Beautiful! Just observed a spectacular, on-time depletion burn by tonight's Delta launch vehicle. Just as Ron described, it started as a faint plume just as the vehicle came out of shadow, then rapidly blossomed into a bright, milky plume curving as the booster tumbled. Almost directly overhead, too. Managed to track several points of light for a short period following the burn, but quickly lost them to street light pollution. Thank you Ron for the timely data - that was terrific to see. -Terry Pritchard Orangeville, Ontario, Canada N43.925 W80.116