ROCKS  FROM  SPACE  CALLED  METEORITES    Ioannis Haranas

Dept. of Physics and Computer Science , Wilfrid Laurier University , 75 University Ave. W. Waterloo, ON, N2L 3C5, CANADA

e-mail: iharanas@wlu.ca

The  word  meteor  is  derived  from  the  Greek  word    Μετέωρος  (meteoros)  =  Suspended  in  the  air  Rocks  from  space  can  be  classified  in  4  different    categories:  

     1.  Meteorites        2.  Meteors  (also  called  shooXng  stars)  2  3.  Micrometeorides    4.  Bolides  

 

Meteorite  (Earth  Fall)  Meteorite  is  a  solid  debris  piece,  which  survives  impact  with  the  Earth's  surface  a]er  moving  through  the  Earth’s  atmosphere.    

One  of  the  ~400  meteorites  recovered  from  AntarcXca  during  the  2012-­‐2013  season.    (Image  from  Planetary  Science  Research  Division  at  the  University  of  Hawai’i-­‐  Manoa)    

Meteorite:  MARS  FALL  

Iron  meteorites  on  the  surface  of          Mars.    This  is  Mars  Rover  taken  picture.  Discovery  Rover  is  roboXc  moving  vehicle.  

 

    • A  meteoroid  is  a  small  rocky  or  metallic  body  traveling  through  space.    

• It  is  called  a  meteoroid  just  before  it  falls  on  the  surface  of  the  Earth.    

• Meteoroids  are  significantly  smaller  than  asteroids,  and  range  in  size  from  small  grains  to  1  meter-­‐wide  objects.  

• Around  15,000  tones  of  meteoroids,  micrometeoroids  and  different  forms  of  space  dust  enter  Earth's  atmosphere  each  year.  

 

METEOROIDS  

BOLIDES  Bolide  is  either  an  extraterrestrial  body  that  collides  with  the  Earth,  or  an  excepXonally  bright,  fireball-­‐like  meteor  regardless  of  whether  it  finally  impacts  the  surface.    

WHERE  METEORITES  ORIGINATE  FROM?  Most  meteorites  are  fragments    of  small  planets  shakered  by    collisions  early  in  the  history  of  the  Solar  System.    They  are  now  called  asteroids    or  comets,  that  originate    in  outer  space.    These  remnants  form  the  Asteroid    Belt,  where  many  thousands  of    small  objects  conXnuously  circle    the  Sun  between  the  orbits  of    MARS  and  JUPITER  230-­‐780  million    km  away!    

ORBITS  OF  KNOWN  METEORITES  

CITYLOSTCITYLOST

LOST  CITY  

PRIBRAM  

The second meteorite fall to be recorded by a camera network, thus enabling its trajectory and orbit to be determined and a quick recovery of the fragments, which weighed a total of 17 kg. The Lost City meteorite was found upon analysis to be an H5 chondrite. Jan. 3, 1970

The first meteorite to have its fall to Earth recorded by a camera network, enabling its inbound trajectory and orbit to be determined and the meteorite to be recovered. Cameras operated by the Ondrejov Observatory in the Czech Republic recorded a brilliant fireball on Apr. 7, 1959.

HOW  BIG  ARE  THEY?  Meteoroids  have  a  preky  big  size  range.        They  include  any  space  debris  bigger  than  a  molecule  and  smaller  than  about    100  meters  objects.  

 Anything  bigger  than  100  m  this  is  considered  an  Asteroid.  

HOW  MANY  DIFFERENT  KINDS  ARE  THERE?  WHAT  ARE  THEY  MADE  OFF?  

IRON  METEORITES  (Fe, Ni & Co (>95%), Ni (5%-25 )  :  Most  iron  

meteorites  likely  originate  in  the  cores  of  large  asteroids,  and  are  

composed  almost    enXrely  of  nickel-­‐iron  alloy,  and  represent  only  

5%  of  the  falls.      

Rancho  Gomelia,  Mexico,  Octahedrite.  This  iron  meteorite  has  been  cut,  polished  and  etched  with  acid  on  one  face  to  reveal  an  interlocking  crystal  structure  of  nickel-­‐iron  alloys  of  varying  composiXon.  Photo  by  D.  Ball,  ASU    

         STONY  METEORITES  (Mg2SiO4  ):    •  The  most  common  type  of  meteorite,  are  generally  composed  of  approximately  75  to  90  %  silicon-­‐based  minerals.    

•  Stony  meteorites  account  for  94  %  of  observed  meteorite  falls.    

Warden;  an  ordinary  (H5)  chondrite  from  Western  Australia.      Photo  ©  D.  Ball,  ASU    

 STONY  –  IRON  METEORITES        (50%  nickel-­‐iron  and  50%  silicate  material  ):    •  Stony-­‐iron  meteorites  contain  approximately  even  amounts  of  silicates  and  nickel-­‐iron  alloy 1-2% of meteorites.

Albin,  WY,  pallasite.    This  slice,  which  is  about  18  cenXmeters  long,  has  been  illuminated  from  behind  to  disXnguish  its  olivine  content  from  the  surrounding  metal.    Photo  by  D.  Ball,  ASU.    

