Meteor shower is in the night sky, there are many meteors from the skyRadiant pointEmittedAstronomical phenomenon。These meteors are calledMeteoroidThe debris ofatmosphereStream beam of.Most meteoroids are smaller than gravel, so almost all meteoroids will be destroyed in the atmosphere and will not hit the surface of the earth;The debris that can hit the earth's surface is called meteorite.Meteor showers with a particularly large number or unusual performance will be called "meteor outburst" or“Meteor storm”There may be more than 1000 meteors per hour.[1]
From October 21 to 22, 2018, before sunrise,Orion Meteor ShowerWill usher in great.[2]
The last big meteor shower in 2021 will bloom in the night sky on December 14, and the number of meteors per hour is expected to be up to 150.[14]
International Astronomical UnionEstablish naming rules in 2007[3]The 22nd Committee has confirmed the name of the meteor shower since 2009.The name of the meteor shower will be marked by the constellation closest to the radiation point during the peak period. If necessary, add the bright star of the Greek or Roman alphabet name to mark the name of the meteor shower, and modify the suffix of the Latin all case constellation name or add id or ids to address it,[4]For example, id is used for complex sourceMeteor group(show group), if there is more than one group of sources, add capital before ComplexRoman numerals1. II.For example: Shepherd-Corona BorealisThe meteor cluster (00332 BCB=Bootid Coronae Borealid Complex) is composed of 321/TCB, 322/LBO, 323/XCB three meteor shower sources;Stern-Sail baseThe first group of meteors (00255 PUV=Puppid Velid I Complex), stern VelaGroup IIMeteor cluster (00039 VEL=Puppid Velid II Complex), ids is a meteor shower for separate sources, such as Perseid meteor shower (00007 PER=Perseids);The meteor shower whose radiant point is close to δ Aries star will be calledAries δ meteor shower（00631 DAT = delta Arietids）。[4]
The names of meteor shower and meteor group cannot be interchanged. Identical constellation names can only belong to one category, not both.The International Astronomical Union has a dedicated task team to track meteors and establish a meteor data center,[5]And name the meteor shower that has been confirmed.As of December 31, 2020, the International Astronomical Union has divided meteors into 24 meteor groups, 112 confirmed meteor showers, one pending meteor shower, 722 ordinary meteor showers, and a total of 835 named meteor showers.In addition, there are 157 meteor showers that once appeared but have now been removed from the list due to various reasons.[4]
Radiant point
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Because the path of the particles in the meteor shower in the sky is parallel and the speed is the sameObserverIt seems that they are all the same from the skyPoint radiationThis point is called meteorRadiant point。The generation of radiation points is similar to that of rails on the pathhorizonThe upper vanishing point will be gathered together, which is a perspective effect on the pattern.The meteor shower is always named after the constellation where the radiation point is located. This point is not a fixed point in the sky, but will gradually move on the night sky. Since the earth also rotates around the axis, the stars in the sky will also gradually move (rising in the east and disappearing in the west every day).The radiation points will also move slightly between the background stars every day (the radiation points drift) due to the earth's revolution around the sun.
The meteor shower willfastigiumClosest to the radiation point, with Greece or RomeLetter NameThe formula is marked by a bright star, andLatinpossessive caseThe suffix of constellation name is changed to id or ids.Therefore,Meteor radiation pointnearAquariusThe meteor shower of δ stars will be called delta Aquarius.International Astronomical UnionA dedicated task working group is responsible for tracking meteor showers, establishing a meteor shower data center, and naming meteor showers that have been confirmed.[6]
Meteor observation method
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Observation of meteors is an interesting thing. For scientists, observation of meteors is of great significance in studying the upper atmosphere of the earth, selecting the motion orbits of artificial satellites, spaceships and other spacecraft, and avoiding the impact of meteors.
Meteor shower observation methods are as follows: visual observation, photographic observation, spectral observation, photoelectric observation, television observation, radar observation, space observation, etc.[15]
Meteor Observation Ideas
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There are several precautions for observing meteor shower:
(1) The larger the observation field of view, the more likely to see more meteors.Therefore, the observation should be conducted in an environment without visual field obstacles on a day that is not a full moon.
(2) When observing meteors, the direction of vision should be fixed within a certain period of time.
(3) If several people observe together, they can each take charge of an area in the sky and make observation records.[15]
Meteors can appear from any place in the sky, and the place with wide vision and far away from urban light pollution should be selected as far as possible for visual counting observation.[16]
Meteor origin
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The meteor shower is the result of the interaction between the debris flow of planets and comets.
