Assertion: spacecraft's array | /r/CapableOf | measure magnesium
Facets:
Source sentences:
text: The robotic arm scooped up some soil and put it in one of four wet chemistry lab cells, where water was added, and, while stirring, an array of electrochemical sensors measured a dozen dissolved ions such as sodium, magnesium, calcium, and sulfate that leached out from the soil into the water.