|
|
| (One intermediate revision by one other user not shown) |
| Line 1: |
Line 1: |
| [[File:Esquel pallasite partial slice.jpg|thumb|A slice of a [[pallasite]] [[Esquel (meteorite)|meteorite fragment]] of what was once a meteoroid before it collided with Earth, discovered in Argentina; on display at the [[Canadian Museum of Nature]] in [[Ottawa]], Canada.]]
| | Courtroom along with other instances may be complex and pricey. Conference attorneys’ fees and also other legal specifications isn't usually straightforward. The miserable factor is the fact that you've to obtain these fees from your own income. Due to this, it may be difficult to fund legal charges. You would possibly actually select often never to prosecute the perpetrator even if you realize that you are around the proper. Legal insurance in Germany helps you to satisfy these expenses. That is by spending a larger percentage of what is necessary in courtroom.<br><br>Because of expensive character of legal charges, it is good to use for legal insurance in Germany. This type of insurance may make sure that you pursue the prison to the greatest. Despite the fact that you are lawfully declaring reimbursement from an insurance carrier, this legal insurance will allow you to. You shouldn't create a blunder of ignoring this important insurance coverage.<br><br>It is doable though to consider that you don’t need legal insurance. Whilst this could be genuine at the present, as time goes by it might not be. It is because you could have a case to deal with at any given occasion. For instance, if your car hurts anyone while operating, you will must sue the dog owner. So that you can do this, you will require the services of legal counsel. A lawyer will ask you for so as to provide solutions. Since you’ve invested dollars regarding therapy, it is achievable that you don’t have sufficient income to invest in the lawyer. The legal insurance in Germany coverage therefore concerns your relief during this period. Even though you possess funds to cover your attorney, your insurance carrier means that this income is guided to different growth initiatives. Also visit [http://pkv-tarifportal.de/die-wichtigsten-versicherungen-im-ueberblick/die-rechtsschutzversicherung/ Weiterlesen]. |
| A '''meteoroid''' is a small rocky or metallic body travelling through space. Meteoroids are significantly smaller than [[asteroid]]s, and range in size from small grains to 1 meter-wide objects.<ref name="science-meteoroid">{{cite web | url=http://science.yourdictionary.com/meteoroid | publisher=Science Dictionary | title=meteoroid | accessdate= }}</ref><ref name="Rubin2010" /><ref name="universe-36398">{{cite web | url=http://www.universetoday.com/36398/what-is-the-difference-between-asteroids-and-meteorites/ | title=What Is The Difference Between Asteroids and Meteorites | first= Jerry | last=Coffey | date=2009-07-30 | quote=...asteroids are smaller than planets but larger than meteoroids | publisher=Universe Today }}</ref><ref name="freedict-meteoroids">{{cite web | url=http://www.thefreedictionary.com/Meteoroids | publisher=The free dictionary | title=meteoroids }}</ref> Most are fragments from [[comet]]s or [[asteroid]]s, while others are [[impact event|collision impact]] [[space debris|debris]] ejected from bodies such as the [[Moon]] or [[Mars]].<ref>http://education.nationalgeographic.co.uk/education/encyclopedia/meteoroid/?ar_a=1</ref><ref>http://solarsystem.nasa.gov/planets/profile.cfm?Object=Meteors&Display=OverviewLong</ref><ref name="NASA-facts">{{cite web | url=http://www.nasa.gov/mission_pages/asteroids/overview/fastfacts.html | title=Asteroid Fast Facts | publisher=NASA | date= | accessdate= }}</ref><ref name="universe-100075">{{cite web | url=http://www.universetoday.com/100075/infographic-whats-the-difference-between-a-comet-asteroid-and-meteor/ | title=Infographic: What's the Difference Between a Comet, Asteroid and Meteor? | publisher=Universe Today | date=20 February 2013 }}</ref>
| |
| | |
| The visible streak of light from space debris is the result of heat as it enters a planet's [[atmosphere]], and the trail of glowing particles that it sheds in its wake is called a '''meteor''', or colloquially a "shooting star" or "falling star". A series of many meteors appearing seconds or minutes apart, and appearing to originate from the same fixed point in the sky, is called a '''[[meteor shower]]'''. Incoming objects larger than several meters (asteroids or comets) can [[List of meteor air bursts|explode in the air]]. If a meteoroid, [[comet]] or asteroid or a piece thereof withstands [[ablation]] from its [[atmospheric entry]] and impacts with the ground, then it is called a '''[[meteorite]]'''. | |
| | |
| Around 15,000 tonnes of meteoroids, [[micrometeoroids]] and different forms of [[space dust]] enter Earth's atmosphere each year.<ref name="ABC-3396756">{{cite episode | first=Stuart | last=Gary | title=Survey finds not all meteors the same | episodelink= | series=ABC Science | network=ABC | airdate=2011-12-22 | url=http://www.abc.net.au/science/articles/2011/12/22/3396756.htm }}</ref>
| |
| | |
| == Meteoroids ==
| |
| {{See also|Micrometeoroid}}
| |
| | |
| [[Image:Meteoroid meteor meteorite.gif|Animated illustration of different phases as a meteoroid enters the Earth's atmosphere to become visible as a meteor and land as a meteorite|thumb|right]]
| |
| [[File:323213main Petersmeteorites 946-710.jpg|thumb|right|225px|{{mpl|2008 TC|3}} meteorite fragments found on Feb. 28, 2009 in the [[Nubian Desert]], [[Sudan]].]]
| |
| In 1961, the [[International Astronomical Union]] defined a meteoroid as "a solid object moving in interplanetary space, of a size considerably smaller than an [[asteroid]] and considerably larger than an atom".<ref name="IMO-meteoroid" /><ref name="Millman1961" /> In 1995, Beech and Steel, writing in ''[[Quarterly Journal of the Royal Astronomical Society]]'', proposed a new definition where a meteoroid would be between 100 [[Micrometer|µm]] and 10 meters across.<ref name="Steel1995" /> Following the discovery of asteroids below 10 m in size,{{clarify | reason = Since this is simply a matter of *definition*, it makes no sense to say 'meteoroids can't be up to 10m because we found smaller asteroids'.|date=October 2013}} Rubin and Grossman refined the Beech and Steel definition of meteoroid to objects between 10 µm and 1 m in diameter.<ref name="Rubin2010" /> The smallest asteroid ever discovered (based on [[Absolute magnitude#Solar System bodies (H)|absolute magnitude]]) is {{mp|2008 TS|26}} with an absolute magnitude of 33.2,<ref name="smallest-jpl" /> and an estimated size of 1-meter.<ref name="NASA-166" /> Objects smaller than meteoroids are classified as '''[[micrometeoroid]]s''' and '''[[cosmic dust]]'''. The [[Minor Planet Center]] does not use the term "meteoroid".