The disintegration of comets andsteamThe eruption of[1]Whipple developed cometarydirtySnowball theory: surroundsunlightThe comet ofmethane, ammonia, or otherVolatilesIndividual or mixed combination;Rocks can be as big as dust, or as big as pebbles.Dust particleSize of solid inOrder of magnitudeThey are the most common, and they are more common than the common sand and pebble size particles.When these ice sublimate due to warmth, their evaporation will drag out solids such as dust, sand, and pebbles.Every time a comet approaches the sun in orbit, there will be someIce blanketEvaporation and dumping of some meteoroids.These meteoroids scatter to form a meteoroid stream, namely dust tail, which spreads along the whole comet orbit (very small particles will expand and move away rapidly under the radiation pressure of the sun, which is different from the dust tail of ordinary comets).[6]Question ourShort period cometThe meteor shower is not an active comet evaporated by normal water vapor, but a large number of disintegrated and disintegrated fragments of rare dormant comets.Examples includeQuadrant Meteor ShowerandGemini meteor shower, they are from asteroid 2003 EH1 andPhaethon (Phaethon), formed by fragments generated 500 and 1000 years ago respectively.These fragments tend to quickly form dust, sand and pebbles, and quickly form meteoroid dense streams along the orbit of the comet, and then develop along the orbit of the Earth.[7]
Encyclopedia x Knowledgeable: Illustrated Meteor Shower
Activity cycle
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be locatedcometThe dark clouds of dust particles in orbit are called "meteor swarms".When meteoroid particles are just ejected from the comet, their distribution is relatively regular.becauseMegaplanetsGravitational action, these particles will gradually spread throughoutComet orbit。However, this process is not very clear.Various forms of meteor showers occur when the earth passes through meteoroid clustersPossibleHas.Every year the earth passes through the orbit of many comets.If there are meteoroid particles in the orbit, periodic meteor showers will occur.When onlyMother cometRun toPerihelionThe meteor shower that occurs only whenComet Meteor Shower。This indicates that the meteoroid cluster is still near the comet.Within a period of several hundred yearscometMost of the meteor showers are of this type.[8]
Due to the gravitational perturbation of planets,Long-period cometThe meteoroid group of may be very different from that of the parent comet.Meteor showers may also occur when the mother comet is not at the perihelion, which is called far comet type meteor shower.In order to distinguish meteor showers from different directionsMeteor radiation pointThe constellations in the sky area name the meteor shower.For example, meteor showers occur before and after November 17 every yearRadiant pointIn Leo, it is namedLeonid meteor shower。Other meteor showersEta Aquarids 、Orion Meteor Shower、Perseid meteor showerEtc.Meteor showers are essentially different from occasional meteors.Sometimes only a few meteors appear in an hour, but they all seem to "flow out" from the same radiation point, so they also belong to the category of meteor shower;And sometimes thousands of meteors can burst out in the same radiant point in a very short time, just like people setting off fireworks in festivals.When the number of meteors per hour exceeds 1000, we call it“Meteor storm"。[7]
Evolution of body flow
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stayHPMilos Plavec was the first to provide observation shortly after predicting that the dust particles ran at a very low speed relative to the cometmeteoric dustHe was calculatingMeteoroidOnce you leave the comet, most of you will be in front of or behind the comet after a free and complete orbit.This effect is simpleTrack mechanics- These substances, whether drifting from the front or rear of the comet, only slightly move laterally, because these particles will only make the orbit wider[6]Sometimes in the cometinfraredThese particles are observed in the image (thermal radiation), and the dust trace at this time is the last passageSolar timeScattered inComet orbitWhen dust traces pass through the Earth's orbit, the influence of planetary gravity is much like a gardener spraying water on distant plants with a hose.In most years, dust tracks will not meet with the Earth, but in some years there will be meteor showers on the Earth.This effect occurred in 1995Alpha Meteor Shower of KylinFor the first time[7][9]
In the 1890s,IrelandAstronomer George Johnstone Stoney (1826-1911) and British astronomer Arthur Matthew Weld Downing (1850-1917) first tried to calculate the meteoroid trace inEarth orbitPosition on the.They studied the dust particles ejected by comet 55P/Tempel Tuttle in 1866, which were predicted to increase in 1898 and 1899leoBut the final calculation shows that most of the dust traces are still far away from the Earth's orbit;In GermanyBerlinAdolf Berberich of the Royal Astronomical Computing Agency also got the same result through independent calculation.Although there was noMeteor storm, confirmed the calculation results, but still need more and bettercomputing equipmentTo achieve more reliable predictions.
In 1985,KazanState universityED. Kondrat'eva and EA. Reznikov correctly identified for the first time the dust mass that caused the Leonid meteor storm years in the past.The prediction of the Leonid meteor storm in 1999,Robert McNaught [10]、David Asher, andFinlandEsko Lyytinen was the first Western astronomer to use this method.[11]
Historical records
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Ancient Chinese Records
There were about 180 records of meteor showers in ancient China, including about 9 records of Lyra meteor showers,Perseid meteor showerAbout 12 times,Leonid meteor showerThere were 7 records.These records, for the studyMeteor groupThe evolution of orbits is also important information.
