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: [email protected] 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 shoo ng 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 Antarc ca 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 robo c moving vehicle.
METEOROIDS • 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.
BOLIDES Bolide is either an extraterrestrial body that collides with the Earth, or an excep onally bright, fireball-like meteor regardless of whether it finally impacts the surface. WHERE METEORITES ORIGINATE FROM? Most meteorites are fragments of small planets sha ered 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 con nuously circle the Sun between the orbits of MARS and JUPITER 230-780 million km away!
ORBITS OF KNOWN METEORITES PRIBRAM
The first meteorite to have its fall to Earth recorded by a camera network, enabling its inbound trajectory and LOSTCITY orbit to be determined and the meteorite to be recovered. Cameras operated by the Ondrejov Observatory in the Czech LOST CITY Republic recorded a brilliant fireball on Apr. 7, 1959. 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 HOW BIG ARE THEY? Meteoroids have a pre y 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 en rely 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 composi on. 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 cen meters long, has been illuminated from behind to dis nguish 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.
Apophis
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 es mated there was a 2.7% chance of impact in 2029, and it Close approach of Apophis on will create a crater of a diameter April 13, 2029 (as known in 4.3 km. February 2005
New informa on has shown we're safe a er all!
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.
The white bar indicates uncertainty in the range of positions (as known in February 2005) Apophis Hypothe cal Impact Scenario
θ APOPHIS EARTH IMPACT: HYPOTHETICAL SCENARIO
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.
ENERGY CALCULATION AND ATMOSPHERIC ENTRY • 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.
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.
TSUNAMI WAVE
The impact-generated tsunami wave arrives approximately 21.3 minutes after impact.
Tsunami wave amplitude is less than 4.7 meters ( = 15.4 feet).
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 me 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
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