  We present a daytime thermal image of Europa taken with the Atacama Large
Millimeter Array. The imaged region includes the area northwest of Pwyll
Crater, which is associated with a nighttime thermal excess seen by the Galileo
Photopolarimeter Radiometer and with two potential plume detections. We develop
a global thermal model of Europa and simulate both the daytime and nighttime
thermal emission to determine if the nighttime thermal anomaly is caused by
excess endogenic heat flow, as might be expected from a plume source region. We
find that the nighttime and daytime brightness temperatures near Pwyll Crater
cannot be matched by including excess heat flow at that location. Rather, we
can successfully model both measurements by increasing the local thermal
inertia of the surface.
