Annals of Archaeology Volume 1, Issue 1, 2018, PP 30-37 King David’s Altar in Jerusalem Dated by the Bright Appearance of Comet Encke in 964 BC Göran Henriksson Department of Physics and Astronomy, Uppsala University, Box 516, SE 751 20 Uppsala, Sweden *Corresponding Author: Göran Henriksson, Department of Physics and Astronomy, Uppsala University, Box 516, SE 751 20 Uppsala, [email protected] ABSTRACT At the time corresponding to our end of May and beginning of June in 964 BC a bright comet with a very long tail dominated the night sky of the northern hemisphere. It was Comet Encke that was very bright during the Bronze Age, but today it is scarcely visible to the naked eye. It first appeared as a small comet close to the zenith, but for every night it became greater and brighter and moved slowly to the north with its tail pointing southwards. In the first week of June the tail was stretched out across the whole sky and at midnight it was visible close to the meridian. In this paper the author wishes to test the hypothesis that this appearance of Comet Encke corresponds to the motion in the sky above Jerusalem of “the sword of the Angel of the Lord”, mentioned in 1 Chronicles, in the Old Testament. Encke was first circumpolar and finally set at the northern horizon on 8 June in 964 BC at 22. This happened according to the historical chronology between 965 and 960 BC. The calculations of the orbit of Comet Encke have been performed by a computer program developed by the author. It has been calibrated from depictions on Swedish rock- carvings, Chinese texts and Sumerian cylinder seals and gives useful results at least back to 2654 BC. Keywords: Comet Encke, orbit integration, non-gravitational forces, David’s Altar, sword of the Angel of the Lord, Swedish rock-carvings, Chinese texts, Old Testament. mentioned with enough characteristic details to INTRODUCTION be uniquely identified as a known astronomical The absolute chronologies for the early Near object. Eastern cultures have been dependent on In an earlier paper, (Henriksson 2013), I have identifiable solar eclipses that have taken place used both a solar eclipse and a bright during a known year of rule of a certain king. If appearance of Comet Encke to date the Assyrian there exist a series of years of rule for kings in a King Sennaherib‟s attack in the land of Juda and country it is enough to get a single absolute year his attempt to conquer Jerusalem in 702-700 to convert the relative years to absolute years. BC. Furthermore, if a specific common year is known in relation to a king in another country, In another well-known situation, during the end an absolute chronology can also be achieved for of rule of King David, a frightening celestial that country. With this technique a common phenomena appeared above Jerusalem described absolute chronology for the Eastern as “the sword of the Angel of the Lord”. It has Mediterranean countries have been established been interpreted as the appearance of a bright during the last 200 years by a cooperation comet. Some authors have tried to identify this between historians and astronomers. I have also as Halley‟s comet as this was the only bright contributed to this during the last 20 years periodic comet known. (Henriksson 1999, 2005, 2006, 2007, 2008). THE SEARCH FOR AN EARLY BRIGHT Unfortunately, for the early history there exist COMET periods without solar eclipses preserved in the D. Justin Schove and Alan Fletcher (1987) written sources and with no reliable links write: “The early dates of Halley‟s comet have between time of rule even for important kings. been estimated by various methods with In these cases one can try to use other important inconsistent results. Schove 1955, 288 noted astronomical phenomena such as the appearance that there were 8 appearances in a millennium, of a bright supernova or a bright comet that are so that extrapolating backwards from AD Annals of Archaeology V1● I1● 2018 30 King David’s Altar in Jerusalem Dated by the Bright Appearance of Comet Encke in 964 Bc 2066±, 1066 and 66 he reached –934 or 935±5 was possible to establish roughly the plane of BC and queried whether 965 BC would be a the orbit and direction of perihelion for P/Encke suitable date for the comet of David that pointed over this interval of time. All but about 40 of the to Ornan‟s threshing-floor and led to the objects could be eliminated by comparing the building of the Temple at Jerusalem.” observed locations with possible locations of P/Encke. ….. Large uncertainties in the non- With these speculative calculations an Newtonian