[Comment on “Martian soil simulant available for scientific, educational study”] Caution advised on suitability of a Mars soil simulant

Abstract
JSC Mars‐1 is a recently announced simulant for the Mars soil “available for scientific, educational study” [Allen et al., 1998]. It is a somewhat altered volcanic ash from a Mauna Kea, Hawaii, cinder cone that yields a reflectance spectrum remarkably similar to the Olympus‐Amazonis bright region on Mars [see Allen et al., 1998,Figure 1].The comparability in terms of other chemical and physical properties of the simulant to what is considered to be known of the properties of Mars soil is outlined, and an acceptable similarity is implied. We wish, however, to point out several shortcomings in this Martian analog, to caution researchers and teachers that “looks can be deceiving,” and that they should not conclude that because of the spectral similarity, Mars soil must necessarily be “altered volcanic ash.” It may well prove to be ash in some form but this sample is not the answer.