NASA’s Solar Dynamics Observatory Spots First Lunar Transit of 2021
Credit: NASA’s Goddard Space Flight Center/SDO/Joy Ng ANIMATION
On January 13, 2021, NASA’s Solar Dynamics Observatory, or SDO, experienced its first lunar transit of the year when the Moon crossed its view of the Sun. The transit lasted about 30 minutes, between 12:56 and 1:25 a.m. ET. During this time, the Moon happened to cover two of the spacecraft’s fine-guidance sensors, causing its view of the Sun to jitter slightly. SDO recovered a steady view shortly after the transit.
SDO sees lunar transits regularly. Due to its inclined circular orbit 23,000 miles above Earth, the Moon passes between SDO and the Sun between two and five times each year.
SDO captured these images in a wavelength of extreme ultraviolet light. This kind of light is invisible to human eyes, and colorized here in red.