Physics Photo of the Week

  Broken Contrail Shadow - Photo by Nasuna Stuart-Ulin Betsy Warren - a PPOW reader - recently sent me a link to a NY Times article (April 15, 2024) that featured a jet's contrail shadowed on the thin clouds below the contrail.  The photo was taken on eclipse day (April 8, 2024) during the partial phase (the Sun was about 90 % blocked by the Moon). The photo has a number of interesting features: The contrail appears to lie below the thin cirrus clouds.  That is just an illusion.  The clouds are thin, and we see the contrail through the thin clouds.  The camera is looking up at the sky; the over-exposed Sun is very far away far above the sky and clouds.  In order for the contrail to cast a shadow the contrail must be above the clouds, between the clouds and theSun.  Notice also that the contrail's shadow appears broken and even doubled in the region where the two shadows overlap.  That is caused by two distinct thin layers of clouds.  The b...