《Bamboo Chronicle》There is a record of "The 15th year of the reign of Emperor Xia, the stars fell like rain in the night".《Master Zuo's Spring and Autumn Annals》Zhongyun“Lu Zhuang DukeSeven years in summer and AprilXin MaoAt night, stars disappear, and stars fall like rain in the night."The seventh year of Duke Zhuang of Lu was 687 B.C. - this is the world'sLyra Meteor ShowerThe earliest record of.Liu in the Southern and Northern DynastiesEmperor Xiaowu of Song Dynasty"In the fifth year of the Ming Dynasty... March, the moon covered the Xuanyuan. There were tens of millions of meteors, long or short, big or small, and they traveled westward until dawn."（《Song Dynasty Book·Chronicles of Astronomy) It was in AD 461.Of course, the so-called "tens of millions" here is not an exact number, but a generic term of "extremely many".
tang xunzong"In May of the second year of the Kaiyuan era, there was a star flowing northwest, like an urn or a bucketarcticThe small ones are innumerable. The stars in the sky will shake until dawn. "（《New Tang Dynasty Book·Astronomical Annals) The second year of Kaiyuan was 714 AD.
MeteoroidWhen it falls to the ground, it becomes a meteorite orMeteorite ironThis fact is also recorded in China.In Records of the Historian - Tianguan Book, there is an explanation that "when a star falls to the earth, the stone will also fall".here we areNorthern Song Dynasty，kuo The falling of a meteorite in 1064 AD was recorded in detail in "Mengxi Bitan Vol. 20":,ChangzhouWhen the sun is bright, the sky is as loud as thunder. It is a big star, almost like the moon, which can be seen in the southeast.Once in a while, there was a shock, moving southwest.Another shock and fallYixingIn the Xu's Garden, the county people can be seen from far and near,flameThe sky shines brightly,... There is only one hole in the horizon as big as a cup, very deep.When you look down, the stars are among them, shining brightly. After a long time, they gradually darken and are still hot.After a long time, I found a round stone more than three feet deep, which was still hot, as big as a fist, with one head slightly sharp, as color as iron, and as heavy as it is. "
Now saved inChengdu University of Geology(renamedChengdu University of Technology）The Sichuan Longchuan meteorite is the oldest meteorite in China.It fell in the Ming Dynasty, and was excavated in the 55th year of Kangxi's reign in the Qing Dynasty (1716 AD), weighing 58.5kg.
Related legends
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one
According to the old western saying“Because when a star falls, there must be a sharesoulMake up for it. When a person dies, his soul will ascend to heaven, and when he ascends to heaven, he will bring your wish to God. "
two
The meteor passes by by chance. Seize the moment to make a wish to the meteor, so that the meteor will pass away with your wish, and then your wish will come true
three
Meteor is a star that has crashed into the atmosphere, which is the "present progressive tense";The starlight in the sky is just the shadow of the ancient stars and the "past tense". Of course, if you wish to make a wish at that time, you should ask a meteor to help you.
Of course, these are unscientific statements under the cognitive limitations of the ancients.
The Leonid meteor shower occurs from November 14 to 21 every year.Generally speaking, the number of meteors is about 10 to 15 per hour, but the Leonid meteor shower will have a peak every 33 to 34 years on average, and the number of meteors can exceed thousands per hour.This phenomenon is related to the period of Comet Tempe Tatler.When a meteor shower occurs, it seems that the meteor will be emitted from a specific point in the sky, which is called "radiant point". Since the radiant point of the Leonid meteor shower is located in the constellation Leo, it is named after it.
GeminiMeteor showers occur from December 13 to 14 every year. The maximum hourly flow can reach 120 stars per hour, and the duration of the maximum flow is relatively long.Gemini meteor showerAsteroid 1983TB，The asteroid was discovered by IRAS satellite in 1983, and scientists judged that it may be "burnt out"cometremains.The radiant point of Gemini meteor shower is located in Gemini, which is a famous meteor shower.
The Perseid Meteor Shower occurs from July 17 to August 24 every year. It is not only abundant, but almost never occurs inStarry sky in summerIt is the most suitable meteor shower for non professional meteor observers. It ranks first among the three periodic meteor showers of the year.Comet Swift Tuttle is the mother of the Perseid Meteor Shower. Before and after the comet passed the perihelion in 1992, the Perseid Meteor Shower shone brightly, with the number of meteors reaching more than 400 per hour.
