Sidoarjo mud flow. False colour satellite images of Sidoarjo, East Java, Indonesia. The image at left was taken on 24th August 2004, vegetation is red, bare ground is blue and green, water is black. The image at right was taken on 11th November 2008 over 2 years after a mud volcano started erupting and caused a massive mud flow. Mud from the volcano is grey. The mud breached early containment walls, displacing 30,000 villagers. In the later image the mud is mostly contained by levees. Image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite.