Who needs Google Earth? NASA and Japan just improved the most complete -- and free -- digital topographic map of Earth.
The Japanese Advanced Thermal Emission and Reflection Radiometer, or ASTER, is an instrument on board NASA's Terra spacecraft. The map it produces is called a global digital elevation model, and gets its 3D effect by combining two slightly offset two-dimensional images.
The update to the ASTER data adds 260,000 images to the already-expansive map and improves basically every measurement -- spatial recognition, horizontal and vertical accuracy, recognition of bodies of water. The map covers 99 per cent of Earth's landmass, and its measurement points are just 30m apart.
The data's been validated by NASA, METI, Japan's Earth Remote Sensing Data Analysis Center (ERSDAC), and the US Geological Survey, and the US National Geospatial-Intelligence Agency, but users are still warned that there will be a few "anomalies and artifacts" that limit its use for certain projects. Though I'm fairly certain they don't mean Google-Maps-like hiccups that'll end in a wrong turn into a volcano. [NASA]