There are two kinds of Orion meteor shower, and the radiation point isBetelgeuseThe nearby meteor shower usually occurs on October 20 every year;The meteor shower with the radiation point near ν occurs from October 15 to October 30, and the maximum day is October 21. The Orion meteor shower is the latter, which is caused by the famous Halley Comet, which returns every 76 yearssolar systemThe debris scattered in the comet's orbit, due toHalley's CometThe famous Orion Meteor Shower and Aquarius Meteor Shower are formed at two intersection points between the orbit and the Earth orbit.
The Taurus meteor shower occurs from October 25 to November 25 every year. Generally, November 8 is its maximum day. The debris on the orbit of Comet Encke forms the meteor shower. On average, five meteors can be observed every hour during the maximum day and hour. Although its flow is small, its period is stable, so it is also largeAstronomerOne of the favorite objects.
6. Dragon Meteor Shower
The Dragon Meteor Shower occurs from October 6 to 10 every year, and the maximum day is October 8. This meteor shower is one of the three periodic meteor showers throughout the year, and the maximum hourly flow can reach 400.Comet Giacobini Zinner isDragon Meteor ShowerThe origin of.
7. Lyra Meteor Shower
Lyra Meteor ShowerIt usually occurs from April 19 to 23 every year, and usually 22 is the maximum day.This meteor shower is the earliest recorded meteor shower in China, and there are vivid records of its outbreak in 687 BC in the ancient book Spring and Autumn.Comet 1861 IOrbital debrisThe Lyra meteor shower, as one of the three periodic meteor showers throughout the year, also occupies an extremely important position in astronomy.[13]
8. Quadrant Meteor Shower
Quadrant Meteor ShowerIt is the first important astronomical phenomenon at the beginning of 2023.The Quadrant Meteor Shower is of medium speed and high brightness, and there will be very bright firemeteors.Firemeteors will emit brighter light, and the meteor trails are longer and longer than ordinary meteors, which are very ornamental.The active period of the Quadrant Meteor Shower is from December 28 to January 12 of the next year. The peak value is from January 3 to 4, and the hourly zenith flow (ZHR) can reach 110.Unlike other meteor showers, which have a long maximum duration, the peak duration of the Quadrant meteor shower is very short, and the number of meteors will decline "precipitously" after the maximum.[16]
9. Aquarius η meteor shower
Aquarius η meteor showerIts parent comet is the famous Halley's Comet.The Earth will travel to the orbit of Halley's Comet in May and October every year. At that time, the particles "left" by the comet in the orbit will enter the earth's atmosphere, rub with the atmosphere, generate high temperature and emit strong light, thus forming two meteor showers.The meteors in the Aquarius η meteor shower group belong to fast meteors, and there are many bright meteors, many of which have traces.[17]
10. Little Ursa Meteor Shower
Little Ursa Meteor ShowerIt is the last meteor shower in 2022, a small meteor shower that occurs regularly every year, and also a meteor shower closest to the northern celestial pole as the radiation point;The Little Dipper meteor shower has the following characteristics: First, the active time lasts about a week from December 17 to December 26 every year, but most of the flow is concentrated near the window period of the maximum, only a few hours;Second, the flow is not large, and the ZHR is 10, sometimes up to 50;Third, the meteor speed is slow, and there are often particularly bright firemeteors;Fourth, the maximum period is around the winter solstice solar term, and the dark night is long. In addition, the declination of the radiation point is very high, so the observation time is long.[18]
research meaning
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Meteor stormRainyObservational research, forNear earth spaceEnvironmental monitoring, space disaster preventionthe ionosphereCommunication securityAnd in-depth understandingcelestial bodies The interrelationship, origin and evolution are of great practical and theoretical value.To explore the mystery of meteor rainstorm, it is not enough to rely only on the theoretical research of experts. It is necessary to rely on the global professional and amateur observation network for joint observation.Through practice, we believe that long-term observation of meteors can obtain valuable data, and we can understand the impact of meteoroids onsolar systemThe distribution of space provides useful clues for the study of the evolution of the solar system and ensures the safety of space flight.andMeteor trailsIt can be used for noninterferenceRadio communicationIt is of great military significance.The sound, light, heat, electromagnetic and other effects generated by convective stars in the atmosphere can also be studiedEarth's atmosphereThe physical condition of.In the century since the 20th century, there have been several meteor storms, and China has no chance to meet them. However, in the first year of the 21st century, China successfully observed the Leonid meteor storm for the first time, and ushered in the 2004Perseid meteor showerExtremely prosperous, which will promote China's astronomical research and carry out science to the publicEducation for AllIt is of positive significance.Learn about the meteoroids (groups) in the solar system and how human beingsCosmic environmentThe sustainable development of is of great significance.[11]
