This amazing picture is in fact pollen. It was obtained from a white flower outside of Caltech’s Earl M. Jorgensen Laboratory (behind the sign) at 7:05 PST 05/09/2019.
The flower and location of where the sample was obtained.

Using reverse google image search, this flower was determined to be
Romneya , commonly known as the Matilija poppy. It is native to California and Northern Mexico!!!
#caltechbi1