On Thursday, March 7, NASA's Solar Dynamics Observatory (SDO) recorded a solar eclipse visible only from Earth's orbit.
During the eclipse, which lasted just over four hours, 82% of the Sun was covered. Such an eclipse, when the Moon does not completely cover the Sun and is surrounded by its ring of fire, is called annular.
As you can see, the dark disc of the Moon in the new moon phase passes in front of the Sun, then stops and again passes back and forth. This unusual effect is the result of orbital mechanics. Both SDO and the Moon revolve around the Earth, but at different speeds. SDO's speed is about 3 km / s and the Moon's speed is 1 km / s. Thus, SDO overtakes the moon, first in one direction and then in another.
The high resolution images show that the Moon is not quite smooth. Its wavy edge is lunar mountains illuminated by solar plasma. Such crisp footage is of practical value to the SDO scientific team in helping to tune the telescope and improve image quality.