Block Island meteorite

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Block Island meteorite
376060main PIA12161 full straightened and sharpened.jpg
Type Iron
Parent body Unknown
Composition Nickel, iron, Kamacite, taenite[1][2]
Weathering grade Large-scale, cavernous weathering[2]
Country Mars
Region Meridiani Planum
Coordinates 02°07′00.85″S 05°31′02.85″W / 2.1169028°S 5.5174583°W / -2.1169028; -5.5174583Coordinates: 02°07′00.85″S 05°31′02.85″W / 2.1169028°S 5.5174583°W / -2.1169028; -5.5174583[3]
Observed fall No
Fall date Possibly late Noachian
Found date 2009-07-17[4]
TKW >0.5 short tons (0.45 t)[5]
Strewn field Possibly[6]
Block Island.jpg
Block Island in close up.

Block Island meteorite was found on Mars by the Opportunity rover on 2009-07-17. It is about 67 centimetres (26 in) across.[1]

History[edit]

Block Island was the first of three iron meteorites encountered by the rover on Meridiani Planum within a few hundred meters, the others being Shelter Island (the second meteorite found), and Mackinac Island (the third one found).[2]

No strong evidence exists concerning when Block Island may have fallen on Mars, though atmospheric conditions would have favored its arrival in the late Noachian period. Block Island may be extensively weathered,[2][6] or conversely the features covering it may simply be the regmaglypts formed by its passage through the atmosphere. Contrary to some claims [5,6], Block Island is not too large for the modern martian atmosphere to produce, though the denser the atmosphere the more effectively it would produce Block Island mass meteorites.[7]

Mineralogy[edit]

Classification[edit]

See also[edit]

References[edit]

  1. ^ a b Nemiroff, Robert; Jerry Bonnell (13 August 2009). "2009 August 13". Astronomy Picture of the Day. NASA. Retrieved 5 January 2013. 
  2. ^ a b c d Ashley, J. W.; et al (July 2011). "Evidence for mechanical and chemical alteration of iron-nickel meteorites on Mars: Process insights for Meridiani Planum". Journal of Geophysical Research: Planets (1991–2012) 116 (E7). doi:10.1029/2010JE003672. Retrieved 5 January 2013. 
  3. ^ Google Mars
  4. ^ Atkinson, Nancy. "Opportunity Spies Unusual Rock — Large Meteorite?". Universe Today. Retrieved 5 January 2013. 
  5. ^ Staff (14 September 2010). "Mars' Odd 'Block Island' Meteorite - A Clue to an Ancient Atmosphere". Daily Galaxy. Retrieved 5 January 2013. 
  6. ^ a b Beech, Martin; Ian M. Coulson (2010). "The making of Martian meteorite Block Island". Monthly notices of the Royal Astronomical Society 404. doi:10.1111/j.1365-2966.2010.16350.x. Retrieved 5 January 2013. 
  7. ^ Chappelow, J. E.; Golombek M.P. (July 2011). "Event and conditions that produced the iron meteorite Block Island on Mars". Journal of Geophysical Research: Planets (1991–2012) 115 (E12). doi:10.1029/2010JE003666.