| |
| | |
| ===Meteoroid composition===
| |
| The composition of meteoroids can be inferred as they pass through the Earth's atmosphere from their trajectories and the light spectra of the resulting meteor. Their effects on radio signals also give information, especially useful for daytime meteors which are otherwise very difficult to observe. From these trajectory measurements, meteoroids have been found to have many different orbits, some clustering in streams (see [[Meteor showers]]) often associated with a parent [[comet]], others apparently sporadic. Debris from meteoroid streams may eventually be scattered into other orbits. The light spectra, combined with trajectory and light curve measurements, have yielded various compositions and densities, ranging from fragile snowball-like objects with density about a quarter that of ice,<ref name="USRA-1183">{{cite web | last=Povenmire | first=Harold | url=http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1183.pdf | format=PDF | title=Physical Dynamics of the Upsilon Pegasid Fireball – European Network 190882A | publisher=Florida Institute of Technology }}</ref> to nickel-iron rich dense rocks. The study of [[Meteorite#Meteorite types|meteorites]] also gives insights into the composition of non-ephemeral meteoroids.
| |
| | |
| ===Meteoroids in the Solar System===
| |
| Meteoroids travel around the Sun in a variety of orbits and at various velocities. The fastest ones move at about 42 kilometers per second through space in the vicinity of Earth's orbit.{{citation needed|date=September 2012}} The Earth travels at about 29.6 kilometers per second. Thus, when meteoroids meet Earth's atmosphere head-on (which only occurs when meteors are in a [[retrograde orbit]] such as the Eta Aquarids, which are associated with the retrograde Halley's Comet), the combined speed may reach about 71 kilometers per second. Meteoroids moving through Earth's orbital space average about 20 km/s.<ref name="NASA-2060">{{cite web |title=Report on Orbital Debris |url=http://hdl.handle.net/2060/19900003319 |work=NASA |publisher=NASA Technical Reports Server |accessdate=1 September 2012 }}</ref>
| |
| | |
| On 2013 January 17 at 05:21 PST a 1 meter-sized comet from the Oort cloud entered Earth atmosphere.<ref name="CAMS" /> The object had a retrograde orbit with perihelion at 0.98 ± 0.03 [[Astronomical unit|AU]]. It approached from the direction of the constellation Virgo, and collided head-on with Earth atmosphere at 72 ± 6 km/s<ref name="CAMS">{{cite web |title=2013 January 17 Sierra Nevada fireball |publisher=[[SETI Institute]] |first=Peter |last=Jenniskens |authorlink=Peter Jenniskens |url=http://cams.seti.org/ |accessdate=2013-01-25 }} | {{cite web | url=http://www.seti.org/seti-institute/news/earth-collides-with-comet | title=Earth Collides Head-On with Small Comet | publisher=[[SETI Institute]] | date= | accessdate= }}</ref> vapourising more than 100 km above ground over a period of several seconds.
| |
| | |
| ===Meteoroid collisions with Earth and its atmosphere===
| |
| When meteoroids intersect with the Earth's atmosphere at night, they are likely to become visible as '''meteors'''. If meteoroids survive the entry through the atmosphere and reach the Earth's surface, they are called '''meteorites'''. Meteorites are transformed in structure and chemistry by the heat of entry and force of impact. A noted meteoroid, {{mpl|2008 TC|3}}, was observed in space on a collision course with Earth on 6 October 2008 and entered the Earth's atmosphere the next day, striking a remote area of northern Sudan. It was the first time that a meteoroid had been observed in space and tracked prior to impacting Earth.
| |
| | |
| Note: the International Astronomical Union (IAU) defines a "meteoroid" as moving through interplanetary space. The IAU, knowing that a "meteoroid falling through the Earth's atmosphere" is no longer orbiting the Sun, has defined a "meteor" as being the extraterrestrial object, as well as, the "visible streak of light" that it produced. The relegating of the term "meteor" to being only the "visible streak of light" is a common misuse of the terms "meteoroid" and "meteor" as originally defined by the IAU.<ref name="Verish">{{cite web
| |
| |title=From Asteroids to Meteoroids to Meteors to Meteorites
| |
| |last=Verish |first=Robert
| |
| |url=http://meteorite-recovery.tripod.com/2008/mar08.htm
| |
| |accessdate=2014-01-05}}</ref>
| |
| | |
| ==Meteor==
| |
| [[File:Leonid Meteor.jpg|thumb|A [[Leonids|Leonid]] meteor, seen in the 2009 Leonid Meteor Shower.]]
| |
| :''"Meteor" and "Meteors" redirect here. For other uses, see [[Meteor (disambiguation)]].''
| |
| [[File:Meteor burst.jpg|thumb|Photo of a part of the sky during a [[meteor shower]] over an extended [[exposure time]]. The meteors have actually occurred several seconds to several minutes apart.]]
| |
| | |
| {{see also|List of meteor air bursts}}
| |
| | |
| A '''meteor''' or "shooting star" is the visible streak of light from a meteoroid or [[micrometeoroid]], heated and glowing from entering the Earth's atmosphere, as it sheds glowing material in its wake. Meteors typically occur in the [[mesosphere]] at altitudes between 76 km to 100 km (46–62 miles).<ref name="MIT-pje">{{cite web |url=http://www.haystack.mit.edu/~pje/meteors/ |title=Millstone Hill UHF Meteor Observations: Preliminary Results |first=Philip J. |last=Erickson |date= |accessdate= }}</ref> The root word ''meteor'' comes from the [[Ancient Greek|Greek]] ''meteōros'', meaning "suspended in the air".
| |
| | |
| Millions of meteors occur in the Earth's atmosphere daily. Most meteoroids that cause meteors are about the size of a [[pebble]]. Meteors may occur in [[meteor shower|showers]], which arise when the Earth passes through a stream of debris left by a comet, or as "random" or "sporadic" meteors, not associated with a specific stream of space debris. A number of specific meteors have been observed, largely by members of the public and largely by accident, but with enough detail that orbits of the meteoroids producing the meteors have been calculated. All of the orbits passed through the [[asteroid belt]].<ref name="UR-mb5">{{cite web |url=http://uregina.ca/~astro/mb_5.html |title=Diagram 2: the orbit of the Peekskill meteorite along with the orbits derived for several other meteorite falls |publisher=Uregina.ca |accessdate=2011-09-16 }}</ref> The atmospheric velocities of meteors result from the movement of Earth around the Sun at about 30 km/s (18 miles/second),<ref name="NASA-earthfact">{{cite web |last=Williams |first=David R. |date=2004-09-01 |url=http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html |title=Earth Fact Sheet |publisher=NASA |accessdate=2010-08-09 }}</ref> the orbital speeds of meteoroids, and the [[gravity well]] of Earth.
