401.

Conjunction of the Moon and Venus The Moon and Venus share the same right ascension, at a separation of 3°38'. Sat, 09 Dec 2023 at 11:54 EDT (203 days ago) in Virgo

402.

σ-Hydrid meteor shower 2023 The σ-Hydrid meteor shower reaches its peak. Tue, 12 Dec 2023 (200 days ago) in Hydra

403.

New Moon The Moon disappears into the Sun's glare for a few days. Tue, 12 Dec 2023 at 18:33 EDT (200 days ago) in Ophiuchus

404.

The Large Magellanic Cloud is well placed The Milky Way's dwarf companion, the Large Magellanic Cloud (LMC; mag 0.9), in Dorado culminates at around midnight local time. Tue, 12 Dec 2023 (200 days ago) in Dorado

405.

The Moon at perihelion The Moon passes its orbit's closest point to the Sun, which happens each month around the time of new moon. Wed, 13 Dec 2023 at 10:39 EDT (199 days ago) in Sagittarius

406.

Conjunction of the Moon and Mercury The Moon and Mercury share the same right ascension, at a separation of 4°21'. Thu, 14 Dec 2023 at 00:20 EDT (198 days ago) in Sagittarius

407.

Geminid meteor shower 2023 The Geminid meteor shower reaches its peak. Thu, 14 Dec 2023 (198 days ago) in Gemini

408.

The Orion Nebula is well placed The Orion Nebula (M42; mag 4.0) culminates at around midnight local time. Fri, 15 Dec 2023 (197 days ago) in Orion

409.

The Running Man cluster is well placed The Running Man cluster NGC 1977 (mag 4.2) in Orion's sword culminates at around midnight local time. Fri, 15 Dec 2023 (197 days ago) in Orion

410.

Comae Berenicid meteor shower 2023 The Comae Berenicid meteor shower reaches its peak. Sat, 16 Dec 2023 (196 days ago) in Leo

411.

The Moon at perigee The Moon makes its monthly closest approach to the Earth, making it appear fractionally larger than at other times of the month. Sat, 16 Dec 2023 at 13:52 EDT (196 days ago) in Capricornus

412.

Conjunction of the Moon and Saturn The Moon and Saturn share the same right ascension, at a separation of 2°28'. Sun, 17 Dec 2023 at 17:01 EDT (195 days ago) in Aquarius

413.

Close approach of the Moon and Saturn The Moon and Saturn pass close to each other. Sun, 17 Dec 2023 at 18:44 EDT (195 days ago) in Aquarius

414.

Lunar occultation of Neptune The Moon will pass in front of Neptune, creating a lunar occultation visible from Australia. Tue, 19 Dec 2023 at 09:16 EDT (193 days ago) in Pisces

415.

Moon at First Quarter The Moon reaches first quarter phase – appearing high in the sky at sunset and setting in the west at around midnight. Tue, 19 Dec 2023 at 13:39 EDT (193 days ago) in Pisces

416.

December Leonis Minorid meteor shower 2023 The December Leonis Minorid meteor shower reaches its peak. Wed, 20 Dec 2023 (192 days ago) in Leo Minor

417.

Mercury at perihelion Mercury passes its orbit's closest point to the Sun. Wed, 20 Dec 2023 at 12:04 EDT (192 days ago) in Sagittarius

418.

Asteroid 4 Vesta at opposition Asteroid 4 Vesta makes closest approach to the Earth. Thu, 21 Dec 2023 at 16:34 EDT (191 days ago) in Orion

419.

December solstice 22 December will be the shortest day of 2023 in the northern hemisphere. Thu, 21 Dec 2023 at 22:24 EDT (191 days ago) in Sagittarius

420.

Close approach of the Moon and Jupiter The Moon and Jupiter pass close to each other. Fri, 22 Dec 2023 at 07:31 EDT (190 days ago) in Aries