OCTOBER 2021 OBSERVING Lunar Almanac Northern Hemisphere Sky Chart 16 12 Yellow dots indicate which part of the Moon's limb is tipped the most toward Earth by libration. 31 October 3 MOON PHASES MON SUN NASA / LRO TUE WED THU 3 10 17 24 31 61 +20° NEW MOON October 6 11:05 UT FULL MOON October 20 14:57 UT DISTANCES Perigee FIRST QUARTER October 13 03:25 UT LAST QUARTER October 28 20:05 UT October 8, 17h UT 363,388 km Diameter 32′ 53″ Apogee 405,613 km FAVORABLE LIBRATIONS * Rydberg Crater * Riemann Crater October 24, 15h UT Diameter 29′ 28″ October 3 October 12 * Mercurius Crater October 16 * Vallis Baade 42 OCTOBER 2021 * SKY & TELESCOPE Galaxy Double star October 31 -1 1 2 3 4 Planet location shown for mid-month USING THE NORTHERN HEMISPHERE MAP Go out within an hour of a time listed to the right. Turn the map around so the yellow label for the direction you're facing is at the bottom. That's the horizon. The center of the map is overhead. Ignore the parts of the map above horizons you're not facing. Exact for latitude 40°N. c i n g EQ 4 11 18 25 5 12 19 26 6 13 20 27 7 14 21 28 1 8 15 22 29 FRI 2 9 16 23 30 M39 Zenith SAT M30 CAPRICORNUS 21 β L A C E R T A E g -1 0 1 2 3 4 a Galaxy Double star Variable star Open cluster Diffuse nebula Globular cluster Planetary nebula Galaxy Double star Variable star Open cluster Diffuse nebula Globular cluster Planetary nebula S E E Q Moon Oct 16 U A T α β O R M15 γ C E L I P T I C γ PISCES η δ ε ι ν η α θ β οC E T U S Mira τ α Polaris h t r M2 A Q U A R I U S P E G A S U S G r e a t S q u a r e o f P e g a s u s M31 ANDROMEDA M33 M34 Algol CAS S I OP E I A Double Cluster c a F M52 β γ δ ε Capella AUR I GA Pleiades Hamal A R I E S Jupiter P I SC I S AUS T R I NUS Fomalhaut γ α β γ β TRIANGULUM α β γ α P ERS EUS CAMELOPARDALIS L Y N X δ β C E P H E U S γ +80° +60° o N h α β S C U L P T O R GRUS 3h F a c i n g a F i n c s t α g n i γ α δ β ε ζ E N 0h δ ζ F a 6h ο ε η β µ ζ α θ ε ζ α µ ε α β η Moon Oct 20