If it took out the moon say bye to tides, astrology and any superstition regardsing our moon, which btw is already moving away from us at about a centimeter a year or so.
A 1000-foot object hitting the moon, reminds me of that comet that hit Jupiter in 1995, a bit close to home IMO. The debris will enter Earth's atmosphere afterwards; you can say bye VFR for a number of days...
Heck, let's consider a linear and abolutely irrelevent idea: if the objects previously mentioned were periodic, then by circa 2050, we could have been hit. Likely by a much smaller target.
The meaning of life is curiosity; we were put on this planet to explore opportunities.