321.

Conjunction of the Moon and Mars The Moon and Mars share the same right ascension, at a separation of 39'. Sat, 16 Sep 2023 at 15:20 EDT (249 days ago) in Virgo

322.

Comet C/2023 P1 (Nishimura) passes perihelion Comet C/2023 P1 (Nishimura) makes its closest approach to the Sun. Sun, 17 Sep 2023 (248 days ago) in Virgo

323.

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. Sun, 17 Sep 2023 at 13:19 EDT (248 days ago) in Virgo

324.

Venus at greatest brightness Venus reaches its greatest brightness in the dawn sky. Mon, 18 Sep 2023 at 08:09 EDT (247 days ago) in Cancer

325.

Neptune at opposition Neptune lies in the opposite direction to the Sun in the sky, making it optimally positioned to be observable for much of the night. Tue, 19 Sep 2023 at 07:09 EDT (246 days ago) in Pisces

326.

Lunar occultation of Antares The Moon will pass in front of Antares (Alpha Scorpii), creating a lunar occultation visible from Japan, Russia, Guam and Northern Mariana Islands. Thu, 21 Sep 2023 at 04:47 EDT (244 days ago) in Scorpius

327.

Mercury at greatest elongation west Mercury is bright and well placed in the dawn sky. Fri, 22 Sep 2023 at 07:27 EDT (243 days ago) in Leo

328.

Mercury at dichotomy Mercury reaches half phase in the dawn sky. Fri, 22 Sep 2023 at 15:26 EDT (243 days ago) in Leo

329.

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. Fri, 22 Sep 2023 at 15:32 EDT (243 days ago) in Sagittarius

330.

September equinox Day and night have equal length, marking the beginning of autumn in the northern hemisphere and spring in the southern hemisphere. Sat, 23 Sep 2023 at 02:46 EDT (242 days ago) in Virgo

331.

Mercury at highest altitude in morning sky Mercury is bright and well placed in the dawn sky. Sat, 23 Sep 2023 (242 days ago) in Leo

332.

Mercury at perihelion Mercury passes its orbit's closest point to the Sun. Sat, 23 Sep 2023 at 14:06 EDT (242 days ago) in Leo

333.

NGC 55 is well placed NGC 55 (mag 8.2), a barred irregular galaxy in Sculptor culminates at around midnight local time. Mon, 25 Sep 2023 (240 days ago) in Sculptor

334.

Conjunction of the Moon and Saturn The Moon and Saturn share the same right ascension, at a separation of 2°38'. Tue, 26 Sep 2023 at 21:29 EDT (239 days ago) in Aquarius

335.

Close approach of the Moon and Saturn The Moon and Saturn pass close to each other. Tue, 26 Sep 2023 at 23:12 EDT (239 days ago) in Aquarius

336.

The Moon at aphelion The Moon recedes to its orbit's furthest point from the Sun, which happens each month around the time of full moon. Wed, 27 Sep 2023 at 02:44 EDT (238 days ago) in Aquarius

337.

47 Tuc is well placed The second brightest globular cluster in the sky, 47 Tuc (NGC 104; mag 4.0), in Tucana culminates at around midnight local time. Wed, 27 Sep 2023 (238 days ago) in Tucana

338.

Daytime Sextantid meteor shower 2023 The Daytime Sextantid meteor shower reaches its peak. Wed, 27 Sep 2023 (237 days ago) in Sextans

339.

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. Wed, 27 Sep 2023 at 20:58 EDT (238 days ago) in Aquarius

340.

Full Moon The Moon reaches full phase and is visible for much of the night. Fri, 29 Sep 2023 at 05:57 EDT (236 days ago) in Pisces