by Dr. Wm. Bruce Weaver |
|
A hand
and compass provide scale for a petroglyph of probable |
| One of the defining properties of the
human race must be our fascination with the wonders and beauty of the night sky and the
reassuring regularities of the motions of celestial bodies. Some ancient peoples, such as
those who built the henges of the British Isles (the famous Stonehenge is the most famous
example of these structures), left almost no other evidence of their existence but their
monuments to motions of the Sun and Moon. Certainly no evidence that showed such a high
level of sophistication in record keeping, mathematical analysis, engineering, politics,
and the many other skills required to observe (in England!) and design and build the
megalithic calculators. Although there are numerous astronomically related archaeological artifacts in South America and in Mesoamerica, there are relatively few in North America. So, when Anne McConnell, long-time FOM, asked me to examine a petroglyph on a rock in the Lone Grapevine area of the Red Rock National Conservation area just west of Las Vegas, I thought it was a great opportunity. |
|
Anthropologist
Eileen Green points north by a fine collection of petroglyphs. |
| Early one morning this April, Anne and
our party were met at the site by anthropologist Eileen Green, whose area of expertise is
rock art of southern Nevada. Eileen had found a petroglyph which she felt had astronomical
significance and hoped that I could link it to the famous supernova of 1054 A.D. This
would provide her with a specific date for a group of petroglyphs. Her hope was inspired by the suggestion by astronomers John Brandt and Ray Williamson that a petroglyph of a crescent moon near a bright star discovered in Chaco Canyon in New Mexico depicted the observation of the famous supernova by the Anasazi. Although it could be such an observation, others have postulated that it is a representation of a more commonly observed conjunction of a crescent moon with a bright apparition of Venus. |
|
Unmistakable cowboys amongst the sheep help date this rock art. |
|
Sheep are
the most common figure in these petroglyphs. |
| This spring had been kind to Las Vegas and almost every type of plant in the area seemed to be in bloom. It took a while to find the petroglyph in question in an area rich with Native American rock art. The ages of the art clearly spanned quite a range of times. Some depicted scenes that included figures with distinctive cowboy hats while others were barely visible after many years of aging. |
| After a tour of several fascinating
rocks, some covered with layers of art, we came upon the rock in question. I knew at first
glance that it was not related to any supernovae. It is almost certainly a depiction of a
bright meteor, quite possibly a bolide (an exploding meteor). A check of a compass showed the artist was facing almost due east when the drawing was made. This is the direction of rising meteor shower radiants. The appearance of the petroglyph strongly reminded me of a Perseid meteor so I couldn't resist saying "I can't tell you what year this was chipped into the rock but I can tell you that it might very well have been done in the month of August." A long silence followed while my companions tried to decide if I had been under the Nevada Sun too long or I had some nearly magical insight into this art. Of course, I soon had to explain that it was only a little more likely it was done on some distant fall evening rather than some other time of the year. It's my impression that there is already enough highly imaginative interpretation of the art of Native Americans without starting a new area of speculation. Eileen was delighted that I was able to provide a (relatively) confident identification of the inspiration for the petroglyph. Like most parts of America, this area had been populated by a succession of people. Had it been done by the people we call the Desert Archaic people, the lower Colorado River people, the Puebloans, Fremonts, or the Shoshone/Paiutes? So far there is no way of telling. |
|
With the
petroglyph of interest in the foreground and the dry Nevada desert behind, |
| Is this the end of MIRA's
foray into archaeoastronomy? I hope not. Looking through Anne's many photographs of
southwestern petroglyph sites, I noticed several sites had areas where several rows of
hash marks were inscribed. What was interesting to me is that the typical number of marks
per row was about 30 -- a number suggestive of the number of days in a lunar month.
Depending on weather and astronomical details, it may be hard to determine the exact
number of days for any one month. However, if the person is recording successive months,
the average number of days must converge to the correct number (including the fractional
part). Thus, we might be able to make a very confident determination as to whether the hash marks are used to determine the lunar cycle. Gosh, this is fun. |
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