Good
Sky brightness now
?
18.40mag/arcsec²
naked eye to 4.3
LinesConstellationsLabels
Tonight01:01 CDT
Good
Worth going out. The window opens at 22:21.
Held back by light pollution, nothing much is in the way.
Score
Best window
?22:21until 03:21 · 5 hGrade the night ›
Moon
True dark
?5 h 36 min0% moonlessGrade the night ›
20:0021:0022:0023:0000:0001:0002:0003:0004:0005:0006:00NOW
MoonMoonMW coreMilky Way coreAstronomical nightBest window01:01 · 57 this half-hour
TonightWhyOther nightsWhat's upWhere to goComing up
A night is not one thing. Grade the window you actually have.
21:00 – 22:30
Marginal
Thin, but you would see something. Bright targets only.
Up in that window
?
Vega83° up · SESummer Triangle67° up · ESEAlbireo67° up · SEDeneb63° up · ENEAltair49° up · SEArcturus47° up · WSW
Best moment in the window is 22:21, held back by light pollution.
6.7Bortle
Suburban / urban transition
?
18.82
mag/arcsec²
?
4.6
naked eye, no Moon
?
The whole sky glows grayish. Clusters are faint smudges.
Which way is darkest
?
NESW
Darkest horizon
NW
Point a camera NW and put your back to the glow. The worst of it is SE. That is Madison, 0 km away.
What is causing it
Madison0 km SE97%
Modeled from population data, not satellite radiance. Cross-validated against published sky-quality readings: RMSE 0.49 mag/arcsec² out of sample: 0.31 at rural sites, 0.69 in cities, worst case 1.2.
Known bias: within \~15 km of a mid-size city it reads about one Bortle class too dark. If that is you, assume the real sky is worse than this.
☀Sunset20:21
◐Civil twilight ends20:50
◑Nautical twilight ends21:31
●Astronomical night22:16 – 03:52
◒Nautical twilight begins04:37
☀Sunrise05:46
Waning Gibbous
87% lit · rises 21:44 · sets –
Of your 5 h 36 min of true dark, 0% is moonless.