significant concentrations of sulfur dioxide in a planet's atmosphere can suggest that the planet is likely uninhabitable, allowing researchers to eliminate it from further consideration.

Instead, it's the opposite: Significant amounts of sulfur dioxide in a planet's atmosphere is a good sign that the world is uninhabitable and we can safely cross it off the list of candidates.

In less environmentally aware times, and when there were other, cheaper sources of sulfur ... while the remaining hydrogen sulfide and sulfur dioxide from the thermal step react on mixed beds ...

Sulfur dioxide, primarily released from burning fossil ... measures to reduce air pollution through cleaner energy sources, ...