| |
| | |
| Meteors become visible between about 75 to 120 km (34–70 miles) above the Earth. They usually disintegrate at altitudes of 50 to 95 km (31–51 miles).<ref name=meteorsandtheirparentcomets /> Meteors have roughly a fifty percent chance of a daylight (or near daylight) collision with the Earth. Most meteors are, however, observed at night, when darkness allows fainter objects to be recognised. For bodies with a size scale larger than <!--the atmospheric [[mean free path]] -->(10 cm to several meters)<!--{{Clarify|date=February 2009}}--><!-- see talk page --> meteor visibility is due to the atmospheric [[ram pressure]] (not friction) that heats the meteoroid so that it glows and creates a shining trail of gases and melted meteoroid particles. The gases include vaporized meteoroid material and atmospheric gases that heat up when the meteoroid passes through the atmosphere. Most meteors glow for about a second. A relatively small percentage of meteoroids hit the Earth's atmosphere and then pass out again: these are termed [[Earth-grazing fireballs]] (for example [[The Great Daylight 1972 Fireball#All known Earth-grazing fireballs|The Great Daylight 1972 Fireball]]). The visible light produced by a meteor may take on various hues, depending on the chemical composition of the meteoroid, and the speed of its movement through the atmosphere. As layers of the meteoroid abrade and ionize, the color of the light emitted may change according to the layering of minerals. Possible colors (and elements producing them) include:
| |
| * Orange/yellow (sodium)
| |
| * Yellow (iron)
| |
| * Blue/green (copper)
| |
| * Purple (potassium)
| |
| * Red (silicate)
| |
| (The above statement needs a reference, and does not take into account the color produced by the ionization of the gas molecules in the atmosphere, or the red-hue of meteors closer to the horizon.)
| |
| ===Fireball===
| |
| [[File:Fireball geminids 2010-12-09 01-10ut.gif|thumbnail|Fireball (bolide) Geminids -3 mag in [[Special Astrophysical Observatory of the Russian Academy of Science]]]]
| |
| {{see also|List of meteor air bursts}}
| |
| {| class=wikitable style="text-align:center; font-size:11px; float:right; margin:2px"
| |
| |- bgcolor= style="font-size
| |
| | colspan="8" style="text-align:center;"|'''Reported Fireballs'''<ref name="AMS-Fireballs">{{cite web |title=Fireball Logs |url=http://www.amsmeteors.org/fireballs/fireball-report/ |accessdate=2013-03-18}}</ref>
| |
| |-
| |
| ! Year !! #
| |
| |-
| |
| | 2013 || 3556
| |
| |-
| |
| | 2012 || 2326
| |
| |-
| |
| | 2011 || 1629
| |
| |-
| |
| | 2010 || 948
| |
| |-
| |
| | 2009 || 692
| |
| |-
| |
| | 2008 || 726
| |
| |}
| |
| | |
| A '''fireball''' is a brighter-than-usual meteor. The [[International Astronomical Union]] defines a fireball as "a meteor brighter than any of the planets" ([[Apparent magnitude|magnitude]] −4 or greater).<ref name="meteor-13871">{{cite web |url=http://www.meteorobs.org/maillist/msg13871.html |title=MeteorObs Explanations and Definitions (states IAU definition of a fireball) |publisher=Meteorobs.org |date=1999-07-09 |accessdate=2011-09-16 }}</ref> The [[International Meteor Organization]] (an amateur organization that studies meteors) has a more rigid definition. It defines a fireball as a meteor that would have a magnitude of −3 or brighter if seen at [[zenith]]. This definition corrects for the greater distance between an observer and a meteor near the horizon. For example, a meteor of magnitude −1 at 5 degrees above the horizon would be classified as a fireball because if the observer had been directly below the meteor it would have appeared as magnitude −6.<ref name="IMO-fireball">{{cite web |url=http://www.imo.net/fireball |title=International Meteor Organization - Fireball Observations |publisher=imo.net |date=2004-10-12 |accessdate=2011-09-16 }}</ref> For 2013 there were 3556 fireballs recorded at the [[American Meteor Society]].<ref name="Fireballs2013">{{cite web |title=Fireball Report: 3556 Events found in 2013 |publisher=[[American Meteor Society]] |url=http://www.amsmeteors.org/fireball_event/2013/ |accessdate=2014-01-14}}</ref> There are probably more than 500,000 fireballs a year,<ref name="AMS-FAQ">{{cite web |title=Fireball FAQs |publisher=[[American Meteor Society]] |url=http://www.amsmeteors.org/fireballs/faqf/ |accessdate=2013-03-21}}</ref> but most will go unnoticed because most will occur over the ocean and half will occur during the daytime.
| |
| | |
| Fireballs reaching [[Apparent magnitude|magnitude]] −14 or brighter are called '''bolides'''.<ref name="Belton">{{cite book | last=Di Martino | first=Mario | last2=Cellino | first2=Alberto | chapter=Physical properties of comets and asteroids inferred from fireball observations | title=Mitigation of hazardous comets and asteroids | publisher=Cambridge University Press | year=2004 | page=156 | url=http://books.google.ca/books?id=Dw0A7T0fy6AC&pg=PA156 | isbn=0-521-82764-7 | editor-last=Belton | editor1-first=Michael J. S. | editor2-last=Morgan | editor2-first=Thomas H. | editor3-last=Samarasinha | editor3-first=Nalin | editor4-last=Yeomans | editor4-first=Donald K. }}</ref> The IAU has no official definition of "bolide", and generally considers the term synonymous with "fireball". Astronomers often use "bolide" to identify an exceptionally bright fireball, particularly one that explodes (sometimes called a detonating fireball). It may also be used to mean a fireball which creates audible sounds. In the late twentieth century, bolide has also come to mean any object that hits the Earth and explodes, with no regard to its composition (asteroid or comet).<ref name="Google-Book-jR84AAAAIAAJ">{{cite book | last=Rogers | first=John J. W. | url=http://books.google.ca/books?id=jR84AAAAIAAJ&pg=PA251 | title=A History of the Earth | publisher=Cambridge University Press | year=1993 | page=251 }}</ref> The word ''bolide'' comes from the [[Greek language|Greek]] βολίς (''bolis'') <ref name="myet-bolide">{{cite web | url=http://www.myetymology.com/english/bolide.html | publisher=MyEymology | title=Bolide | accessdate= }}</ref> which can mean ''a missile'' or ''to flash''.<!-- ====Superbolide==== Links from [[Sulawesi 2009 superbolide]] via [[Superbolide]] --> If the [[Apparent magnitude|magnitude]] of a bolide reaches −17 or brighter it is known as a '''superbolide'''.<ref name="Belton" /><ref name="Google-Book-3Hd8Lw1hExUC">{{cite book | last=Adushkin | first=Vitaly | last2=Nemchinov | first2=Ivan | title=Catastrophic events caused by cosmic objects | publisher=Springer | year=2008 | page=133 | url=http://books.google.com/?id=3Hd8Lw1hExUC | isbn=1-4020-6451-9}}</ref>
| |
| | |
| ===Atmospheric remains of meteor passage===
| |
| Entry of meteoroids into the Earth's atmosphere produces three main effects: ionization of atmospheric molecules, dust that the meteoroid sheds, and the sound of passage.
