Space volcanoes spouting their stuff

In this image of Io we can see at least three active volcanoes ejecting material into space.

The volcanic gass, ash and dust can get much higher into Io's atmosphere because the moon has less gravity. Some of it goes high enough that it escapes directly into space.

The lumpy looking things on the edge of the zone in shadow are other massive volcanoes no less active but just not erupting at this time.

By NASA - http://www.nasa.gov/mission_pages/newhorizons/news/jupiter_images.html, Public Domain, Link