Rap - If only someone would take the sacrificial knife to YOU. Or certain bits of you, at least, they wouldn't be so damn scarce. You never have had any consideration for your fellow man, you selfish old goat! :p

Not an eclipse, but the next "blue" moon that occurs is the one on the 22nd Aug this year. A blue moon is "the third full moon in a season with four full moons". Due to the vagaries of the lunar cycle, we get 7 "extra" full moons every 19 years. That's your blue moon - the extra one. Or, to put it another way, 12 out of 19 years have one full moon per month; the other seven...

Anyway, if you ever wanted to be particularly emphatic about the infrequency, even unlikelihood, of something happening, you might say “once in a February blue moon”. This will never happen, since, even in a leap year, February's 29 days is shorter than the 29.5 day lunar cycle. February's shortness also means that once per Metonic cycle, it's actually possible for blue moons to occur in both January & March if February has no full moon at all; the last case was in 2018, the next 2037.And NB: still only 13 full moons in the year, since February lacks one!