The moon takes a bite out of the sun's disk in this extreme ultraviolet view from NASA's Solar Dynamics Observatory.
The heavens have to align just right for a solar eclipse — and for NASA's Solar Dynamics Observatory, today was the day the heavens aligned. The only place where you could see today's partial eclipse was in outer space. But don't worry: Some of us earthlings will get a couple of chances later this year.
The Solar Dynamics Observatory watches the sun in multiple wavelengths of extreme ultraviolet light from a vantage point in geosynchronous orbit, about 22,000 miles (36,000 kilometers) above Earth's surface.
Sometimes other celestial bodies muscle in on SDO's view of the sun. Earth itself gets in the way twice a year, around the time of the spring and autumn equinoxes. Today, it was the moon's turn to take a bite out of the sun's bright disk.
Although this brief obstruction cut into the $850 million mission's observing time, the SDO team tried to make use of the opportunity, project scientist Dean Pesnell said in a blog posting. During its transit, the moon blocked the probe's view of an active region on the sun. That caused a dip in the energy recorded by the Extreme Ultraviolet Variability Experiment, or EVE, which "may allow scientists to calibrate the energy emitted by the active region," Pesnell said.
SpaceWeather.com's Tony Phillips mentions another opportunity provided by the eclipse: "The sharp edge of the lunar limb helps researchers measure the in-orbit characteristics of the telescope ... 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."
Observers in a wide swath of East Asia, the Pacific and western North America will be able to see a partial solar eclipse with their own eyes on May 20. Some lucky folks will see something even rarer: an annular eclipse, in which the moon covers up most of the sun but leaves a thin ring of the bright disk shining in the sky. The U.S. West Coast and Southwest will be prime territory for that "ring of fire" eclipse.
On Nov. 13, a total solar eclipse will be visible from a corner of Australia and a long strip of the Pacific Ocean. You'll be hearing a lot more about these eclipses as we get closer to the events. In the meantime, feast your eyes on this time-lapse view of the space eclipse:
Spectacular images of a partial solar eclipse caught on video by NASA's Solar Dynamics Observatory. NBC's Brian Williams reports.
More views of the sun:
Updated at 9:40 p.m. ET Feb. 23 to add the "Nightly News" video of the space eclipse.
Alan Boyle is science editor for msnbc.com. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding the Cosmic Log Google+ page to your circles. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.