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Tuttle

a Taken largely from Imoto and Hasegawa (1958), especially for Asian material.

b From an archaic and now disused constellation named Quadrans muralis;the radiant is in Bootes. Typical modern rate: ~80/h. c The last major shower was in 1803;Chinese records list showers on March 23, 687 b.c. (~10 "stars flew"), and March 26, 15 b.c. ("Stars fell like a shower");a similar description applies to a Korean record of an April 3, 1136 shower. Typical modern rate: 15/h.

d Five meteor showers recorded in Chinese annals are ascribed to the Aquarids. The earliest recorded shower occurred on April 8, 401. Typical modern rate: 60/h.

e Many records of Perseids are found among Chinese, Japanese, and Korean sources. The earliest firm identification is that of the shower ("more than 100 small stars flew") of the first year of the Chien Wu era, 12th moon, on the Wu-hsu (5th) day or July 17, 36 a.d. Typical modern rate: 95/h. f Widely variable (~4x) in rates of meteors from year to year. Major displays are recorded in Chinese records for September 23, 585 a.d. ("many stars chased each other"), September 25, 930, several dates in the 15th, and one in the 17th century. Typical modern rate: 30/h. g The period of comet 1866 I = Tempel-Tuttle was 33.y176. Every 33 years (with some gaps, e.g., 1933 was disappointing), the Leonids have given spectacular displays;1966 was an exceptionally strong meteor "storm." Chinese, Korean, and Japanese annals record many such displays starting on October 15 and 16, 931 a.d.

h Also called the Bielids. Meteor "storms" were seen in 1872 and 1885 with rates ~75,000 meteors/hour. Little activity has been seen since, but the nodes of the orbit undergo rapid regression.

i Phaeton is, at least at present, an asteroid. Typical modern rate: ~90/h.

The reference has been dated to March 23, 687 b.c. A second record deals with a meteorite fall. In a famous historical context, Plutarch (~120 a.d.) comments that on the night before their fateful battle at Pharsalus in 48 b.c., a "bright flaming light" was seen to pass over Julius Caesar's camp and fall into Pompey's.

Details about Chinese, Korean, and Japanese records and comments on and dates of those records are found in Imoto and Hasegawa (1958), a principal source for Table 5.8.

Whether they are observed as meteors, many meteoroids survive the passage through the atmosphere and land, at which point they are known as meteorites. In the past, there were considered three principal categories of meteorites: "stony meteorites," "stones," or aerolites; "irons" or siderites; and "stony-irons" or siderolites. These categories are still broadly useful, but meterorite taxonomy has progressed so far in recent decades and so many more categories (based on mineralogy, isotopic composition, crystal structure, and dated ages of various kinds) are recognized now, that the old categories are falling into disuse. The new categories help to identify the separate places of origin, and subsequent physical modification of the meteorites and parent bodies. Modern categories distinguish between various differenti-ated33 types of meteorites and nondifferentiated ones. But

33 The (asteroidal) meteorite parent bodies, if sufficiently large so that they retained sufficient heat at formation to completely melt, were because many references used the old categories, we will use them also, except where the physical nature of the meteorite bears on the historical context. The "stony" meteorites look much like terrestrial rocks, and after the fusion coating, produced during the frictional ablation process in the atmosphere, is eroded, may be difficult to identify and so go undetected. The irons are distinctive in appearance, often showing a dimpled appearance. In the past, although stony falls are far more numerous, iron finds were more common.

Records of meteorite falls are common and worldwide. Chinese records date back to the 7th century b.c. The Ch'un-

subject to a fractionation process whereby the denser material sank to the center, while the less dense material rose to the surface to form, respectively, a metallic core and surface crust. As collisions (particularly frequent in the early solar system) broke apart many of these parent bodies, those with an abundance of nickel and iron (the "irons"), and differentiated silicon-rich meteorites ("stony irons" and some "stony meteorites" known as achondrites) were produced from the core and nearer the surface, respectively. The largest group of meteorites, the chondrites, bear glass beads called chondrules, from the Greek chon-dros, granule, are undifferentiated, and although modified through subsequent collisions and radiation over the eons, represent an ancient form of matter dating back to the original disk from which the planets formed nearly five billion years ago. The chondrites form the bulk of the "stony" meteorites;a subset, the carbonaceous chondrites, contain water and carbon.

ch'iu ("Spring and Autumn") Chronicle, previously cited, describes an apparent meteorite fall very briefly:

16th year [of kung ('Duke') Hsi], spring, in the king's first month, day wu-shen, the first day of the month, stones fell in Sung; there were five.

