IYL 2015 Images

  • earth_namerica

    Earth – North America

    This image of Earth, known as the "Blue Marble" from NASA, is so familiar that most of us consider it to be our planetary self-portrait. But did you know that the Earth does not actually emit any of the light in this famous image? Rather, all of the light seen here is reflected from the Sun. Earth does give off some light, but not in the form we can see with our eyes. Our planet emits some infrared radiation, or heat, which is energy absorbed from the Sun and re-radiated at longer wavelengths. A small amount Earth's infrared radiation–a fraction of a percent–also comes from the radioactive decay of elements in Earth's mantle and crust as well as residual heat left over from when the planet formed. Scientists can detect that infrared light using special instruments and detectors.
    Image Credit: Reto Stöckli for the NASA GSFC Earth Observatory
    view and download image here. http://lightexhibit.org/photoindex.html

  • sunset_orbit

    Sunrise From Space

    Despite being 93 million miles from the Earth, the Sun delivers approximately 5 trillion giga-joules of energy to the Earth's surface every year. This is a tremendous amount of energy. In fact, if we could harness just one day's worth of the Sun's energy that reaches us, we could power the entire planet's energy needs for seven decades. Of course, it's not technologically feasible to try to capture all of the Sun's output, but the Sun holds enormous potential for providing energy to the Earth's inhabitants. As solar panels gain in efficiency and other advances are made, look to the Sun and its light to play an important role in powering the planet and its needs.
    Image Credit: NASA/JSC
    view and download image here. http://lightexhibit.org/photoindex.html