SDO captured this image of Earth and moon as they were transiting the sun together. The edge of Earth is visible near the top of the frame and on the left, the moon’s edge is also perfectly seeable.
You may notice that Earth’s outline looks fuzzy, while the moon’s is crystal clear. This is because, while the planet itself completely blocks the sun's light, Earth’s atmosphere is an incomplete barrier, blocking different amounts of light at different altitudes.
On the other hand, the moon has no atmosphere, so during the transit we can clearly see the crisp edges of the moon's horizon.
This image was taken in extreme ultraviolet wavelengths of 171 angstroms. Though this light is invisible to our eyes, it is typically colorized in gold.
article reference:- nasa.gov