Other meteorites that have potential biological markings have generated less interest because they do not contain rock from a "wet" Mars; ALH84001 is the only meteorite originating when Mars may have had liquid surface water.
[3]
In October 2011, it was reported that isotopic analysis indicated that the
carbonates in ALH84001 were precipitated at a temperature of 18 °C (64 °F) with water and
carbon dioxide from the
Martian atmosphere. The carbonate carbon and oxygen isotope ratios imply deposition of the carbonates from a gradually evaporating subsurface water body, probably a shallow aquifer meters or tens of meters below the surface.
[9]
In April 2020, researchers reported discovering nitrogen-bearing organics in Allan Hills 84001.
[15]
A later study in January 2022 concluded that ALH84001 did not contain Martian life; the discovered organic molecules were found to be associated with abiotic processes (i.e., "serpentinization and carbonation reactions that occurred during the aqueous alteration of basalt rock by hydrothermal fluids") produced on the very early Mars 4 billion years ago instead.
[16][17]