# Heat Shield Rock - Page: https://taslar.bumba.tr/en/stones/heat-shield-rock/ - Turkish: Isı Kalkanı Kayası - Also known as: Meridiani Planum meteorite - Kind: Meteorite - Classification: Meteorites and impact stones › Iron meteorites - Hardness (Mohs): 4–5.5 - Specific gravity: 7–8 g/cm³ - Lustre: Metallic - Transparency: Opaque - Colours: dark grey, metallic dark brown - Composition: Iron–nickel meteorite: 93% iron, 7% nickel, with traces of germanium (about 300 ppm) and gallium (under 100 ppm). The iron is mainly metallic; the main mineral is kamacite with 5–7% nickel. Its composition is essentially identical to a typical IAB iron meteorite found on Earth. - Texture: Massive metal; its surface shows regmaglypts, thumbprint-like pits formed by melting and ablation during atmospheric passage. Its longest dimension is nearly 31 cm. - Value ladder: 6/9 step, Fine ornamental and collector stone The first meteorite found on another planet: a basketball-sized iron the rover Opportunity came across on Mars in 2005, next to its own heat shield. Heat Shield Rock is a basketball-sized iron–nickel meteorite found on the Meridiani Planum plain of Mars by NASA's Opportunity rover in January 2005. It got its name because it was found by chance near the rover's own discarded heat shield; the Meteoritical Society formally named it the “Meridiani Planum meteorite” in October 2005. It was the first meteorite found on another planet and the third found on another body in the Solar System. ## How does it form? Heat Shield Rock is an iron–nickel meteorite very like the IAB iron meteorites that fall on Earth. Meteorites like this come from the metal parts of asteroids formed early in the Solar System. This piece of metal drifting through space one day entered Mars's atmosphere and fell to the surface. Passing through the atmosphere, its surface melted and wore away, forming thumbprint-like pits. To survive largely undeformed, it must have hit at less than about 1.5 kilometres per second. When it fell is unknown; Meridiani Planum is thought to have once been covered by up to 1 kilometre of material that has since eroded away. ## What is it used for? - **Mars's past:** Its impact speed and lack of rust give clues to the history of the Martian atmosphere and surface conditions. - **Planetary science:** Meteorites found on other planets help study how meteorites are spread through the Solar System and how planetary surfaces weather. - **History of space exploration:** As the first meteorite found on another planet, it has a special place in the history of space exploration. ## How was it found? After leaving Endurance crater, Opportunity was sent to examine the heat shield it had dropped during landing, and came across the meteorite by chance. Its Mini-TES spectrometer showed the rock was unusual; the APXS instrument measured its composition, and Mössbauer spectra confirmed that the iron was mainly metallic. This settled that the rock was an iron–nickel meteorite. ## How to recognise it - Its surface shows regmaglypts, the thumbprint-like pits typical of meteorites that have passed through an atmosphere. - It first stood out because its infrared spectrum looked surprisingly like a reflection of the sky. - It is 93% iron and 7% nickel, very like IAB iron meteorites on Earth. ## What determines its value? Heat Shield Rock lies on Mars, so it is not a collector's item; its value is purely scientific. As the first meteorite found on another planet it has historic importance, and it tells us about the past of Mars's atmosphere and surface. This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment. ## Myths and misconceptions - Myth: Heat Shield Rock is a “Martian meteorite”. Fact: “Martian meteorite” means rocks that broke off Mars and fell to Earth; ALH 84001 is a famous example. Heat Shield Rock is the opposite: a meteorite from space that fell on Mars and was found on Mars. ## Curious questions **What can a meteorite found on Mars tell us?** To survive largely undeformed, it must have hit Mars at less than about 1.5 kilometres per second, which gives a clue to how dense the Martian atmosphere was when it fell. Its lack of rust also says something about surface conditions, though when it fell is not known. ## Did you know? - Opportunity's Rock Abrasion Tool was never used on it: tests on iron meteorites on Earth had shown the tool would be worn and damaged by iron–nickel alloy. - The only meteorites found earlier on another body in the Solar System were the millimetre-sized Bench Crater and Hadley Rille meteorites on the Moon. - After Heat Shield Rock, Opportunity found five more iron–nickel meteorites, Spirit two and Curiosity one. ## Sources - [Heat Shield Rock](https://en.wikipedia.org/wiki/Heat_Shield_Rock), Wikipedia - [Isı Kalkanı Kayası](https://tr.wikipedia.org/wiki/Is%C4%B1_Kalkan%C4%B1_Kayas%C4%B1), Vikipedi - [Kamacite Mineral Data](http://webmineral.com/data/Kamacite.shtml), Webmineral.com - [Taenite Mineral Data](http://webmineral.com/data/Taenite.shtml), Webmineral.com - [Density and specific gravity (R. L. Korotev)](https://sites.wustl.edu/meteoritesite/items/density-specific-gravity), Washington University in St. Louis, Some Meteorite Information Source: https://taslar.bumba.tr/en/stones/heat-shield-rock/ · Licence: CC BY-SA 4.0