| |
| | |
| During the entry of a meteoroid or asteroid into the [[upper atmosphere]], an '''ionization trail''' is created, where the molecules in the upper atmosphere are [[ionization|ionized]] by the passage of the meteor. Such ionization trails can last up to 45 minutes at a time. Small, [[sand-grain]] sized meteoroids are entering the atmosphere constantly, essentially every few seconds in any given region of the atmosphere, and thus ionization trails can be found in the upper atmosphere more or less continuously. When radio waves are bounced off these trails, it is called [[meteor burst communications]]. Meteor radars can measure atmospheric density and winds by measuring the [[decay rate]] and [[Doppler shift]] of a meteor trail. Most meteoroids burn up when they enter the atmosphere. The left-over debris is called '''meteoric dust''' or just meteor dust. Meteor dust particles can persist in the atmosphere for up to several months. These particles might affect climate, both by scattering electromagnetic radiation and by catalyzing chemical reactions in the upper atmosphere.<ref name="Nature-443141a">{{cite web |first=Jeff |last=Kanipe |title=Climate change: A cosmic connection |url=http://www.nature.com/nature/journal/v443/n7108/full/443141a.html |publisher=[[Nature (journal)]] |date=14 September 2006 |accessdate=2009-05-05 }}</ref> Larger meteors can enter '''dark flight''' after deceleration where the meteorite (or fragments) fall at [[terminal velocity]].<ref name="IMO-meteorites" /> Dark flight starts when the meteorite(s) decelerate to about {{convert|2|–|4|km/s|mph|abbr=on}}.<ref name="AMS-Fireball" /> Larger fragments will fall further down the [[strewn field]].
| |
| | |
| ====Sounds of meteors====
| |
| Sound generated by a meteor in the upper atmosphere, such as a [[sonic boom]], typically arrives many seconds after the visual light from a meteor disappears. Occasionally, as with the [[Leonid meteor shower]] of 2001,"crackling", "swishing", or "hissing" sounds have been reported,<ref name="find-87854873">{{cite news |url=http://findarticles.com/p/articles/mi_m1134/is_6_111/ai_87854873/pg_1 |work=Natural History |title=Psst! Sounds like a meteor: in the debate about whether or not meteors make noise, skeptics have had the upper hand until now |first=Alan |last=Burdick |year=2002 }}</ref> occurring at the same instant as a meteor flare. Similar sounds have also been reported during intense displays of Earth's [[Aurora (astronomy)|auroras]].<ref name="auroral-sounds">{{cite web |url=https://sites.google.com/site/auroralsound/ |first=Andris |last=Vaivads |year=2002 |title=Auroral Sounds |accessdate=2011-02-27 }}</ref><ref name="auroral-acoustics">{{cite web |url=http://www.acoustics.hut.fi/projects/aurora/ |title=Auroral Acoustics |work=Laboratory of Acoustics and Audio Signal Processing, Helsinki University of Technology |accessdate=2011-02-17 }}</ref><ref name="AG16-155">{{cite journal |doi=10.1016/S0065-2687(08)60352-0 |first=Sam M. |last=Silverman |first2=Tai-Fu |last2=Tuan |year=1973 |title=Auroral Audibility |journal=Advances in Geophysics |volume=16 |pages=155–259 |series=Advances in Geophysics |isbn=9780120188161 |bibcode = 1973AdGeo..16..155S }}</ref><ref name="JRASC-373K">{{cite journal |first=Colin S. L. |last=Keay |year=1990 |title=C. A. Chant and the Mystery of Auroral Sounds |journal=Journal of the Royal Astronomical Society of Canada |volume=84 |pages=373–382 |url=http://articles.adsabs.harvard.edu/full/1990JRASC..84..373K |bibcode=1990JRASc.84..373K }}</ref>
| |
| | |
| Sound recordings made under controlled conditions in Mongolia in 1998 support the contention that the sounds are real.<ref name="BBC-321596">{{cite web |url=http://news.bbc.co.uk/2/hi/science/nature/321596.stm |title=Sound of shooting stars |publisher=BBC News |date=1999-04-21 |accessdate=2011-09-16 }}</ref>
| |
| | |
| Theories on the generation of these sounds may partially explain them. For example, scientists at [[NASA]] suggested that the turbulent ionized wake of a meteor interacts with the magnetic field of the Earth, generating pulses of radio waves. As the trail dissipates, [[megawatt]]s of electromagnetic energy could be released, with a peak in the [[power spectrum]] at [[audio frequency|audio frequencies]]. Physical vibrations induced by the electromagnetic impulses would then be heard if they are powerful enough to make grasses, plants, eyeglass frames, and other conductive materials vibrate.<ref name="NASA-ast26">{{cite web |url=http://science.nasa.gov/headlines/y2001/ast26nov_1.htm |title=Listening to Leonids |publisher=science.nasa.gov |accessdate=2011-09-16 }}</ref><ref name="Dawes-extract">{{cite web |url=http://homepages.tesco.net/~John.Dawes2/extract.htm |title=Hearing Sensations in Electric Fields |last=Dawes |first=John |accessdate=2011-09-16 }}</ref><ref name="Dawes-frey">{{cite web |url=http://homepages.tesco.net/~John.Dawes2/frey.htm |title=Human auditory system response to Modulated electromagnetic energy |last=Dawes |first=John |accessdate=2011-09-16 }}</ref><ref name="Dawes-frey2">{{cite web |url=http://homepages.tesco.net/~John.Dawes2/frey2.htm |title=Human Perception of Illumination with Pulsed Ultrahigh-Frequency Electromagnetic Energy |last=Dawes |first=John |accessdate=2011-09-16 }}</ref> This proposed mechanism, although proven to be plausible by laboratory work, remains unsupported by corresponding measurements in the field.
