The oldest light

To me 'microwave' is associated with drab meals, scalding hot on the outside, still frozen inside, rather than with anything as stunning as the image below. This is the first full-sky portrait 'taken' by Europe's Planck telescope. The map, which took 6 months to complete, records the light emitted by cosmic gas and dust. It also records the 'cosmic microwave background', or CMB as it's known, the oldest light in the universe (more on the BBC).

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Full-sky maps that record only visible starlight look very different, as do maps based on infrared or X-ray emissions. You can compare different views of the sky on Chromoscope. Here, for example, is another stunning portrait of the sky in near-infrared from WISE:

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