Occlusions are any kind of blocking off. If I step in front of you in line at the coffee shop, I have occluded you and also been a jerk. Go ahead, kick me in the shin. 

This morning, the Moon is stepping in front of Mars. This occlusion, Mars-and-the-Moon, occurs twice a year. It's kind of like an eclipse, but an eclipse is a specific kind of occlusion where a shadow is cast. But here there's no shadow. Just Mars briefly hidden behind the Moon's back.

You'll be in the best position to see the end of the occlusion in the Pacific time zone. With a clear low view in the southeast, you'll see Mars pop back out from behind the Moon's back. 

Enjoy the trip Mars.