| |
| | |
| === Seasonal variation in meteor sightings ===
| |
| {{see also|List of meteor showers}}
| |
| A [[meteor shower]] is the result of an interaction between a planet, such as Earth, and streams of debris from a [[comet]] or other source. The passage of the Earth through cosmic debris from comets and other sources is a [[List of meteor showers|recurring event]] in many cases. Comets can produce debris by water vapor drag, as demonstrated by [[Fred Whipple]] in 1951,<ref name="Harvard-464W">{{cite web | authorlink=Fred Lawrence Whipple | year=1951 | url=http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1951ApJ...113..464W&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf | format=PDF | title=A Comet Model. II. Physical Relations for Comets and Meteors | journal=Astrophysical Journal | volume=113 | pages=464–474 }}</ref> and by breakup. Each time a comet swings by the Sun in its [[orbit]], some of its ice vaporizes and a certain amount of meteoroids will be shed. The meteoroids spread out along the entire orbit of the comet to form a meteoroid stream, also known as a "dust trail" (as opposed to a comet's "dust tail" caused by the very small particles that are quickly blown away by solar radiation pressure).
| |
| | |
| The frequency of [[Meteoroid#Fireball|fireball]] sightings increases by about 10-30% during the weeks of [[Equinox|vernal equinox]].<ref name="fireball season NASA">{{cite web |first=Tony |last=Phillips |url=http://science.nasa.gov/science-news/science-at-nasa/2011/31mar_springfireballs/ |title=Spring is Fireball Season |publisher=science.nasa.gov |accessdate=2011-09-16 }}</ref> Even [[meteorite]] falls are more common during the northern hemisphere's spring season. Although this phenomenon has been known for quite some time, the reason behind the anomaly is not fully understood by scientists. Some researchers attribute this to an intrinsic variation in the meteoroid population along Earth's orbit, with a peak in big fireball-producing debris around spring and early summer. Research is in progress for mapping the orbits of the meteors in order to gain a better understanding of the phenomenon.<ref name="camera network NASA">{{cite web |first=Dauna |last=Coulter |url=http://science.nasa.gov/science-news/science-at-nasa/2011/01mar_meteornetwork/ |title=What's Hitting Earth? |publisher=science.nasa.gov |date=2011-03-01 |accessdate=2011-09-16 }}</ref>
| |
| | |
| ===History===
| |
| Although meteors have been known since ancient times, they were not known to be an astronomical phenomenon until early in the 19th century. Prior to that, they were seen in the West as an atmospheric phenomenon, like lightning, and were not connected with strange stories of rocks falling from the sky. [[Thomas Jefferson]] wrote "I would more easily believe that (a) Yankee professor would lie than that stones would fall from heaven."<ref name="jefferson">{{cite web | last=Taibi | first=Richard | url=http://www.amsmeteors.org/about/ams-history/the-early-years-of-meteor-observations-in-the-usa/ | title=The Early Years of Meteor Observations in the USA | publisher=American Meteor Society | accessdate=}}</ref> He was referring to [[Yale]] chemistry professor [[Benjamin Silliman]]'s investigation of an 1807 meteorite that fell in [[Weston meteorite|Weston, Connecticut]].<ref name="jefferson" /> Silliman believed the meteor had a cosmic origin, but meteors did not attract much attention from astronomers until the spectacular meteor storm of November 1833.<ref name="1833leonids">{{cite web | url=http://meteorshowersonline.com/showers/leonidhis.html | publisher=Meteorshowers Online | title=The Leonids and the Birth of Meteor Astronomy | date= | accessdate= }}</ref> People all across the eastern United States saw thousands of meteors, radiating from a single point in the sky. Astute observers noticed that [[Radiant (meteor shower)|the radiant]], as the point is now called, moved with the stars, staying in the constellation Leo.<ref name="AJSA-1834">{{cite journal | url=http://books.google.com/?id=HjcPAAAAYAAJ&pg=PA407#PPA405,M1 | journal=The American Journal of Science and Arts | volume=XXV | date=January 1834 | title=On the Meteors of Nov. 13, 1833 | first=Edward | last=Hitchcock }}</ref>
| |
| | |
| The astronomer [[Denison Olmsted]] made an extensive study of this storm, and concluded it had a cosmic origin. After reviewing historical records, [[Heinrich Wilhelm Matthias Olbers]] predicted the storm's return in 1867, which drew the attention of other astronomers to the phenomenon. [[Hubert Anson Newton|Hubert A. Newton]]'s more thorough historical work led to a refined prediction of 1866, which proved to be correct.<ref name="1833leonids" /> With [[Giovanni Schiaparelli]]'s success in connecting the [[Leonids]] (as they are now called) with comet [[Tempel-Tuttle]], the cosmic origin of meteors was now firmly established. Still, they remain an atmospheric phenomenon, and retain their name "meteor" from the Greek word for "atmospheric".<ref name="AP-318">{{cite web | url=http://astroprofspage.com/archives/318 | publisher=Astro Prof | title=October's Orionid Meteors | author= | date= | accessdate= }}</ref>
| |
| | |
| ====Notable meteors====
| |
| {{See also|Near-Earth object#Historic impacts}}
| |
| <!-- formerly linked to #Planet Earth collision probability with near-Earth objects|l1=Planet Earth collision probability with near-Earth objects}}-->
| |
| | |
| =====1992—Peekskill, New York=====
| |
| The [[Peekskill Meteorite]] was filmed on October 9, 1992 by at least 16 independent videographers.<ref name="uwo-peeks">{{cite web | url=http://aquarid.physics.uwo.ca/~pbrown/Videos/peekskill.htm | title=The Peekskill Meteorite 9 October 1992 Videos | publisher= | date= | accessdate= }}</ref> Eyewitness accounts indicate the fireball entry of the Peekskill meteorite started over West Virginia at 23:48 UT (±1 min). The fireball, which traveled in a northeasterly direction, had a pronounced greenish colour, and attained an estimated peak visual magnitude of −13. During a luminous flight time that exceeded 40 seconds the fireball covered a ground path of some 700 to 800 km.<ref name="Nature-6464">{{cite journal | last1=Brown | first1=Peter | last2=Ceplecha | first2=Zedenek | last3=Hawkes | first3=Robert L. | last4=Wetherill | first4=George W | last5=Beech | first5=Martin | last6=Mossman | first6=Kaspar | url=http://cdsads.u-strasbg.fr/cgi-bin/bib_query?1994Natur.367..624B | title=The orbit and atmospheric trajectory of the Peekskill meteorite from video records | journal=Nature | volume=367 | issue=6464 | pages=624–626 | year=1994 |bibcode = 1994Natur.367..624B |doi = 10.1038/367624a0 }}</ref> One meteorite recovered at [[Peekskill, New York]], for which the event and object gained their name, had a mass of 12.4 kg (27 lb) and was subsequently identified as an H6 monomict breccia meteorite.<ref name="MB-75">{{cite journal | last=Wlotzka | first=Frank | journal=Meteoritical Bulletin #75 | title=Meteoritics | volume=28 | issue=5 | page=692 | year=1994 }}</ref> The video record suggests that the Peekskill meteorite had several companions over a wide area. The companions are unlikely to be recovered in the hilly, wooded terrain in the vicinity of Peekskill.
