Planet Earth is the only example we have of what a habitable planet 'looks' like. Using observations from NASA's Terra, QuikSCAT, and Aura missions, researchers have now developed a 3-D Spectral Earth Model that simulates the appearance of the Earth under a variety of conditions. Researchers with the NASA Astrobiology Institute's Virtual Planetary Laboratory (VPL) and NASA's EPOXI mission team have shown that the model's predictions are a near-perfect match to actual EPOXI and Aqua observations. It can also accurately simulate the whole-disk image of Earth at different wavelengths. The data was published in the July issue of the journal Astrobiology, and it will help astrobiologists test methods for characterizing Earth-sized planets around distant stars. Ultimately, accurate simulations of the Earth could help scientists identify habitable, extrasolar worlds.