While perusing the minor-planet sections of NASA's Website, thanks to Patrick's asteroid, I came upon this text, written by Paul Schlyter. It is concerned with debris "clouds" at the Trojan points of the lunar orbit. If you've seen the Gegenschein and zodiacal light, here's the next goal. The best search strategy would be to look when the Trojan point is in a relatively barren part of the sky and not near the anti-solar point or zodiacal light itself. Any Milky Way extensions would make it impossible to identify the Trojan glow. Anybody seen this phenomenon? Schlyter wrote: "In addition to ephemeral satellites there are two more possibilities. One is that the Moon had a satellite of its own -- but despite several searches none has been found (in addition it's now known that the gravity field of the Moon is uneven or "lumpy" enough for any lunar satellite orbit to be unstable -- any lunar satellite will therefore crash into the Moon after a fairly short time, a few years or possibly a decade). The other possibility is that there might be Trojan satellites, i.e. secondary satellites in the lunar orbit, travelling 60 degrees ahead of or behind the Moon. Such "Trojan satellites" were first reported by the Polish astronomer Kordylewski of Krakow observatory. He started his search in 1951, visually with a good telescope. He was hoping for reasonably large bodies in the lunar orbit, 60 degrees away from the Moon. The search was negative, but in 1956 his compatriot and colleague, Wilkowski, suggested that there may be many tiny bodies, too small to be seen individually but many enough to appear as a cloud of dust particles. In such a case, they would be best visible without a telescope i.e. with the unaided eye! Using a telescope would "magnify it out of existence". Dr Kordylewski was willing to try. A dark night with clear skies, and the Moon being below the horizon, was required. In October 1956, Kordylewski saw, for the first time, a fairly bright patch in one of the two positions. It was not small, subtending an angle of 2 degrees (i.e. about 4 times larger than the Moon itself), and was very faint, only about half as bright as the notoriously difficult Gegenschein (counterglow -- a bright patch in the zodiacal light, directly opposite to the Sun). In March and April 1961, Kordylewski succeeded in photographing two clouds near the expected positions. They seem to vary in extent, but that may be due to changing illumination. J. Roach detected these cloud satellites in 1975 with the OSO (Orbiting Solar Observatory) 6 spacecraft. In 1990 they were again photographed, this time by the Polish astronomer Winiarski, who found that they were a few degrees in apparent diameter, that they "wandered" up to ten degrees away from the "trojan" point, and that they were somewhat redder than the zodiacal light." ____________________________________________________________________________________ No need to miss a message. Get email on-the-go with Yahoo! Mail for Mobile. Get started. http://mobile.yahoo.com/mail