When the sun is not normal to the plane containing the cannisters, the near cannister is shaded from {TAIL ~ direct sunlight} and {HEAD ~ the far cannister} is exposed 
When the sun is not normal to the plane containing the cannisters , the near cannister is shaded from { TAIL ~ direct sunlight } and { HEAD ~ the far cannister } is exposed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH