NASA’s Solar Dynamics Observatory (SDO) observed an eclipse of the sun – a strange kind of eclipse that you can only see while orbiting Earth on March 7, 2019.
As shown in the animated Gif below, the black disk of the New Moon passed in front of the sun, reversed course, and did it again:
The eclipse lasted just over 4 hours. As much as 82% of the sun was covered. Technically, that makes it an annular solar eclipse, not total. At maximum, an annulus or “ring of fire” completely surrounded the Moon.
The strange “double-dip” motion of the Moon across the sun is a result of orbital mechanics. Both SDO and the Moon are orbiting Earth, but at different speeds. SDO’s velocity of ~3 km/s is faster than the Moon’s velocity of 1 km/s. SDO thus overtakes the Moon first in one direction, then the other, during the long eclipse.
High-resolution images of the eclipse reveal that the Moon is not perfectly smooth. The little bumps and irregularities you see are lunar mountains backlit by solar plasma:
Such images can then be used to correct SDO data for instrumental effects and sharpen images of the sun even more than before.
Do we have two suns? Or how come weren’t we able to see this solar eclipse from below?
