Anasazi Supernova Observations

Chaco Canyon Petroglyph May Record 1054 Birth of the Crab Nebula

Jun 10, 2007 Paul A. Heckert

A petroglyph in Chaco Canyon, New Mexico may be an Anasazi record of the supernova that formed the Crab Nebula.

Crab Nebula Supernova

A supernova occurring on July 4, 1054 formed the Crab Nebula, a well known supernova remnant in Taurus. The ancient Chinese recorded detailed observations. It was a previously unseen star that was bright enough to be visible in the daytime for 23 days and took almost 2 years to disappear from view. A petroglyph found at Anasazi ruins in western New Mexico, may record this stellar explosion.

Anasazi at Chaco Canyon

The Anasazi, meaning the old ones, are ancestors of the modern day Pueblo people of the American southwest. The ruins of their civilization that flourished about 1000 AD can be found at Chaco Canyon and other sites around New Mexico and Arizona. The ruins at Chaco Canyon indicating a sophisticated knowledge of the night sky include numerous alignments marking the position of the sunrise or sunset at key times of the year such as the solstices and equinoxes.

As societies, including the Anasazi, evolved from hunting gathering into less nomadic agricultural societies they needed to know when to plant their crops. Hot desert summers and cold high altitude winters make the Chaco Canyon climate unforgiving. Crops planted at the wrong time would yield a poor harvest causing many tribe members to starve. The earliest systematic astronomical observations were likely motivated by this need for a calendar. Survival is a strong motivator, so the Anasazi, and other ancient societies knew the night sky very well.

Anasazi Observations of the Crab Nebula Supernova

The Anasazi may have observed and recorded the supernova that formed the Crab Nebula. A petroglyph at Chaco Canyon shows what appears to be a crescent moon and a very bright star. Why would this be the Crab Nebula supernova?

The Moon's stable orbit allows us to compute its phase and location in the sky for any date. On July 5, 1054, the crescent moon was very near the position of the Crab Nebula supernova. Visible in the evening sky during winter, Taurus is a winter constellation. In July however it just peeks above the eastern horizon in the predawn hours. Before dawn on the early morning of July 5, 1054, Taurus must have been truly spectacular with the addition of the crescent moon to the previous day's supernova.

Imagine the awe felt by Anazasi arising before dawn to start the day's chores. Early July marks the end of the dry season and the beginning of the monsoon season in New Mexico. During the monsoons however, the thundershowers occur in the late afternoon. By dawn the previous day's thunderclouds have completely dissipated. The Anasazi awoke to crisp clear desert skies with nothing to obscure the spectacularly bright new star and crescent moon low in the eastern sky decorating Taurus like jewels. In awe the Anasazi watched the eastern sky begin to glow. As the first faint eastern glow drifted higher, the horizon gradually brightened. Behind them the Earth's shadow formed a dark band along the western horizon. Soon the bright eastern band began to glow brightly enough to show colors: a pale green, a faint but deep violet, and finally a brilliant orange red. As dawn's red glare inched above the horizon, the stars winked out as they were slowly obscured by the Sun's light. The crescent moon and the bright new star however remained visible in the full daylight.

The following morning the crescent moon was thinner and lower in the sky. The spectacularly bright new star still appeared in the same spot, were it remained until it gradually faded from view nearly two years later. Apparently the Anazasi were so moved by this spectacular sight that they were compelled to record the event as the petroglyph still visible at Chaco Canyon.

The need to record spectacular events is universal and old as mankind. Cultures as diverse as the Anasazi and ancient Chinese recorded this spectacular stellar appearance. There are however, for some unaccountable reason, no known records of this event from western civilization.

Further Reading

Zeilik, Michael, Astronomy the Evolving Universe, 9th edition, Cambridge, 2002. The 9th edition has the latest information about supernovae; earlier editions have more information about the Anazasi petroglyph.

The copyright of the article Anasazi Supernova Observations in Astronomy & Space is owned by Paul A. Heckert. Permission to republish Anasazi Supernova Observations in print or online must be granted by the author in writing.