The Moon

by Dominic Ford, Editor
Last updated: 24 Mar 2020

The Moon is 11 days old, waxing gibbous, and is approaching full moon. From Seattle, it is visible in the evening sky, becoming accessible around 19:36 (PDT), 9° above your south-eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 23:05, 21° above your southern horizon. It will continue to be observable until around 02:49, when it sinks below -2° above your south-western horizon.

13 Sep 2021  –  Moon at First Quarter
20 Sep 2021  –  Full Moon
28 Sep 2021  –  Moon at Last Quarter
06 Oct 2021  –  New Moon
The Moon

The Moon at First Quarter. Simulated image courtesy of Tom Ruen.

The Moon is the Earth's only natural satellite, orbiting it once every 27.3 days, at a distance of 380,000 km (0.00254 astronomical units).

It has almost exactly the same angular size as the Sun – roughly half a degree – a coincidence which means it can occasionally completely cover the Sun's disk to generate a total solar eclipse, but with so little margin that the geometry has to be absolutely exact.

The Moon is the only heavenly body on which surface features can be resolved by the unaided eye. Its mottled pattern of light and dark areas represent two distinct types of terrain. The dark areas are called maria – originally so named because they were thought to be oceans of water, but they are now known to be vast flat volcanic planes. Between the maria, the lighter colored terrain is considerably rougher and more mountainous – the lunar highlands.

To bring the Moon's heavily cratered surface into view, nothing more expensive than a cheap pair of binoculars is needed.

Dates of the Moon's phases

The table below lists the phases of the Moon in 2021, computed from NASA's DE430 planetary ephemeris. To show events in other years, use the control below.

Change year

Timezone

The Moons phases in 2021

Date Event Moon's declination
Date Event Moon's declination
06 Jan 2021 01:37 PSTMoon at Last Quarter1°58'S
12 Jan 2021 21:01 PSTNew Moon24°19'S
20 Jan 2021 13:02 PSTMoon at First Quarter8°06'N
28 Jan 2021 11:16 PSTFull Moon21°50'N
04 Feb 2021 09:37 PSTMoon at Last Quarter13°58'S
11 Feb 2021 11:06 PSTNew Moon18°11'S
19 Feb 2021 10:48 PSTMoon at First Quarter19°03'N
27 Feb 2021 00:17 PSTFull Moon12°55'N
05 Mar 2021 17:30 PSTMoon at Last Quarter22°40'S
13 Mar 2021 02:22 PSTNew Moon7°24'S
21 Mar 2021 07:41 PDTMoon at First Quarter24°58'N
28 Mar 2021 11:48 PDTFull Moon1°01'N
04 Apr 2021 03:03 PDTMoon at Last Quarter25°21'S
11 Apr 2021 19:32 PDTNew Moon5°00'N
19 Apr 2021 23:59 PDTMoon at First Quarter23°56'N
26 Apr 2021 20:31 PDTFull Moon11°02'S
03 May 2021 12:50 PDTMoon at Last Quarter21°16'S
11 May 2021 12:01 PDTNew Moon16°18'N
19 May 2021 12:13 PDTMoon at First Quarter16°45'N
26 May 2021 04:13 PDTFull Moon20°40'S
02 Jun 2021 00:25 PDTMoon at Last Quarter12°03'S
10 Jun 2021 03:54 PDTNew Moon23°50'N
17 Jun 2021 20:54 PDTMoon at First Quarter5°53'N
24 Jun 2021 11:39 PDTFull Moon25°26'S
01 Jul 2021 14:11 PDTMoon at Last Quarter0°14'S
09 Jul 2021 18:17 PDTNew Moon25°24'N
17 Jul 2021 03:11 PDTMoon at First Quarter6°12'S
23 Jul 2021 19:36 PDTFull Moon23°49'S
31 Jul 2021 06:16 PDTMoon at Last Quarter11°48'N
08 Aug 2021 06:51 PDTNew Moon20°30'N
15 Aug 2021 08:20 PDTMoon at First Quarter17°12'S
22 Aug 2021 05:01 PDTFull Moon16°21'S
30 Aug 2021 00:13 PDTMoon at Last Quarter21°32'N
06 Sep 2021 17:52 PDTNew Moon10°43'N
13 Sep 2021 13:39 PDTMoon at First Quarter24°34'S
20 Sep 2021 16:54 PDTFull Moon5°02'S
28 Sep 2021 18:57 PDTMoon at Last Quarter26°04'N
06 Oct 2021 04:06 PDTNew Moon1°35'S
12 Oct 2021 20:25 PDTMoon at First Quarter25°45'S
20 Oct 2021 07:56 PDTFull Moon7°41'N
28 Oct 2021 13:05 PDTMoon at Last Quarter23°29'N
04 Nov 2021 14:15 PDTNew Moon13°54'S
11 Nov 2021 04:46 PSTMoon at First Quarter20°00'S
19 Nov 2021 00:57 PSTFull Moon19°04'N
27 Nov 2021 04:28 PSTMoon at Last Quarter14°31'N
03 Dec 2021 23:44 PSTNew Moon23°12'S
10 Dec 2021 17:36 PSTMoon at First Quarter9°00'S
18 Dec 2021 20:35 PSTFull Moon25°41'N
26 Dec 2021 18:24 PSTMoon at Last Quarter1°52'N

Share

Follow

Seattle

Latitude:
Longitude:
Timezone:

47.61°N
122.33°W
PDT

Color scheme