: See this thread for background on this project: Moon Zoo ChallengeLocation: Site 1:
Reiner Gamma (56.8W, ~14N) [Latitude: 14 Longitude: -56.8]. Site 2:
Mare Ingenii (166.1E, 36.0S) [Latitude: -36.0 Longitude: 166.1].
and other sites e.g. Mare Marginis.Images:
Reiner Gamma swirl - M117874527ME
Butterfly swirl - M103439292MCDiscovery:
Lunar Orbiter era and possibly earlierDescription:
Light and dark adjacent broad curves, often described as swirls. Do not get confused with radial crater rays! So far these are seen on dark mare with no discernable difference in surface texture when examined close up. To date all known swirls have been seen over large areas and not small km size regions. These are best seen in images with little shadow.Interest:
Each swirl site is believed to sit over a local magnetic field that sets up a mini- magnetosphere, strong enough to deflect at least some solar wind particles and reduce space weathering of the soil. The latest theory is that electric fields above the lunar surface help to sweep the surface clean of charged dust particles. It would be interesting to identify new candidate sites and to see what different sizes they come in, where they are located, are any in highland areas, and also to monitor them at different times to see if changes in dust deposits can be observed.
Two of the swirls on the far side of the Moon are directly opposite the centres of two large near side impact basins, Mare Imbrium and Mare Orientale. So there appears to be some connection with a large impact causing a swirl to appear on the opposite side of the Moon.External References: NASA Science News; Lunar SwirlsThe Lunar Swirls - PDF documentVarieties of Lunar Swirls - PDF document
Reiner Gamma swirl (7.4 N, 300.9 E)
(LROC WAC M114342152CE)
| ~ |
“Butterfly swirl” in Mare Ingenii (directly opposite Mare Imbrium).
(LROC WAC M103439292MC)
If you find what you think is a lunar swirl please post it in this thread.
Don't forget a picture, the strip reference (LROC / NAC reference) and the approximate latitude and longitude.