Archive for June 6, 2022

06/06/2022 – Ephemeris – In June we spend our evenings in the twilight zone

June 6, 2022 Comments off

This is Ephemeris for Monday, June 6th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57. The Moon, 1 day before first quarter, will set at 2:28 tomorrow morning

We spend our evenings after sunset during the months of June and July, pretty much in the twilight zone. Actually, it’s just twilight. There are three twilight periods: Civil, Nautical and Astronomical. In the evening, civil twilight lasts from sunset to when the Sun drops to 6 degrees below the horizon. The scene around is still quite bright, but car headlights still need to be on. Nautical twilight lasts until the Sun is 12 degrees below the horizon. Bright stars and the horizon are visible for sextant use. After that is astronomical twilight until the Sun is 18 degrees below the horizon, when the stars become more and more numerous. After that it’s officially dark, Moon permitting. This time of year we’re lucky to get three and a half hours of darkness.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.


Twilight example for June 6, 2022

Daylight, twilight, and dark example for June 6, 2022. This graph is centered on midnight. Light blue is daylight, while the three darker shades of blue denote the three twilight periods of civil, nautical and astronomical. The yellow lines show when the Sun, Moon and planets are visible. Dark of night is relegated only to the morning hours, thanks to the season, daylight saving time and our location 43 minutes west of our standard time meridian. The chart is produced by the app Cartes du Ciel (Sky Charts).

Categories: Concepts, Observing, Twilight