Villarrica Volcano Against the Sky

Explanation: When Vulcan , the Roman god of fire, swings his blacksmith's hammer, the sky is lit on fire . A recent eruption of Chile 's Villarrica volcano shows the delicate interplay between this fire -- actually glowing steam and ash from melted rock -- and the light from distant stars in our Milky Way galaxy and the Magellanic Clouds galaxies. In the featured timelapse video , the Earth rotates under the stars as Villarrica erupts . With about 1350 volcanoes , our planet Earth rivals Jupiter's moon Io as the most geologically active place in the Solar System . While both have magnificent beauty, the reasons for the existence of volcanoes on both worlds are different. Earth's volcanoes typically occur between slowly shifting outer shell plates , while Io 's volcanoes are caused by gravitational flexing resulting from Jupiter 's tidal gravitational pull .