![Awter Awter](/uploads/1/2/5/6/125613339/976100001.jpg)
![Calcium perchlorate formula Calcium perchlorate formula](/uploads/1/2/5/6/125613339/664145400.png)
Results from the Viking biology experiments indicate the presence of reactive oxidants in martian soils that have previously been attributed to peroxide and superoxide. Instruments on the Mars Phoenix Lander and the Mars Science Laboratory detected perchlorate in martian soil, which is nonreactive under the conditions of the Viking biology experiments.
NASA.gov brings you the latest images, videos and news from America's space agency. Get the latest updates on NASA missions, watch NASA TV live, and learn about our quest to reveal the unknown and benefit all humankind.
We show that calcium perchlorate exposed to gamma rays decomposes in a CO 2 atmosphere to form hypochlorite (ClO −), trapped oxygen (O 2), and chlorine dioxide (ClO 2). Our results show that the release of trapped O 2 (g) from radiation-damaged perchlorate salts and the reaction of ClO − with amino acids that were added to the martian soils can explain the results of the Viking biology experiments. We conclude that neither hydrogen peroxide nor superoxide is required to explain the results of the Viking biology experiments. Key Words: Mars—Radiolysis—Organic degradation— in situ measurement—Planetary habitability and biosignatures. Astrobiology 13, 515–520.