The scientists say the detector refers to the Viking 1 and Viking 2 that NASA sent to Mars more than 40 years ago. Their main task is to analyze the samples of Martian soil and search for the key components of life, organic molecules. However, they did not find evidence of alien life, and eventually had to "return empty handed."
However, this year, the curiosity rover has found evidence of life support on Mars, and confirms that there is life supporting organic matter on Mars. This had to allow scientists to begin to doubt the authenticity of the two detector data in the Viking program.
Scientists found that there are many perchlorate in Martian soil, which have high chemical activity. Scientists believe that they are likely to be heated, exploded in the laboratory of the Viking series and destroy all traces of organic matter, causing a lot of change in the soil.
The report points out that this view of scientists is not based on nothing but the support of data collected during the "Viking" mission. Scientists found chlorobenzene in soil samples from the Viking probe, which only appeared after combustion of carbon molecules and perchlorate.
However, there are also some objections from scientists. They believe that the chlorobenzene discovered by the Viking probe may come from the earth material carried by the detector itself.