Sky Guide 2024 – Digital Supplements

A special digital supplement to the 2024 edition of the Sky Guide has been prepared, providing additional details that could not be included in the print edition.

1. The Sun and Moon during 2024

Supplements listing predictions for rising and setting of the Sun and the Moon, and the limits of twilight, are available for Antananarivo, Bloemfontein, Cape Town, Durban, East London, Gaborone, Harare, Johannesburg, Maputo, and Windhoek.

2. The Lunar X during 2024

The “Lunar X” is one of several fascinating optical feature on the Moon, created by the alignment of crater rims, valleys and mountain ridges, relative to the Sun. As the rising or setting Sun sweeps across the rugged lunar surface, some regions are bathed in sunlight while nearby parts are in deep shadow. For a short while, this combination of light and dark areas, seen from Earth, creates captivating shapes, patterns, or apparent structures, which can be enjoyed through binoculars and telescopes.
These phenomena are transient and dependent on the Moon’s phase, the observer’s location – and of course the local weather conditions! During 2024, there will be only one opportunity to see the Lunar X from southern Africa, on the evening of May 15.

The Lunar X is visible at the lunar terminator, the line that separates the illuminated and dark sides of the Moon. It’s formed by the sunlight striking the ridges of the craters La Caille, Blanchinus, and Purbach. It is only visible for a few hours before the first quarter phase of the Moon.

The table below predicts the times (in SAST, UT+2) during 2024 when the Lunar X begins to form. (Technically, it is the times when the Sun is 0.9° below the lunar horizon as seen from a point with coordinates –24.9° latitude, +09° longitude.)

Jan 18, 11:05 Feb 17, 01:49 Mar 17, 16:10
Apr 16, 05:41 May 15, 18:13 Jun 14, 05:49
Jul 13, 16:48 Aug 12, 03:31 Sep 10, 14:29
Oct 10, 02:09 Nov 08, 14:49 Dec 08, 04:36

For South Africa, the Lunar X will only be readily visible on 2024 May 15.

3. Locations of the planets during 2024

Star maps showing the path of the planets amongst the stars during the year are available for Mercury, Venus, Mars, Ceres, Jupiter, Saturn, Uranus, and Neptune.

4. Minor planets at opposition during 2024

Star maps showing the changing position of minor planets around their time of opposition during 2024 are available for Juno, Pallas, Vesta, Thalia, and Herculina. These small solar system denizens will be visible through binoculars.