Researchers have known for decades that Venus' surface is mottled with volcanoes, but determining whether those volcanoes are dormant or active from a distance is tricky. Using data collected from the European Space Agency's now-dead orbiter, Venus Express, scientists have found several hints of residual volcanic activity in the planet's atmosphere, including hotspots of searing heat and blips of sulfur dioxide, the gassy calling card of active volcanoes here on Earth.