Our planet has more than 1,500 volcanoes – but if you think that’s a lot then take a look at Venus. A new map, created from radar imagery collected during Nasa’s Magellan mission in the 1990s, catalogues more than 85,000 volcanoes on Venus, 99% of which are less than 5km in diameter. “Our new database will enable scientists to think about where else to search for evidence of recent geological activity [on Venus],” says Paul Byrne from Washington University in St Louis. Although there were volcanoes virtually everywhere on the planet, Byrne and his colleagues report in the journal JGR Planets that volcanoes in the 20km- to 100km-diameter range are relatively scarce; a fact that may help us learn more about magma availability and eruption rates on Venus. The researchers hope the data, which is publicly available, will help them better understand the inner workings of the planet. The volcano map comes hot on the heels of the first proof that Venus has active volcanoes, reported in the journal Science. Playing “spot the difference” with radar images from the Magellan mission, researchers identified a volcanic vent on the massive Maat Mons volcano, which had enlarged and changed shape over an eight-month period, with new lava flows appearing in the latter images.