Triangular craft with round white lights flying low due east over Sacramento

I was sitting in my spa looking up at the stars. At around 5:58am I could hear a low and rhythmic “wom-wom-wom” sound coming from the west. A triangular(scalene triangle) craft with circular white lights bordering the two leading edges entered my plain of view. 3-4 lights down one leading edge. 4-5 lights down the other leading edge.
Flying directly due east, at a low altitude(500-1000ft). It was clear as day with crisp lines and bright glowing lights. However, it had a definite transparency to it. You could almost see through it. I was able to see it for about 3-5 seconds as it passed overhead and then it was gone.