HOW FAST DO THEY MOVE? WHY THEY SOMETIMES FALL ON THE EARTH? ARE THEY A PART OF OUR SOLAR SYSTEM?   They enter Earth’s atmosphere at velocity from 11 to

70 km per second (km/s).

  Meteors can fall on Earth for any sort of reason. The

main reason is that they are loose bits of rock which

have escaped gravitational pull of a planet and the

earth has more mass and therefore pulls them into

our planet.

  They are part of the original material that formed the

Solar System.

NASA  is  tracking  over  800  objects    of  more  than  1km  across,  and  anything  with  a  diameter    of  over  3km  is  considered  a  global  catastrophic  risk.      The  biggest  recent  scare  was    from  APOPHIS  which  is  around  325  meters  across.  When  it  was    discovered  in  2004,  it  was  esXmated  there  was  a  2.7%    chance  of  impact  in  2029,  and  it  will  create  a  crater  of  a  diameter  4.3  km.      New  informaXon  has  shown  we're  safe  a]er  all!    

Close  approach  of  Apophis  on  April  13,  2029  (as  known  in  February  2005    

Apophis

The white bar indicates uncertainty in the range of positions (as known in February 2005)

Is a near-Earth asteroid that caused a brief period of concern in

December 2004 because initial observations indicated a probability

of up to 2.7% that it would hit Earth on April 13, 2029.

Apophis  HypotheCcal  Impact  Scenario  

θ

COMPUTER INPUT MODEL SIMULATION PARAMETERS

• Distance from Impact: 120.00 km ( = 74.50 miles ) Toronto –Waterloo

distance

• Projectile diameter: 325.00 meters ( = 1070.00 feet )

• Projectile Density: 3200 kg/m3

• Impact Velocity: 30.70 km per second ( = 19.10 miles per second )

• Impact Angle: 10 degrees

• Target Density: 1000 kg/m3

• Target Type: Liquid water of depth 5.0 km ( = 3.1 miles ), over

crystalline rock.

APOPHIS  EARTH  IMPACT:  HYPOTHETICAL  SCENARIO

•  Energy before atmospheric entry: 2.72 x 1019 Joules = 6.49 x 103 MegaTons TNT

• The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 9.5 x 104years

• The projectile begins to breakup at an altitude of 61.50 km

• The projectile bursts into a cloud of fragments at an altitude of 16.5 meters

• The residual velocity of the projectile fragments after the burst is 5.99 km/s

• The energy of the airburst is 2.61 x 1019 Joules = 6.24 x 103 MegaTons.

• No crater is formed, although large fragments may strike the surface.

ENERGY CALCULATION AND ATMOSPHERIC ENTRY

MAJOR GLOBAL CHANGES

• The Earth is not strongly disturbed by the impact and loses

negligible mass.

• The impact does not make a noticeable change in the tilt of Earth's

axis (< 5/100 = 0.05 of a degree).

• The impact does not shift the Earth's orbit noticeably.

AIR BLAST

• The air blast will arrive approximately 6.06 minutes

after impact.

• Peak Overpressure: 17100 Pa = 0.171 bars = 2.43 psi

• Max wind velocity: 37.6 m/s = 84.1 mph

• Sound Intensity: 85 dB (Loud as heavy traffic)

• Damage Description: Glass windows will shatter.

The impact-generated tsunami wave arrives approximately 21.3 minutes after impact. Tsunami wave amplitude is less than 4.7 meters ( = 15.4 feet).

TSUNAMI WAVE

HOW  IS  THE  EARTH  PROTECTED?  YOU  CAN  CALL    EARTHS  NATURAL    PROTECTION    MECHANISM!  HOW  IS  THIS  POSSIBLE?    

This  is  Earth’s  strange  companion:    Near-­‐Earth  asteroid  3753  Cruithne.    

Its  orbit  was  first  Xme  predicted  in  1997      by  two  Canadian  York  University    astronomers  ,  Dr.  P.Weigert  and    Dr.  K.  Innanen,  and  Dr.  S.  Mikkola    from  Univ.  of  Turku,  Finland  .      

This  curious  5    km  in  diameter    companion  it  takes  770  years  for    the  to  complete  a  horseshoe-­‐shaped.    Every  385  years,  it  comes  to  its  closest    point  around  the  Earth.    

GRUINTHE  THROUGH  TELESCOPE  

Gruithne: historical people known to have lived in the British Isles during the Iron Age

VARIOUS  METEORITE  SAMPLES    THA  HAVE    FALLEN  ON  THE  EARTH  

This  is  a  close  up  picture  of  our  Campo  del  Cielo  Meteorite  from  surface  cut  (Patrick  Herman,  Toronto  2014)   Campo del Cielo 1,000

kilometers northwest of Buenos Aires, Argentina.

El  Chaco:  The  37  ton  Main  Mass  of  the  Campo  del  Cielo  Iron  Meteorite  1  ton=  1000  kilogram  

THANK  YOU!!!