1 Scorpii (Acrab), creating a lunar occultation visible from countries and territories including the Contiguous United States, Mexico, Honduras and Guatemala amongst others.

Unfortunately the occultation will not be visible from Fairfield, though it will be visible elsewhere in the Contiguous United States anda close conjunction between the pair will be more widely visible.

The map below shows the visibility of the occultation across the world. Separate contours show where the disappearance of Beta1 Scorpii (Acrab) is visible (shown in red), and where its reappearance is visible (shown in blue). 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.

Map showing where the occultation is visible

Outside of the contours, the Moon does not pass in front of Beta1 Scorpii (Acrab) at any time, or is below the horizon at the time of the occultation. However, a close conjunction between the pair may be visible.

The map can be downloaded in PNG , PDF or SVG format. A KMZ file , is also available, which can be opened in Google Earth to provide a higher resolution map.

A complete list of the countries and territories where the occultation will be visible is as follows:

Country Time span
The Contiguous United States 06:18–06:08
Mexico 05:34–05:17
Honduras 05:35–09:09
Guatemala 05:33–22:36
Nicaragua 05:34–09:10
Belize 05:39–22:34
El Salvador 05:33–08:50
Cuba 06:02–22:54
Costa Rica 05:33–09:03
Canada 18:42–06:48
Clipperton Island 05:27–22:24

Lunar occultations are only ever visible from a small fraction of the Earth's surface. 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 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.

The position of Beta1 Scorpii (Acrab) at the moment of the occultation will be as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
Beta1 Scorpii (Acrab) 16h05m20s 19°48'S Scorpius 2.6 0'00"

The coordinates above are given in J2000.0.

Next/previous occultations

« Previous Next »
Visible from the Contiguous United States Worldwide Worldwide Visible from the Contiguous United States
25 May 2013 25 Aug 2020 Occultations of Beta1 Scorpii (Acrab) 19 Oct 2020 09 Jan 2032
18 Feb 2020 06 Sep 2020 Occultations 03 Oct 2020 12 Dec 2020

The sky on 21 Sep 2020

The sky on 21 September 2020
Twilight ends
Twilight begins

4-day old moon
Waxing Crescent


4 days old

Rise Culm. Set
Mercury 08:44 14:10 19:36
Venus 03:06 10:06 17:05
Moon 11:34 16:42 21:43
Mars 20:09 02:36 09:02
Jupiter 15:25 20:02 00:40
Saturn 15:52 20:36 01:19
All times shown in EDT.


The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).

This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.

Image credit

The Moon in conjunction with Venus and Jupiter, with the Very Large Telescope in the foreground. Image © Y. Beletsky, ESO, 2009.






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