The entry has been dated Dec. 24, 645 b.c. (Stephenson and Yau 1992).

The fall of a large iron meteorite was observed in China in 1064 and recorded in the "Meng Chhi Pi Than," "Dream Pool Essays" by Shen Kua in 1086 (Needham 1981, pp. 210-211):

In the first year of the Chih-Phing reign period, there was a tremendous noise like thunder at Chhang-chou about noon. A fiery star as big as the moon appeared in the South-east. In a moment there was a further thunderclap while the star moved to the south-west, and then with more thunder it fell in the garden of the Hsu family in the I-Hsing district. Fire was seen reflected in the sky far and near, and fences in the garden roundabout were all burned. When they had been extinguished, a bowl-shaped hole was seen in the ground, with the meteorite glowing within it for a long time. Even when the glow ceased it was too hot to be approached. Finally the earth was dug up, and a round stone, as big as a fist, still hot, was found, with one side elongated (i.e. pear-shaped). Its color and weight were just like iron.

Chadwick (1989) cites a passage from the Gilgamesh epic dating to the beginning of the first millennium b.c. translated by Tigay (1982, p. 270), which suggests a meteor falling to earth.

The Ionian philosopher Anaxagoras (b. ~500 b.c.) of Clazomenae, on the west coast of what is now Turkey, reported that during his 33rd year, a meteorite, which he regarded as a piece of the Sun, fell in broad daylight near the small town of Aegospotami. It was large enough to fill a wagon. He regarded both the stars and the Sun as incandescent stones, with the latter being larger than the Peloponnese.

Momentous events such as eclipses and fireballs have always impressed and awed people through history. To a religious person, all events are signs, a disposition that has resulted in pious and ethical behavior as well as astrological practice, as we note in §15. Meteorite falls as events that were taken as religious signs.

In the New Testament book of Acts, Paul arouses the passions of the artisans and merchants of Ephesus, who recognized the threat that Christianity posed to the worship of Artemis, and the business activity associated with it; the city is described as being the "temple keeper" of the goddess and of "the great stone that fell from the sky" (Acts 19:35).34 Artemis was often depicted as a many-breasted goddess, a possible, if mythic, reference to the appearance of a large iron meteorite (see also comments by Wood 1968 or Wasson 1985).

The "image" of the Syro-Phoenician Sun-god, a black meteorite set among precious gems, was carried in a procession in Rome, when its priest, Heliogabalus, was named Emperor of Rome in 218 a.d.

34 The phrase "AptsiiiSoi; Kai tov Sioreetouv" (Nestle 1858/1953) is interpreted as "the image of Artemis fallen from Heaven" (Arndt and Gingrich 1952/1957, p. 198).

The black stone of the Kaaba in Mecca, sacred to Muslims, has been suggested to be a meteorite also (Wood 1968, p. 2).

Dall'olmo (1978) notes many records of meteorites from medieval Europe: ~453 (Thrace); 874 ("very big stones"); 921 (Italy, "many stones"); 950/952 (Augsburg, "falling mass of iron"—"followed by noise"); 998 (-Magdeburg, "two inflamed stones"); 1094 or 1095 (Gallia, a meteor seen during a meteor shower fell into a marshy area and sizzled); 1135 (Duringia in Germany, a stone as big as a house half-buried itself and burned for three days, but, mysteriously, a "terrible" noise lasted three days before it fell); 1136 (Altesleibon in Germany, a stone the size of a man's head); 1143, June 15 (Mt. Brisach, fell from a clear sky in front of the church doors); 1481 (reported in Genoa that a stone of weight "1000" fell). An existing woodcut depicts a "thunderstone" observed to fall on the town of Ensisheim, Alsace, on November 7, 1492 (Wasson 1985, p. 3).