| |
| | |
| =====2009—Bone, Indonesia=====
| |
| A large fireball was observed in the skies near Bone, Indonesia on October 8, 2009. This was thought to be caused by an asteroid approximately 10 meters in diameter. The fireball contained an estimated energy of 50 kilotons of TNT, or about twice the [[Fat Man|Nagasaki atomic bomb]]. No injuries were reported.<ref name="NEO165">{{cite web |date=October 23, 2009 |title=Asteroid Impactor Reported over Indonesia |publisher=NASA/JPL Near-Earth Object Program Office |first=Donald K. |last=Yeomans |first2=Paul |last2=Chodas |first3=Steve |last3=Chesley |url=http://neo.jpl.nasa.gov/news/news165.html |accessdate=2009-10-30 }}</ref>
| |
| | |
| =====2009—Southwestern US=====
| |
| A large bolide was reported on 18 November 2009 over southeastern California, northern Arizona, Utah, Wyoming, Idaho and Colorado. At 00:07 local time a security camera at the high altitude W. L. Eccles Observatory (2930 m above sea level) recorded a movie of the passage of the object to the north.<ref name="YT-XiL1UGbHXSI">{{cite web |url=http://www.youtube.com/watch?v=XiL1UGbHXSI |title=W. L. Eccles Observatory, November 18, 2009, North Camera |publisher=YouTube |date=2009-11-18 |accessdate=2011-09-16 }}</ref><ref name="YT-kE109bKQESw">{{cite web |url=http://www.youtube.com/watch?v=kE109bKQESw |title=W. L. Eccles Observatory, November 18, 2009, North West Camera |publisher=YouTube |date=2009-11-18 |accessdate=2011-09-16 }}</ref> Of particular note in this video is the spherical "ghost" image slightly trailing the main object (this is likely a lens reflection of the intense fireball), and the bright fireball explosion associated with the breakup of a substantial fraction of the object. An object trail can be seen to continue northward after the bright fireball event. The shock from the final breakup triggered seven seismological stations in northern Utah; a timing fit to the seismic data yielded a terminal location of the object at 40.286 N, -113.191 W, altitude 27 km.<ref>Wiggins, Patrick; private communication</ref> This is above the Dugway Proving Grounds, a closed Army testing base.
| |
| | |
| =====2013—Chelyabinsk Oblast, Russia=====
| |
| {{main|Chelyabinsk meteor}}
| |
| Over 1,500 people were injured mostly by glass from shattered windows caused by a meteoroid explosion during [[2013 Russian meteor event|meteor event in Chelyabinsk Oblast]], Russia on 15 February 2013, when a meteoroid exploded approx 25 to 30 km above the [[Chelyabinsk Oblast|environs of Chelyabinsk]], [[Russia]]. An increasingly bright streak was observed during morning daylight with a large contrail lingering behind. At no less than 1 minute and up to at least 3 minutes after the object peaked in intensity (depending on distance from trail), a large concussive blast was heard that shattered windows and set-off car alarms, which was followed by a number of smaller explosions.<ref name="guardian-20130215">{{cite web |title=Meteorite slams into Central Russia injuring 1100 - as it happened |url=http://www.guardian.co.uk/science/2013/feb/15/meteorite-explodes-over-russian-urals-live-updates |publisher=Guardian |date=15 February 2013 |accessdate=16 February 2013}}</ref> Scientists at [[NASA]]'s [[Jet Propulsion Laboratory]] (JPL) estimated the meteoroid to have an initial mass of 11,000 tonnes, and to measure approximately 17 to 20 metres across, as it entered the earth's atmosphere.<ref name="JPL20130301">{{cite web |date=1 March 2013 |title=Additional Details on the Large Fireball Event over Russia on Feb. 15, 2013 |publisher=NASA/JPL Near-Earth Object Program Office |first1=Don |last1=Yeomans |first2=Paul |last2=Chodas |url=http://neo.jpl.nasa.gov/news/fireball_130301.html |accessdate=2 March 2013}}</ref><ref name="NASA-061">{{cite web | url=http://www.jpl.nasa.gov/news/news.php?release=2013-061 | author=JPL | title=Russia Meteor Not Linked to Asteroid Flyby | date=2012-02-16 | accessdate=2013-02-19}}</ref>
| |
| | |
| ===Gallery of meteors===
| |
| <center><Gallery style="margin:auto;">
| |
| Image:Orionid, pedia.org/wiki/Milky_way Milky Way] and to the right of [[Venus]]. [[Zodiacal light]] is also seen in the image.
| |
| Image:Orionid meteor.jpg|[[Orionids|Orionid]]
| |
| Image:Orionid meteor1.jpg|[[Orionids|Orionid]]
| |
| Image:Two orionids and milky way.jpg|Two Orionids and [[Milky Way]]
| |
| Image:Multi colored Orionid.jpg|Multi-colored Orionid
| |
| Image:Orionids and Orion.jpg|Orionid
| |
| Image:Meteor trail.jpg|The brightest meteor, a fireball, leaves a smoky, persistent trail drifting in high-altitude winds, which is seen at the right-hand side of the image left by [[Orionids|Orionid]].
| |
| Image:Leonid Meteor.jpg|A photograph of a [[Leonids]] meteor showing a meteor, its afterglow, and its wake
| |
| Image:Meteor Bolide.JPG|A fireball seen over the desert of Central Australia. Although this occurred during the [[Lyrids]], its North-East entry angle indicates it is sporadic.
