Active: December 4—17; Maximum: December 13, 23h30m UT (λ⊙ = 262.2°); ZHR = 120;
Radiant: α = 112°, δ = +33°; Radiant drift: see Table 6;
V∞ = 35 km/s; r = 2.6;
TFC: α = 87°, δ = +20° and α = 135°, δ = +49° before 23h local time,
α = 87°, δ = +20° and α = 129°, δ = +20° after 23h local time (β > 40° N);
α = 120°, δ = −3° and α = 84°, δ = +10° (β < 40° N).
IFC: α = 150°, δ = +20° and α = 60°, δ = +40° (β > 20° N);
α = 135°, δ = -5° and α = 80°, δ = 0° (β < 20° N).
One of the finest, and probably the most reliable, of the major annual showers presently observable, whose peak this year falls perfectly for new Moon. Well north of the equator, the radiant rises about sunset, reaching a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. It culminates near 02h. Even from more southerly sites, this is a splendid stream of often bright, medium-speed meteors, a rewarding event for all observers, whatever method they employ. The peak has shown slight signs of variability in its rates and timing in recent years, with the more reliably-reported maxima during the past two decades (HMO, p. 171) all having occurred within λ⊙ = 261.5° to 262.4°, 2012 December 13, 07h to December 14, 04h UT. Near-peak rates usually persist for almost a day, so much of the world has the chance to enjoy something of the Geminids’ best. Some mass-sorting within the stream means fainter telescopic meteors should be most abundant almost a day ahead of the visual maximum, with telescopic results indicating such meteors radiate from an elongated region, perhaps with three sub-centres. Further results on this topic would be useful.