3D coronal hole - October 21, 2007

A 3D coronal hole seen just to the right of the Sun's center in extreme UV light from the STEREO's Behind spacecraft in the 195 Angstrom wavelength. Coronal holes, which appear darker when observed in UV light) are magnetically open areas from which the high-speed solar wind streams into space. This is not a true 3D image (taken from two perspectives at the same time). This image was created by combining two images taken 12 hours apart during which the Sun's rotation provides sufficient perspective to create a nice 3D effect. The coronal hole is changing slowly enough that it is possible to use this technique.

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TIFF: 3D left right