The recent well-advertised Perseid meteor display prompted a few thoughts about the moon and meteors. The moon's bright light can seriously affect meteor counts, and meteor observers always consult their astronomical diaries to see whether the moon will be prominent at the dates of the various annual meteor showers. A Full Moon will allow only the brightest meteors to be spotted. The same curses uttered at Luna from the lips of ardent meteor watchers are also spoken by Deep Sky observers. Some years ago I actually heard one amateur astronomer say "I hate the moon! I really detest it! You can't do any serious astronomy when that thing's around!"
It never occurs to these "Mooncussers" that there's plenty of interest to hold anyone's attention up there on the lunar surface.The mooncussers may take some consolation with the fact that meteorites are one of the main causes of erosion on the moon. There are no meteor flashes ever visible in the skies of airless moon, and every moon-bound meteoroid hits the surface at its original interplanetary velocity. Like sandblasting, millions of meteoroids and micrometeoroids scour the lunar surface at over 100,000 km/hr. Each tiny hit vapourises a small portion of the surface, wearing-down solid rock and producing the fine lunar soil.
The early space pioneers saw meteoroids as a potential hazard to manned lunar exploration. One book states "the suit for work on the moon will not be a suit at all, but something like a small army tank!....the original rocket, of course, will have sides that are stout and thick enough to resist any meteorite it is likely to meet". In fact, micrometeoroids were later downgraded in the risk-to-safety stakes; the Apollo spacesuit, with layers of sandwiched Kevlar ("integrated thermal micrometeoroid garment") was fairly comfortable and protective. However, the lunar lander was a very flimsy affair, and despite its apparent solidity it had paper-thin metal walls.
Onto observing, now. Bob Paterson (Newbury) continues to make detailed lunar observations accompanied by clear written notes. Observations were made of Eratosthenes, Clavius and the South Polar region (Feb 1); Faraday/Stoffler/Fernelius and Albategnius on the terminator (Feb 28); the northeastern quadrant of the moon (including Mare Humboldtianum on April 1); Posidonius and the near-terminator Madler-Beaumont region (April 26); Tycho, Rima Hesiodus, Pitatus and Clavius (in what Bob appropriately calls an "orgy of observing" on 30 April); J.Herschel (May 2); Phocylides/Schickard, Anaximander/Pythagoras (May 3); Lunar Alps (including estimated mountain cross-section on May 28); J.Herschel (June 1); Deslandres (June 27); Agrippa (July 25); Schickard(and estimated profile of crater July 30); South Polar region near terminator (July 31). Altogether, Bob has done a very impressive amount of lunar research.
Marcus Buffrey (Monmouth) observed Gassendi on March 4 with a 60mm refractor, and noted that its floor has apparently been flooded with lavas from Mare Humorum. Clavius was observed on April 13, and Marcus noted the prominent arc of large craters running across its floor. On April 29 the Ptolemaeus chain was observed, and on the following evening the deeply-shadow-filled Copernicus was surveyed, its inner western wall showing a certain amount of terracing. Afterwards Marcus writes of his thrill at seeing the majestic Alpine Valley for the very first time.
James Lunny (Motherwell) using his 100mm OG observed the walled plain Messala on March 25, noting subtle floor tonal variations and a prominent "wishbone" shadow created by its walls.David Scanlan (Cosham, Portsmouth) observed Stevinus (April 25, 10x50 binoculars). With a 75mm OG David observed Aristillus (Feb 28); Cook (March 27); Macrobius, noting internal floor detail (June 28); Picard (July 2); Mare Crisium (July 30).James Clarke (Warrington) sent in a good series of coloured pencil sketches of last December's total eclipse (better late than never!) which leads me to give here an early prompt regarding the forthcoming lunar eclipse - make a date for the pre-dawn skies of November 29 (see October's Popular Astronomy). This will be the last total lunar eclipse visible for two and a half years.