| |
| Image:Looking Down on a Shooting Star.JPG|Looking down from the International Space Station at a meteor as it passes through the atmosphere
| |
| Image:Earth Sol63A UFO-A067R1.jpg|First meteor photographed from Mars, March 7, 2004, by [[Spirit rover|MER ''Spirit'']]
| |
| Image:SL9ImpactGalileo.jpg|A sequence of [[Galileo spacecraft|Galileo]] images, taken several seconds apart, showing the appearance of the fireball of fragment W on the dark side of Jupiter
| |
| </gallery></center>
| |
| | |
| ==Meteorite and meteoroid impacts==
| |
| {{Main|Meteorite}}
| |
| A '''meteorite''' is a portion of a meteoroid or asteroid that survives its passage through the atmosphere and hits the ground without being destroyed.<ref name="oxford">The Oxford Illustrated Dictionary. 1976. Second Edition. Oxford University Press. page 533</ref> Meteorites are sometimes, but not always, found in association with hypervelocity [[impact crater]]s; during energetic collisions, the entire impactor may be vaporized, leaving no meteorites. [[Geologist]]s use the term, "bolide", in a different sense from [[astronomer]]s to indicate a very large [[impact event|impactor]]. For example, the [[United States Geological Survey|USGS]] uses the term to mean a generic large crater-forming projectile in a manner "to imply that we do not know the precise nature of the impacting body ... whether it is a rocky or metallic asteroid, or an icy comet for example".<ref name="USGS-bolide">{{cite web |url=http://woodshole.er.usgs.gov/epubs/bolide/introduction.html |title=What is a Bolide? |publisher=woodshole.er.usgs.gov |accessdate=2011-09-16 }}</ref>
| |
| | |
| Meteoroids also hit other bodies in the solar system. On such stony bodies as the [[moon]] or [[Mars]] with no or little atmosphere, they leave enduring craters.
| |
| | |
| ===Frequency of large meteoroid collisions with Earth===
| |
| {{See also|Near-Earth object#Planet Earth collision probability with near-Earth objects|l1=Planet Earth collision probability with near-Earth objects}}
| |
| The diameter of the biggest impactor to hit Earth on any given day is likely to be about 40 centimeters, in a given year about 4 meters, and in a given century about 20 meters. These statistics are obtained by the following:
| |
| | |
| Over at least the range from 5 centimeters (2 inches) to roughly 300 meters (1,000 feet), the rate at which Earth receives meteors obeys a [[power law|power-law]] distribution as follows:
| |
| | |
| :<math>N(>D) = 37 D^{-2.7}\ </math>
| |
| | |
| where ''N'' (>''D'') is the expected number of objects larger than a diameter of ''D'' meters to hit Earth in a year.<ref name="Nature-01238">{{cite web |first=Peter |last=Brown |first2=Richard E. |last2=Spalding |first3=Douglas O. |last3=ReVelle |first4=Edward |last4=Tagliaferri |first5=Simon P. |last5=Worden |title=The flux of small near-Earth objects colliding with the Earth |url=http://www.nature.com/nature/journal/v420/n6913/full/nature01238.html |publisher=[[Nature (journal)]] |date=21 September 2002 |accessdate=2009-06-22 }}</ref> This is based on observations of bright meteors seen from the ground and space, combined with surveys of [[Near Earth Asteroids|near Earth asteroids]]. Above 300 meters in diameter, the predicted rate is somewhat higher, with a two-kilometer asteroid (one million-[[megatons|megaton]] TNT equivalent) every couple of million years — about 10 times as often as the power-law extrapolation would predict.
| |
| <!-- ===Bolide=== This section is linked from [[Eocene]] -->
| |
| | |
| ===Meteorite and meteoroid impact craters===
| |
| {{Main|Impact crater}}
| |
| | |
| [[File:Two tektites.JPG|thumb|Two tektites, molten terrestrial ejecta from a meteorite impact.]]
| |
| Meteoroid collisions with solid Solar System objects, including the [[Moon]], [[mercury (planet)|Mercury]], [[Callisto (moon)|Callisto]], [[Ganymede (moon)|Ganymede]] and most small moons and [[asteroid]]s, create impact craters, which are the dominant geographic features of many of those objects. On other planets and moons with active surface geological processes, such as [[Earth]], [[Venus]], [[Mars]], [[Europa (moon)|Europa]], [[io (moon)|Io]] and [[Titan (moon)|Titan]], visible impact craters may become [[erosion|eroded]], buried or transformed by [[tectonics]] over time. In early literature, before the significance of impact cratering was widely recognised, the terms [[cryptoexplosion]] or cryptovolcanic structure were often used to describe what are now recognised as impact-related features on Earth.<ref name="USRA-954">{{cite web | last1=French | first1=Bevan M. | authorlink=Traces of Catastrophe| year=1998 | url=http://www.lpi.usra.edu/publications/books/CB-954/CB-954.intro.html | title=Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures | location=Washington, DC | publisher=[[Smithsonian Institution]] | page=97 }}</ref> Molten terrestrial material ejected from a meteorite impact crater can cool and solidify into an object known as a '''[[tektite]]'''. These are often mistaken for meteorites.
| |
| | |
| ===Gallery of meteorites===
| |
| <center><Gallery style="margin:auto;">
| |
| Image:Willamette Meteorite AMNH.jpg|[[Willamette Meteorite]], discovered in the US state of Oregon
| |
| Image:Meteorite Lapham.jpg|Meteorite, which fell in [[Wisconsin]] in 1868.
| |
| File:Murnpeowie meteorite.jpg|Murnpeowie meteorite, a thumbprinted [[iron meteorite]].
