Taurids
Encyclopedia
The Taurids are an annual meteor shower
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate 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...

 associated with the comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

 Encke
Comet Encke
Comet Encke or Encke's Comet is a periodic comet that completes an orbit of the Sun once every three years — the shortest period of any known comet...

. They are named after their radiant
Radiant (meteor shower)
The radiant or apparent radiant of a meteor shower is the point in the sky, from which meteors appear to originate. The Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus....

 point in the constellation Taurus
Taurus (constellation)
Taurus is one of the constellations of the zodiac. Its name is a Latin word meaning 'bull', and its astrological symbol is a stylized bull's head:...

, where they are seen to come from in the sky. Because of their occurrence in late October and early November, they are also called Halloween
Halloween
Hallowe'en , also known as Halloween or All Hallows' Eve, is a yearly holiday observed around the world on October 31, the night before All Saints' Day...

 fireballs.

Encke and the Taurids are believed to be remnants of a much larger comet, which has disintegrated over the past 20,000 to 30,000 years, breaking into several pieces and releasing material by normal cometary activity or perhaps occasionally by close encounters with the gravitational field
Gravitational field
The gravitational field is a model used in physics to explain the existence of gravity. In its original concept, gravity was a force between point masses...

 of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 or other planets (Whipple, 1940; Klačka, 1999). In total, this stream of matter is the largest in the inner solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

. Due to the stream's size, the Earth takes several weeks to pass through it, causing an extended period of meteor activity, compared with the much smaller periods of activity in other showers. The Taurids are also made up of weightier material, pebble
Pebble
A pebble is a clast of rock with a particle size of 4 to 64 millimetres based on the Krumbein phi scale of sedimentology. Pebbles are generally considered to be larger than granules and smaller than cobbles . A rock made predominantly of pebbles is termed a conglomerate...

s instead of dust
Dust
Dust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...

 grains.

Typically, Taurids appear at a rate of about 7 per hour, moving slowly across the sky at about 17 miles per second (27 kilometers per second), or 65,000 miles per hour. If large enough, these meteors may become bolides, with spectacular light shows and even audible sound.

Due to the gravitational effect of planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

s, especially Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

, the Taurids have spread out over time, allowing separate segments labeled the Northern Taurids and Southern Taurids to become observable. Essentially these are two cross sections of a single, broad, continuous stream in space. The Beta Taurids
Beta Taurids
The Beta Taurids are an annual meteor shower belonging to a class of "daytime showers" that peak after sunrise.The Beta Taurids are normally active from June 5 to July 18. They emanate from an average...

, encountered by the Earth in June/July and which many astronomers consider the cause of the Tunguska event
Tunguska event
The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...

, are also a cross section of the stream. Beta Taurids approach from the Earth's daytime side; so cannot be observed visually in the way the (night-time) Northern and Southern Taurids of October/November can.

The Taurid stream has a cycle of activity that peaks roughly every 2500 to 3000 years, when its core passes nearer to Earth and produces more intense showers. In fact, because of the separate "branches" (night-time in one part of the year and daytime in another; and Northern/Southern in each case) there are two (possibly overlapping) peaks separated by a few centuries, every 3000 years. Some astronomers note that dates for megalith
Megalith
A megalith is a large stone that has been used to construct a structure or monument, either alone or together with other stones. Megalithic describes structures made of such large stones, utilizing an interlocking system without the use of mortar or cement.The word 'megalith' comes from the Ancient...

 structures such as Stonehenge
Stonehenge
Stonehenge is a prehistoric monument located in the English county of Wiltshire, about west of Amesbury and north of Salisbury. One of the most famous sites in the world, Stonehenge is composed of a circular setting of large standing stones set within earthworks...

 are associated with these peaks. The next peak is expected around 3000 AD
Anno Domini
and Before Christ are designations used to label or number years used with the Julian and Gregorian calendars....

.

The Taurids also have more frequent peaks which may result from a heavier concentration of material in the stream, which only hits Earth during some passes.

Some consider the Bronze Age breakup of the originally larger comet to be responsible for ancient destruction
Bronze Age collapse
The Bronze Age collapse is a transition in southwestern Asia and the Eastern Mediterranean from the Late Bronze Age to the Early Iron Age that some historians believe was violent, sudden and culturally disruptive...

 in the Fertile Crescent
Fertile Crescent
The Fertile Crescent, nicknamed "The Cradle of Civilization" for the fact the first civilizations started there, is a crescent-shaped region containing the comparatively moist and fertile land of otherwise arid and semi-arid Western Asia. The term was first used by University of Chicago...

, perhaps evidenced by a large meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

 crater in Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....

. However the Bronze Age was c. 6000 years ago and the original break up of the parent comet, as mentioned above, occurred long before that. Ancient peoples may have been used to Tunguska Class impacts which occur approximately every 300 years as calculated by Eugene Shoemaker and Krakatoa type eruptions both of which have widespread climatic effects and which would dwarf any climatic effects from the slight increase in upper atmospheric dust caused by bolides due to passing through the tail of Comet Encke.

Meteor impact on the Moon

An impact event
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...

 was observed by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 scientist Rob Suggs and astronomer Bill Cooke
Bill Cooke
William Morrill Cooke is a former American football defensive end in the National Football League who played for the Green Bay Packers, the San Francisco 49ers, the Detroit Lions and the Seattle Seahawks...

 while testing out a new 10-in telescope and video camera they had assembled to monitor the moon for meteor strikes http://news.bbc.co.uk/1/hi/sci/tech/4570730.stm. After consulting star chart
Star chart
A star chart is a map of the night sky. Astronomers divide these into grids to use them more easily. They are used to identify and locate astronomical objects such as stars, constellations and galaxies. They have been used for human navigation since time immemorial...

s they concluded that the impact body was probably part of the Taurid meteor shower. This may well be the first recording of this type of lunar
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 event which some have claimed to have witnessed in the past. See http://neo.jpl.nasa.gov/news/news118.html.

Taurids and UFOs

During the week ending November 4, 2005, the large number of fireballs seen all over the world led some to suggest UFO visitations. These fireballs may have been space junk or the Taurids http://www.cnn.com/2005/WORLD/europe/11/04/germany.ufo.reut/index.html.

External links

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