421.

Full Moon The Moon reaches full phase and is visible for much of the night. Mon, 01 Jan 2018 at 21:24 EDT (2,328 days ago) in Gemini

422.

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. Mon, 01 Jan 2018 at 20:55 EDT (2,328 days ago) in Gemini

423.

Mercury at greatest elongation west Mercury is bright and well placed in the dawn sky. Mon, 01 Jan 2018 at 19:51 EDT (2,328 days ago) in Ophiuchus

424.

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. Mon, 01 Jan 2018 at 16:48 EDT (2,328 days ago) in Gemini

425.

Lunar occultation of Aldebaran The Moon will pass in front of Aldebaran (Alpha Tauri), creating a lunar occultation visible from countries and territories including Canada, Greenland, the Contiguous United States and Russia amongst others. Sat, 30 Dec 2017 at 19:35 EDT (2,330 days ago) in Taurus

426.

Close approach of the Moon and Collinder 50 The Moon and Collinder 50 pass close to each other. Sat, 30 Dec 2017 at 16:03 EDT (2,330 days ago) in Taurus

427.

The Rosette Nebula is well placed The Rosette Nebula (C49; mag 9.0) in Monoceros culminates at around midnight local time. Fri, 29 Dec 2017 (2,331 days ago) in Monoceros

428.

Mercury at highest altitude in morning sky Mercury is bright and well placed in the dawn sky. Thu, 28 Dec 2017 (2,331 days ago) in Ophiuchus

429.

The cluster NGC 2232 is well placed The open star cluster NGC 2232 (mag 4.2) in Monoceros culminates at around midnight local time. Thu, 28 Dec 2017 (2,332 days ago) in Monoceros

430.

Mercury at dichotomy Mercury reaches half phase in the dawn sky. Wed, 27 Dec 2017 at 18:29 EDT (2,333 days ago) in Ophiuchus

431.

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, 26 Dec 2017 at 04:20 EDT (2,334 days ago) in Pisces

432.

Ursid meteor shower 2017 The Ursid meteor shower reaches its peak. Fri, 22 Dec 2017 (2,338 days ago) in Ursa Minor

433.

Saturn at solar conjunction Saturn is unobservable as it passes around the far side of the Sun – marking the end of one apparition and the beginning of the next. Thu, 21 Dec 2017 at 15:59 EDT (2,339 days ago) in Sagittarius

434.

December solstice 21 December will be the shortest day of 2017 in the northern hemisphere. Thu, 21 Dec 2017 at 11:23 EDT (2,339 days ago) in Sagittarius

435.

December Leonis Minorid meteor shower 2017 The December Leonis Minorid meteor shower reaches its peak. Tue, 19 Dec 2017 (2,341 days ago) in Leo Minor

436.

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. Mon, 18 Dec 2017 at 21:39 EDT (2,342 days ago) in Sagittarius

437.

The Moon at apogee The Moon recedes to its orbit's furthest point from the Earth, making it appear fractionally smaller than at other times of the month. Mon, 18 Dec 2017 at 20:25 EDT (2,342 days ago) in Sagittarius

438.

New Moon The Moon disappears into the Sun's glare for a few days. Mon, 18 Dec 2017 at 01:31 EDT (2,342 days ago) in Sagittarius

439.

Asteroid 20 Massalia at opposition Asteroid 20 Massalia makes closest approach to the Earth. Fri, 15 Dec 2017 at 23:46 EDT (2,344 days ago) in Taurus

440.

Comae Berenicid meteor shower 2017 The Comae Berenicid meteor shower reaches its peak. Fri, 15 Dec 2017 (2,344 days ago) in Leo