Dall'olmo's (1978) records include a number of references to meteors as dragons, as a result of sparks, flames, or smoke. The first such reference is to the Augsburg meteor of 950 or 952; others are recorded in the years 956 ("dragon without a head"); 1130 Oct. 15 ("signum draconis"; "quoddam monstrum" in two sources); 1202 Sept. 6 ("almost like a dragon"); 1239 July 24 (a bright star like Venus appeared at sunset, with fire and smoke left behind; also considered a comet and a dragon); 1241 July 11 (dragon with thin, red tail); 1280 Mar. 18 (a flying dragon with long tail, seen after a lunar eclipse). In addition, there are many references to writhing, snake-like tails, as the debris train encounters upper atmospheric winds. An astronomical source for the myth of the dragon is strongly suggested, but Oriental references are required to make the claim universal.

Despite overwhelming historical evidence, the notion that objects from space could actually fall to Earth was not readily accepted by the rational 18th century. After a report by Professors Siliman and Kingley, both at Yale, that a meteorite had been recovered at Weston, Connecticut, on Dec. 14, 1807, Thomas Jefferson is reputed to have commented acerbically that "it is easier to believe that two Yankee professors would lie than that stones would fall from heaven" (Wood 1968, p. 4). Although the comment has never been verified, a letter written by Jefferson two months after the sighting does discuss the matter, albeit expressing a more open view of the truth or falsity of the event (Wasson 1985, p. 4).

Many meteor craters are now known, and the meteors associated with several of these must have fallen during the past 50,000 years. Two small meteor craters (-100 m across, 12m deep, and -50m wide, 9m deep), amid smaller ones buried by sand dunes, were found in the Rub' al Khali, the "Empty Quarter," of Saudi Arabia during H. St. J. Philby's 1932 search for the "lost city" of Wabar, which was alleged to have been "destroyed by fire from heaven" (Baldwin 1963, p. 35) in Arabic traditions. Extensive iron meteorite fragments have been found in the area. More than a dozen craters have been found near Henbury, Australia; iron meteorites have been recovered, and the presence of extensive oxidation of the meteorites, and their C14 content, suggest ages of at least several thousands of years. The aboriginal name for the place is chindu chinna waru chingi yabu, "Sun walk fire devil rock," and natives would not camp within miles of the craters (Baldwin 1963, pp. 28-29). In the beginning of the 18th century, nomads near Murgab in what is now Tazhikistan, witnessed the impact of two large meteorites. The craters are 80 and 16 m across, and the larger is 15 m deep. The area is called Chaglan Toushtou, "place where lightning fell." Odessa, Texas, and Haviland, Kansas, are sites of other craters of relatively recent age. Two major impacts were witnessed in Siberia in this century: in Tunguska, an explosion rated at 9-1016 J, equivalent to a 22 Megaton bomb, occurred in 1908, and another observed on February 12, 1947, was rated at ~7 x 1013 J (Baldwin 1963), equivalent to 17 KT. A smaller such event may have taken place around the Peruvian-Brazilian frontier on the morning of August 13, 1930 (Bailey 1995). A delightful account and update is given by Huyghe (1996). These events do not appear to involve meteoroids (no major bodies have been discovered from the Siberian event despite extensive searches; the South American has been less well studied, but thus far nothing has been found). Small comets, loose aggregations of dust and ices with densities less than 1 g/cm3, (1000 kg/m3), would not easily survive impact intact and are likely candidates for the colliding bodies in these two cases.

With the widespread publicity received by the Levy-Shoemaker 9 cometary impacts on Jupiter, with more and more frequent reports of near-Earth trajectories by mete-oroids, and with accumulating evidence for the impact theory of extinctions recorded in the geological record of the Earth's crust, the catastrophism theory of evolution (as opposed to uniformitarianism) has been resurrected, more than a century and a half after it was disdainfully dismissed by Charles Lyell (~1830) in his Principles of Geology. Impacts by asteroids or comets are now thought to have played a major role in the punctuation, so to speak, of the geological record. Further details on meteorite craters can be found in Hodge (1994).

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