Envisat ASAR image of Campos Basin taken November 22, 2011. Surface winds too strong to reliably detect thin oil slicks. Bright spots are vessels and oil platforms. Image courtesy European Space Agency.
Today's Envisat ASAR satellite radar image of the Campos Basin, covering the location of the Chevron / Transocean oil spill, shows no sign of an oil slick. It was taken at about 9:30 am local time.
However, the wind speed was fairly strong in the area at the time. According to the satellite scatterometer data collected by the ASCAT system, surface winds were blowing at 15-25 knots (8-13 meters per second). This is strong enough to overwhelm very thin oil slicks (the optimum wind speed for detecting slicks on radar images is about 3 - 10 meters per second)