- The shergottite, nakhalite and chassignite meteorites, thought to have come to the Earth from Mars. The shergottites are thought to have suffered most alteration during the impact process which led to their ejection into space. They have been used to provide information on the geological history of Mars and on its atmosphere and water resources. They seem to be igneous rocks 200 million to 1.3 billion years old, and the isotope composition of nitrogen bubbles in them seems to resemble that in the atmosphere of Mars.
- acronym forUnidentified Flying Object