Tue, 21 Feb 2012 11:21 CST
Today, the new Moon passed in front of the sun, off-center, producing a partial solar eclipse. The only place to see it was from space. NASA's Solar Dynamics Observatory (SDO) sends this picture from geosynchronous orbit approximately 36,000 km above Earth's surface:
Using a bank of 16 megapixel cameras, SDO observed the event at multiple extreme ultraviolet wavelengths. Scan the edge of the Moon in this 171 Å image:
The little bumps and irregularities you see are lunar mountains backlit by solar plasma.
Beyond the novelty of observing an eclipse from space, these images have practical value to the SDO science team. The sharp edge of the lunar limb helps researchers measure the in-orbit characteristics of the telescope--e.g., how light diffracts around the telescope's optics and filter support grids. Once these are calibrated, it is possible to correct SDO data for instrumental effects and sharpen the images even more than before.
The next solar eclipse visible from Earth's surface occurs on May 20, 2012: video.