motion as yet prevent our certain astronomer should have a very low profile in identification of P/Encke among the remaining relation to the historical chronologies based on possibilities.” After the failure of this very comparisons with the known history of competent and ambitious attempt to identify neighboring countries even if the exact year is Encke among the detailed Chinese observation not known. A great effort to solve the problem records this problem has been considered to be with the many early indications of passages of a impossible to solve. bright comet was made by Donald K. Yeomans and Tao King (1981) when they performed an In 1994, after identification of many total solar ambitious integration of the orbit of Halley‟s eclipses on the Swedish rock-carving from the comet back to 1404 BC. They had to stop that Bronze Age (1800-500BC), I started an year because of a very close encounter with the investigation of the great number of depictions earth that made further calculations useless. of possible bright comets. The result was that all They assumed that the comet‟s non-gravitational the investigated depictions of comets can be forces remained constant from one appearance identified as Comet Encke. Fortunately, at that to the next. Nowadays, after a detailed study of time I did not know about the problems with the the Chinese and other sources, the earliest calculation of the early orbit of Encke and that it known observation of Comet Halley was made was considered as “impossible” to solve. in 240 BC. This seems to be the first appearance The identification of Encke‟s comet on the of Comet Halley in the inner solar system. Swedish rock-carvings is of course interesting In this paper I have identified David‟s comet as for the dating of them, but it is of more general Comet Encke which is expected to have been importance for the study of the evolution of extremely bright during the Bronze Age. The Encke‟s orbit and the possibility to establish problem was that it has not earlier been possible absolute chronologies for ancient cultures. A to calculate a useful orbit before 1786 when it short description of my method to calculate the was discovered with a telescope by Pierre orbit of Comet Encke and some details about the Méchain. Johann Franz Encke realized that the identified passages around 1000 BC, including a same comet had been observed in 1795, 1805 mentioning of Comet Encke in the oldest and 1818 and he computed its first orbit in 1819. Chinese cometary text, are discussed at the end This was a very difficult and laborious task and of this paper. therefore the comet was named “Encke” to honour him. The period of Encke is 3.3 years COMET ENCKE AS THE SWORD OF THE and it moves always in the inner part of the solar ANGEL OF THE LORD system and its orbit is perturbed by many I want to test the hypothesis that the motion in planets. It has weakened since the Bronze Age the sky above Jerusalem of “the sword of the and there seems to have been no observation Angel of the Lord”, mentioned in 1 Chronicles, between 1600 and 1786. It has been very in the Old Testament, was a description of difficult to determine the evolution of the non- Comet Encke‟s appearance at the end of May gravitational forces that perturbs its orbit. This and beginning of June 964 BC when it first was makes the calculations very uncertain. circumpolar and finally sets at the northern These non-gravitational accelerations are due to horizon of Jerusalem. This date is in good the rocket effect of outgassing volatiles from the agreement with known facts. icy-conglomerate nucleus proposed by Fred It is written in 1 Chronicles 21:15-16, "And God Whipple (1950). The title of his paper is: “A sent an angel to Jerusalem to destroy it, but as comet model I. The acceleration of comet he prepared to destroy it, the LORD looked and Encke”. When this model was further relented from the calamity. And He said to the developed, Whipple and Hamid (1972) tried to angel bringing the destruction, „It is enough. use it to find Comet Encke among the more than Remove your hand.‟ The angel of the LORD 300 early Chinese records of comets. They write was then standing by the threshing floor of in the abstract: “Using the Gauss-Hill method it Ornan the Jebusite. 21:16: Then David lifted up 31 Annals of Archaeology V1● I1● 2018 King David’s Altar in Jerusalem Dated by the Bright Appearance of Comet Encke in 964 Bc his eyes and saw the angel of the LORD became the Altar for the Great Temple that later standing between earth and heaven with his was built by his son Solomon.