 Print of the 1783 Great Meteor by Paul Sandby (1731–1809). Original in the collection of the Hunterian Museum and Art Gallery | |
| Date | 18 August 1783 |
|---|---|
| Location | British Isles |
The 1783 Great Meteor was a meteor procession observed on 18 August 1783 from the British Isles, at a time when such phenomena were not well understood. The meteor was the subject of much discussion in the Philosophical Transactions of the Royal Society and was the subject of a detailed study by Charles Blagden.
The event occurred between 21:15 and 21:30 on 18 August 1783, a clear, dry night. Analysis of observations has indicated that the meteor entered Earth's atmosphere over the North Sea, before passing over the east coast of Scotland and England and the English Channel; it finally broke up, after a passage within the atmosphere of around a thousand miles (around 1600 km), over south-western France or northern Italy. [1]
There were many witnesses. Perhaps the most prominent was Tiberius Cavallo, an Italian natural philosopher who had happened to be amongst a group of people on the terrace at Windsor Castle at the time the meteor appeared. Cavallo published his account of the phenomenon in v. 74 of the Philosophical Transactions :
Some flashes of lambent light, much like the aurora borealis , were first observed on the northern part of the heavens, which were soon perceived to proceed from a roundish luminous body, whose apparent diameter equaled half that of the moon, and almost stationary in the same point of the heavens [...] This ball at first appeared of a faint bluish light, perhaps from appearing just kindled, or from its appearing through the haziness; but it gradually increased its light, and soon began to move, at first ascending above the horizon in an oblique direction towards the east. Its course in this direction was very short, perhaps of five or six degrees; after which it directed its course towards the east [...] Its light was prodigious. Every object appeared very distinct; the whole face of the country, in that beautiful prospect before the terrace, being instantly illuminated. [2]
Cavallo noted both that the meteor, which was visible for around thirty seconds in total, appeared to split into several smaller bodies (a meteor procession) immediately following the main mass and that a rumbling noise, "as it were of thunder at a great distance", was heard around ten minutes after the meteor appeared, which he speculated "was the report of the meteor's explosion". Other accounts, such as those of Alexander Aubert and Richard Lovell Edgeworth, noted red and blue colour tints in the fireball. [3] [4]
Some accounts appeared rather more fanciful; the London Magazine mentioned a letter by a lieutenant on a British warship which had been positioned north of Ireland "who relates he saw the same meteor moving along the north-east quarter [...] but he adds something singular enough, namely, that a little time afterwards, he saw it moving back again, the contrary way to which it came". [5] The author added that "several other observations of this meteor have come into my hands, but they are so inconsistent with these already related, as well as with one another, that I forebear to mention them". [6]
Gilbert White, writing in 1787, was to remember the "amazing and portentous" summer of 1783 as "full of horrible phaenomena [...] alarming meteors and tremendous thunder-storms that affrighted and distressed the different counties of this kingdom". [7]
One of Cavallo's five companions on the terrace was the artist Thomas Sandby, who in collaboration with his brother Paul based a now well-known engraving on the event. [8] A print [9] of this engraving is in the collection of the Hunterian Museum and Art Gallery at Glasgow University. A second engraving was produced by a schoolmaster, Henry Robinson, who observed the meteor from the village of Winthorpe, Nottinghamshire. [10] Further engravings, based on the drawings of the authors and presented in a fold-out form, were included with articles by Cavallo and Nathaniel Pigott in the Philosophical Transactions. [11]
A painting traditionally thought to be of the 1759 apparition of Halley's Comet and attributed to the "English Canaletto", Samuel Scott, has in more recent years been interpreted as depicting a large fireball meteor given its generally uncometary appearance. [12] Further work by Jay Pasachoff and Roberta Olson has suggested that the painting is not in fact by Scott, and that it depicts the third stage of the 1783 fireball, viewed over the Thames. [13]
It has been speculated that the Hambleton Pallasite, a rare type of meteorite found in 2005 in Hambleton, North Yorkshire, may be related to the 1783 Great Meteor, based on the latter's track, and on weathering on the pallasite's surface. [14] In support of this, in 2008 the terrestrial age of the Hambleton meteorite was determined to be around 225 years.[ citation needed ]
The Leonids are a prolific annual meteor shower associated with the comet Tempel–Tuttle, and are also known for their spectacular meteor storms that occur about every 33 years. The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to radiate from that point in the sky. Their proper Greek name should be Leontids, but the word was initially constructed as a Greek/Latin hybrid and it has been used since. The meteor shower peak should be on 17 November, but any outburst in 2023 is likely to be from the 1767 meteoroid stream.
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
Halley's Comet, Comet Halley, or sometimes simply Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the only naked-eye comet that can appear twice in a human lifetime. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.
A meteoroid is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than meteoroids are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars.
