Search engine Google has updated its online map of the world to allow users to "dive into the sea and glide over the ocean floor". Google Ocean uses photographs and video of fish and other marine life from partners including the National Geographic Society. The latest version of Google Earth also provides a way to view changes to glaciers and other geography over time. A new "timeline" feature allows a user to view a succession of satellite images of the same location over many years, tracking changes to the environment. It has been praised by former US Vice President and campaigner Al Gore for its ability to raise awareness about environmental issues such as global warming. In developing Google Ocean, the company used sonar data from the US Navy, the National Oceanic and Atmospheric Association and others to create a visual representation of the topographic landscape hidden beneath the sea. Google also unveiled a three-dimensional map of Mars based on satellite images and panoramic photos taken from the Mars Rovers.