While many in the U.S. experienced a total solar eclipse on Aug. 21, 2017, NASA’s Solar Dynamics Observatory, or SDO — observing the Sun from Earth orbit — saw a partial eclipse.
SDO sees several lunar transits each year from its orbit 3,000 miles above Earth. However, an eclipse on the ground doesn’t guarantee that SDO will see anything out of the ordinary. On Aug. 21, SDO also saw the Moon briefly pass in front of the Sun at the same time that the Moon’s shadow passed over the eastern United States. SDO only saw 14 percent of the Sun blocked by the Moon, while most U.S. residents saw 60 percent blockage or more.