A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller than a grain of sand, so almost all of them disintegrate and never hit the Earth's surface. Very intense or unusual meteor showers are known as meteor outbursts and meteor storms, which produce at least 1,000 meteors an hour, most notably from the Leonids. The Meteor Data Centre lists over 900 suspected meteor showers of which about 100 are well established. Several organizations point to viewing opportunities on the Internet. NASA maintains a daily map of active meteor showers.
The year 1783 in science and technology involved some significant events:
Comet Encke, or Encke's Comet, is a periodic comet that completes an orbit of the Sun once every 3.3 years. Encke was first recorded by Pierre Méchain on 17 January 1786, but it was not recognized as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke. Like Halley's Comet, it is unusual in its being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light its nucleus receives, although comets generate a large coma and tail that can make them much more visible during their perihelion. The diameter of the nucleus of Encke's Comet is 4.8 km.
Biela's Comet or Comet Biela was a periodic Jupiter-family comet first recorded in 1772 by Montaigne and Messier and finally identified as periodic in 1826 by Wilhelm von Biela. It was subsequently observed to split in two and has not been seen since 1852. As a result, it is currently considered to have been destroyed, although remnants appeared to have survived for some time as a meteor shower, the Andromedids.
The Baily's beads effect and diamond ring effect are features of total and annular solar eclipses. Although caused by the same phenomenon, they are two distinct events during these types of solar eclipses. As the Moon covers the Sun during a solar eclipse, the rugged topography of the lunar limb allows beads of sunlight to shine through in some places while not in others. The effect is named after Francis Baily, who explained the phenomenon in 1836. The diamond ring effect is seen when only one bead is left, appearing as a shining "diamond" set in a bright ring around the lunar silhouette.
The pallasites are a class of stony–iron meteorite. They are relatively rare, and can be distinguished by the presence of large olivine crystal inclusions in the ferro-nickel matrix.
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The Great Daylight Fireball was an Earth-grazing fireball that passed within 57 kilometres of Earth's surface at 20:29 UTC on August 10, 1972. It entered Earth's atmosphere at a speed of 15 kilometres per second (9.3 mi/s) in daylight over Utah, United States and passed northwards leaving the atmosphere over Alberta, Canada. It was seen by many people and recorded on film and by space-borne sensors. An eyewitness to the event, located in Missoula, Montana, saw the object pass directly overhead and heard a double sonic boom. The smoke trail lingered in the atmosphere for several minutes.
A meteor air burst is a type of air burst in which a meteor explodes after entering a planetary body's atmosphere. This fate leads them to be called fireballs or bolides, with the brightest air bursts known as superbolides. Such meteoroids were originally asteroids and comets of a few to several tens of meters in diameter. This separates them from the much smaller and far more common "shooting stars", that usually burn up quickly upon atmospheric entry.
A meteor procession occurs when an Earth-grazing meteor breaks apart, and the fragments travel across the sky in the same path. According to physicist Donald Olson, only four occurrences are known:
On February 9, 1913, a significant meteoric phenomenon was reported from locations across Canada, northeastern United States, Bermuda, and from many ships at sea as far south as Brazil, giving a total recorded ground track of over 11,000 km, and becoming known as the Great Meteor Procession of 1913. The meteors were particularly unusual in that there was no apparent radiant, the point in the sky from which meteors usually appear to originate. The observations were analysed in detail, later the same year, by the astronomer Clarence Chant, leading him to conclude that as all accounts were positioned along a great circle arc, the source had been a small, short-lived natural satellite of the Earth.
An Earth-grazing fireball is a fireball, a very bright meteor that enters Earth’s atmosphere and leaves again. Some fragments may impact Earth as meteorites, if the meteor starts to break up or explodes in mid-air. These phenomena are then called Earth-grazing meteor processions and bolides. Famous examples of Earth-grazers are the 1972 Great Daylight Fireball and the Meteor Procession of July 20, 1860.
Antimatter comets and antimatter meteoroids are hypothetical comets and meteoroids composed solely of antimatter instead of ordinary matter. Although never actually observed, and unlikely to exist anywhere within the Milky Way, they have been hypothesized to exist, and their existence, on the presumption that hypothesis is correct, has been put forward as one possible explanation for various observed natural phenomena over the years.
Comets have been observed by humanity for thousands of years, but only in the past few centuries have they been studied as astronomical phenomena. Before modern times, great comets caused worldwide fear, considered bad omens foreboding disaster and turmoil, for example the 1066 passage of Halley's Comet depicted as heralding the Norman conquest of England. As the science of astronomy developed planetary theories, understanding the nature and composition of comets became a challenging mystery and a large area of study.
John Lockman FRS D.D. (1722–1807) was a Canon of Windsor from 1758 to 1807
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