| |
| Image:Meteorito Marília.jpg|Marília Meteorite, a chondrite H4, which fell in Marília, São Paulo state, Brazil, on October 5, 1971, at 17:00
| |
| File:Meteorite Tindouf NWA 869.jpg|Meteorite is from the NWA 869 strewn field, near [[Tindouf]], [[Algeria]]. Classified as a L5 COMMON CHONDRITE it shows [[breccia]]tion and [[carbon]] inclusions.<ref name="USRA-31890">{{cite web | url=http://www.lpi.usra.edu/meteor/metbull.php?code=31890 | title=Northwest Africa 869 | publisher=The Meteoritical Society | work=Meteoritical Bulletin Database | date= | accessdate= }}</ref>
| |
| </gallery></center>
| |
| | |
| ==See also==
| |
| | |
| ===Relating to meteoroids===
| |
| * [[Interplanetary dust]]
| |
| * [[Micrometeoroid]]
| |
| * [[Near-Earth object]]
| |
| | |
| ===Relating to meteors===
| |
| * [[North American Meteor Network]]
| |
| * [[American Meteor Society]]
| |
| * [[Green fireballs]]
| |
| * [[Hydrometeor]]
| |
| * [[International Meteor Organization]]
| |
| * [[Leonids]]
| |
| * [[List of meteor air bursts]]
| |
| * [[List of meteor showers]]
| |
| * [[Lyrids]]
| |
| * [[Orionids]]
| |
| * [[Perseids]]
| |
| * [[Tollmann's hypothetical bolide]]
| |
| | |
| ===Relating to meteorites===
| |
| * [[Baetylus|Baetylus—Sacred stones made from meteorites]]
| |
| * [[Impact crater]]
| |
| * [[Impact event]]
| |
| * [[Meteorite]]
| |
| * [[Micrometeorite]]
| |
| * [[Interplanetary dust cloud#Collecting interplanetary dust on earth|Stratospheric micrometeorites]]
| |
| * [[Tektite]]
| |
| | |
| ==References==
| |
| {{Reflist|3
| |
| | refs =
| |
| | |
| <ref name="IMO-meteoroid">{{cite web
| |
| |title=Glossary International Meteor Organization
| |
| |publisher=[[International Meteor Organization]] (IMO)
| |
| |url=http://www.imo.net/glossary#letterm
| |
| |accessdate=2011-09-16 }}</ref>
| |
| | |
| <ref name="Millman1961">{{cite journal
| |
| |last=Millman |first=Peter M.
| |
| |title=A report on meteor terminology
| |
| |journal=Journal of the Royal Astronomical Society of Canada
| |
| |volume=55 |pages=265–267 |year=1961
| |
| |bibcode=1961JRASC..55..265M }}</ref>
| |
| | |
| <ref name="Steel1995">{{cite journal
| |
| |last=Beech |first=Martin
| |
| |last2=Steel |first2=Duncan
| |
| |title=On the Definition of the Term Meteoroid
| |
| |journal=Quarterly Journal of the Royal Astronomical Society
| |
| |volume=36 |issue=3 |pages=281–284 |date=September 1995
| |
| |url=http://articles.adsabs.harvard.edu/full/1995QJRAS..36..281B
| |
| |bibcode=1995QJRAS..36..281B }})</ref>
| |
| | |
| <ref name="Rubin2010">{{cite journal
| |
| |last=Rubin |first=Alan E.
| |
| |last2=Grossman |first2=Jeffrey N.
| |
| |title=Meteorite and meteoroid: New comprehensive definitions
| |
| |journal=Meteoritics & Planetary Science
| |
| |volume=45 |issue=1 |pages=114–122 |date=January 2010
| |
| |bibcode=2010M&PS...45..114R
| |
| |url=http://onlinelibrary.wiley.com/doi/10.1111/j.1945-5100.2009.01009.x/abstract;jsessionid=49F5E412A475304A82B1E022F5B9270D.d04t03
| |
| |doi=10.1111/j.1945-5100.2009.01009.x }})</ref>
| |
| | |
| <ref name="smallest-jpl">{{cite web
| |
| |title=JPL Small-Body Database Search Engine: H > 29 (mag)
| |
| |publisher=JPL Solar System Dynamics
| |
| |url=http://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=all;obj_numbered=all;OBJ_field=0;ORB_field=0;c1_group=OBJ;c1_item=Ai;c1_op=%3E;c1_value=29;table_format=HTML;max_rows=100;format_option=comp;c_fields=AcBhBgBjBiBnBsCkCqAi;.cgifields=format_option;.cgifields=ast_orbit_class;.cgifields=table_format;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=com_orbit_class&query=1&c_sort=AiD
| |
| |accessdate=2013-01-28 }}</ref>
| |
| | |
| <ref name="NASA-166">{{cite web
| |
| |date=November 9, 2009
| |
| |title=Small Asteroid 2009 VA Whizzes By the Earth
| |
| |publisher=NASA's Near Earth Object Program Office
| |
| |first=Donald K. |last=Yeomans |first2=Paul |last2=Chodas |first3=Steve |last3=Chesley
| |
| |url=http://neo.jpl.nasa.gov/news/news166.html
| |
| |accessdate=2013-01-28 }}</ref>
| |
| | |
| <ref name="IMO-meteorites">{{cite web
| |
| |title=Fireballs and Meteorite Falls
| |
| |publisher=International Meteor Organization
| |
| |url=http://www.imo.net/fireball/meteorites
| |
| |accessdate=2013-03-05}}</ref>
| |
| | |
| <ref name="AMS-Fireball">{{cite web
| |
| |title=Fireball FAQS
| |
| |publisher=American Meteor Society
| |
| |url=http://www.amsmeteors.org/fireballs/faqf/#8
| |
| |accessdate=2013-03-05}}</ref>
| |
| | |
| <ref name=meteorsandtheirparentcomets>{{cite book|last=Jenniskens|first=Peter|title=Meteor Showers and their Parent Comets|year=2006|publisher=Cambridge University Press|location=New York|isbn=0521853494|page=372}}</ref>
| |
| }}
| |
| | |
| ==External links==
| |
| {{Commons|Meteor}}
| |
| {{wikisource index|Meteoroids}}
| |
| {{Wiktionary|meteoroid}}
| |
| {{Wiktionary|meteor}}
| |
| | |
| * [http://www.fireballhistory.com/ A History of Meteors and Other Atmospheric Phenomena]
| |
| * [http://www.amsmeteors.org/ American Meteor Society]
| |
| * [http://www.britastro.org/meteor British Astronomical Society meteor page]
| |
| * [http://www.imo.net International Meteor Organization]
| |
| * [http://www.meteorscan.com/meteor-live.html Live Meteor Screen]
| |
| * [http://solarsystem.nasa.gov/planets/profile.cfm?Object=Meteors Meteoroids Page] at [http://solarsystem.nasa.gov NASA's Solar System Exploration]
| |
| * [http://astroclub.tau.ac.il/ephem/Meteors/ Meteor shower predictions]
| |
| * [http://stardate.org/nightsky/meteors/ Meteor Showers and Viewing Tips]
| |
| * [http://www.popastro.com/meteor/index.php Society for Popular Astronomy - Meteor Section]
| |
| | |
| {{Small Solar System bodies}}
| |
| {{Solar System}}
| |
| {{Modern impact events}}
| |
| {{Planetary defense}}
| |
| | |
| [[Category:Meteoroids| ]]
| |
| | |
| {{Link FA|sr}}
| |