Small, bright-white light disappears into another larger, diffuse light (at sunset).

I am writing to you today to document what happened to me as a child (about 14yr of age).  
It was a mostly sunny and warm day in summer.  I climbed onto the top of my Dad's camper and was lying on my back, watching the sunset.  
I noticed a small, bright, white, light moving west to east across the sky at a mediun, steady pace.  Within seconds, a second light appeared to the east of, and slightly above, the first.  This light was round and white, but many times larger than the first, and diffuse.  
The first light continued moving east until it was directly below the second.  There was a brief hesitation, then the first light shot straight up into the second.  When the two lights came together, they both instantly disappeared.