June 10, 2021 witnessed the first solar eclipse of this calendar year. With the Moon near its farthest point in its orbit from the Earth or apogee, this was an annular eclipse with the Moon only partially covering the disk of the Sun. Unfortunately (at least for me), I did not get to see this eclipse because of low overcast as the partially eclipsed Sun rose at 5:07 AM EDT (09:07 GMT) from the vantage point of my home near the coast, north of Boston. But I did have hopes of maybe catching a glimpse of the Moon’s shadow racing across the disk of the Earth as viewed from space as I did during the solar eclipse (seen as a partial eclipse from my home) back in the summer of 2017 (see “GOES Video of Solar Eclipse – August 21, 2017”).
This map shows the eclipse path of the June 10, 2021 annular solar eclipse as well as the visibility of of the partial eclipse. Click to image to enlarge. (NASA’s Scientific Visualization Studio/Ernie Wright)
As luck would have it, the path of this particular eclipse was largely confined to the high Arctic where geosynchronous weather satellites have a poor view if any. Polar orbiting satellites would have a better vantage point to catch a single snapshot in time of the Moon’s shadow on the Earth if it happened to pass over the shadow during the course of its orbit about the Earth. NASA’s Aqua satellite (part of the polar-orbiting “A-train” of the Earth Observation System) happened to be so lucky and recorded the shadow using MODIS (Moderate Resolution Imaging Spectroradiometer) at about 10:55 GMT as it was approaching the North Pole.
Here is a natural color image of the Moon’s shadow as it approached the North Pole acquired at about 10:55 GMT by MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite. Click on image to enlarge. (NASA/GSFC)
While spectacular, this image only provided a single view in time of the event. A bit more digging revealed that there was a satellite that did capture a sequence of images of the progress of the Moon’s shadow across the globe: NASA’s DSCOVR (Deep Space Climate Observatory). Located 1.60 million kilometers from the Earth at the Sun-Earth L1 Lagrange point, DSCOVR has a unique vantage point to observe the sunlit hemisphere of the Earth. With the spacecraft located 3.31° off the Earth-Sun line and with the Earth’s North Pole tipped about 23° towards the Sun as our home planet nears the summer solstice, DSCOVR was able to observe the Moon’s shadow race across the edge of the Earth’s disk.
Diagram showing the major systems on NASA’s DSCOVR (Deep Space Climate Observatory) satellite. Click on image to enlarge (NASA/GSFC)
Below is a video I produced from a sequence of natural color images created from data return by EPIC (Earth Polychromatic Imaging Camera) – a telescopic camera carried by DSCOVR which provides multispectral views of the Earth at IR, visible and UV wavelengths. The pixel scale of the original images was about 24 kilometers (a factor of about 50 coarser than that provide by the latest geosynchronous weather satellites) with the images taken about every 65 minutes (compared to an imaging rate of up to one image every five minutes from GOES). Despite the resolution and low frame rate, the shadow of the Moon is clearly seen moving across the top of the Earth’s disk. Enjoy!
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Related Reading
“GOES Video of Solar Eclipse – August 21, 2017”, Drew Ex Machina, August 21, 2017, [Post]
very very nice, perfect