The "head" of whatever this was appeared very large and green and very bright. The trajectory seemed to show that it had some thrust in it, The tail seemed multicolored. I'm terrible at explaining it and it was very fast. I was sitting in the dark with a stray cat and looked up just as it passed nearly overhead and before it was blocked by trees. I gasped and actually ran to see if it kept going.I'm on a hill so it was hard to estimate how high above the horizon it is.