Lunar X

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Coordinates: 25 ° 30 ′ 0 ″  S , 1 ° 6 ′ 0 ″  E

Lunar X on January 31, 2012 at 01:31 a.m. UTC (upright and laterally correct image, i.e. not as viewed through a Kepler telescope )

As Lunar X and Lunar V ( lunar means the earth's moon (Latin = "luna") are visual effects on the day-night border (terminator) of the waxing crescent moon . They are visible in the form of the letter X or V shortly before reaching the first quarter and thus once per synodic month for a good hour.

Emergence

The lighting effects are created during the sunrise on the moon by the irradiation of the edges of the moon mountains with grazing sunlight . While the surroundings are still in the shade, when looking at the surface of the moon from the earth , a high contrast arises in which a geometric figure stands out brightly from the surroundings in the shadow.

Due to the rotation of the moon , the luminous signs initially appear to float above the terminator on the night side of the moon and then increasingly merge with the illuminated day side of the moon.

In the fine arts, such light effects are also known as chiaroscuro .

discovery

Lunar X was observed, recorded and described for the first time on August 22, 2004 by David MF Chapman in Smiley's Provincial Park on Nova Scotia Route 215 near Windsor ( Nova Scotia ), Canada .

Two months earlier, on June 24, 2004, Lunar X had already been taken by Carol Lakomiak in Wisconsin , United States of America , but this picture was not released until August 29, 2004. Even before that, the effect had already been documented a number of times in photographic recordings without being explicitly mentioned.

location

Lunar X and Lunar V recorded on May 29, 2020 at 5 p.m. (UTC)

Lunar X

Lunar X appears as an extension of the lunar crater Aliacensis over the lunar crater Werner, which is about the same size, behind it at the same distance as the two lunar craters. These two lunar craters can be seen on the day side of the lunar surface before the effect occurs.

The site lies between the three lunar craters Blanchinus , La Caille and Purbach . The eastern crater wall of Purbach and the western crater wall of Blanchinus are illuminated on average 6.7 days after the new moon and produce the visual effect described.

In relation to the equator of the moon, the location is selenographically a little below the 25th southern degree of latitude and in relation to the prime meridian , which is oriented towards the middle direction to the earth ( i.e. roughly the lunar terminator on a half moon), on the 1st eastern longitude.

Lunar V

Lunar V is a converging pair of lunar ridges east of Ukert between the Mare Vaporum in the north and the Sinus Medii in the south.

The selenographic coordinates are 2.2 degrees east and 8.3 degrees north.

observation

The lighting effects can be observed from anywhere on the earth's surface if the moon is above the horizon at the appropriate time . In the vicinity of the horizon, however, the scintillation in the earth's atmosphere limits the perception of light rays .

Lunar X and Lunar V are smaller than 100 kilometers and therefore have an angular diameter of less than one arc minute . The luminous phenomena can not be seen with the naked eye and can only be observed with good binoculars or telescopes .

Because of the libration of the earth's moon, the age of the moon fluctuates by several hours when the light effect occurs.

literature

  • Alexandra Loske, Robert Massey: Moon: Art, Science, Culture , Hachette, United Kingdom, 2018, ISBN 9781781576625
  • Jonathan Powell: Rare Astronomical Sights and Sounds , from: Patrick Moore's practical astronomy series , Springer, 2018, ISBN 9783319977010

Web links

Commons : Lunar X  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d e David MF Chapman: The Lunar X Files: a fleeting vision near the crater Werner , Royal Astronomical Society of Canada (RASC) Halifax Center, Dartmouth, Nova Scotia, February 7, 2007, accessed January 5, 2020
  2. ↑ Charles A. Wood: X Marks the Spot , lunar photo of the day, August 29, 2004, accessed January 5, 2020
  3. ^ Philip S. Harrington: Cosmic Challenge: The Ultimate Observing List for Amateurs , Cambridge University Press, 2010, ISBN 9781139493680
  4. ↑ The Lunar V , The-Moon.US, April 16, 2018, accessed January 7, 2020