Heat Shield Rock is a basketball-sized iron-nickel meteorite found on the Meridiani Planum plain of Mars by the Mars rover Opportunity in January 2005.

Informally referred to as "Heat Shield Rock" by the Opportunity research team, the meteorite was formally named Meridiani Planum meteorite by the Meteoritical Society in October 2005 (meteorites are always named after the place where they were found).

Discovery

Opportunity encountered the meteorite entirely by chance, in the vicinity of its own discarded heat shield (hence the name). Opportunity had been sent to examine the heat shield after exiting the crater Endurance. This was the first meteorite found on another planet and the third found on another Solar System bodytwo others, the millimeter-sized Bench Crater and Hadley Rille meteorites, were found on the Moon.

Analysis

The rock was initially identified as unusual in that it showed, from the analysis with the Mini-TES spectrometer, an infrared spectrum that appeared unusually similar to a reflection of the sky. In-situ measurements of its composition were then made using the APXS, showing the composition to be 93% Iron, 7% nickel, with trace amounts of germanium (~300 ppm) and gallium (<100 ppm). Mössbauer spectra show the iron to be primarily in metallic form, confirming its identity as an iron-nickel meteorite, composed of kamacite with 5–7% nickel. This is essentially identical to the composition of a typical IAB iron meteorite found on Earth. The surface of the rock shows the regmaglypts, or pits formed by the ablation of a meteorite during passage through the atmosphere, characteristic of meteorites. The largest dimension of the rock is nearing 31&nbsp;cm. "Mackinac Island", "Oileán Ruaidh" and "Shelter island"). Two nickel-iron meteorites were identified by the Spirit rover (informally named "Allan Hills" and "Zhong Shan"). One nickel-iron meteorite has been identified by the Curiosity rover, tagged "Lebanon." In addition, several candidate stony meteorites have also been identified on Mars.

Terminology

The term "Martian meteorite" usually refers to something entirely different: meteorites on Earth which are believed to have originated from Mars, a famous example being ALH84001.

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See also

References

Further reading

  • D. S. Rodionov, et al., "An Iron-Nickel Meteorite on Meridiani Planum: Observations by MER Opportunity’s Mössbauer Spectrometer," European Geosciences Union; Geophysical Research Abstracts, Vol. 7, 10242; 1607-7962/gra/EGU05-A-10242 (2005).
  • Christian Schröder, et al., "Meteorites on Mars observed with the Mars Exploration Rovers," Journal of Geophysical Research: Planets, v. 113(E6), E06S22, (2008).
  • A. S. Yen, et al., "Nickel on Mars: Constraints on Meteoritic Material at the Surface," Journal of Geophysical Research: Planets, v. 111, E12S11, (2006).
  • G. A. Landis, "Meteoric Steel as a Construction Resource on Mars,", Acta Astronautica, Vol. 64, No. 2–3 (Jan–Feb. 2009). Presented at the Ninth Space Resources Roundtable, Colorado School of Mines, October 2007 presentation, 5.9 mb (powerpoint)
  • Nasa's Mars Exploration Program
  • NASA announcement
  • NAA Opportunity Archive: sol-by-sol account of the program and the discovery of Heat Shield Rock
  • JPL meteorite image
  • JPL Photojournal entry on meteorite
  • Sky & Telescope article
  • Space.com article
  • Article in Meteoritical Bulletin
  • Official Mars Rovers site
  • Meteorites Found on Mars Planetary Science Research Discoveries article.