What implication does the detection of chlorine, sulfur, and potassium have on the prior classification of Mercury's bulk composition?
It shifts Mercury from being purely refractory to one that incorporated materials from cooler solar system regions.
Before the detection of elements like potassium, sulfur, and chlorine, standard models often treated Mercury as a purely refractory body, meaning it formed only from materials that condense at very high temperatures. The inclusion of these moderately volatile elements means Mercury must have incorporated material that formed in cooler zones of the early solar nebula, or that material must have been shielded from the solar heating during the planet's initial development. This finding necessitates Mercury being reclassified as having a mixed composition that clearly incorporated materials formed under less extreme thermal conditions.
