... Well, probably not ... but it is the most active volcanic moon. Active volcanoes on Jupiter's moon Io were a surprise discovery of the Voyager missions of the late 1970s. Comet-like Clouds in the Cartwheel Galaxy . ... Apollo 12 Visits Surveyor 3 . ... Fliers Around the Blue Snowball Nebula . ... The Blue Snowball Planetary Nebula . ... The Blue Snowball is a planetary nebula - and in 5 billion years the Sun will throw off its outer layers and go through a planetary nebula phase. ...