Achondrite

<p>An achondrite is a stony <a href="/facts/Meteorite/NsmHlBlX">meteorite</a> that does not contain <a href="/facts/Chondrule/eEcYvcoq">chondrules</a>. It consists of material similar to terrestrial <a href="/facts/Basalt/uhbwGPTb">basalts</a> or <a href="/facts/Plutonic/Wl6xaY1a">plutonic</a> rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes.
</p><p>Achondrites account for about 8% of meteorites overall, and the majority (about 
  
    
      
        2
        
          /
        
        3
      
    
    {\displaystyle 2/3}
  
) of them belong to the <a href="/facts/HED_meteorite/5W2K84zC">HED clan</a>, possibly originating from the crust of asteroid <a href="/facts/4_Vesta/xnQ8acw1">Vesta</a>. Other types include <a href="/facts/Martian_meteorite/kp9vW6RM">Martian</a>, <a href="/facts/Lunar_meteorite/gpq02Hsf">Lunar</a>, and several types thought to originate from as-yet unidentified <a href="/facts/Asteroid/g7Ulr1VB">asteroids</a>. These groups have been determined on the basis of e.g. the <a href="/facts/Iron/QK1JYy8E">Fe</a>/<a href="/facts/Manganese/j9ELd1TL">Mn</a> chemical ratio and the 17O/18O <a href="/facts/Oxygen/acyn6o8r">oxygen</a> <a href="/facts/Isotope/KD9B1y6o">isotope</a> ratios, thought to be characteristic "fingerprints" for each parent body.
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Achondrite open-in-new

Achondrite