The best moon phase for stargazing is the new moon, when the Moon sits close to the Sun in the sky and adds no light to the night. The week around the new moon, from the last waning crescent to the first thin waxing crescent, gives the darkest nights of the month.
Why is the new moon best for stargazing?
The new moon is best because moonlight, scattered by the atmosphere, brightens the whole sky and hides faint stars, the Milky Way and faint meteors. At new moon the Moon rises and sets with the Sun, so none of that light reaches the night sky.
The full moon is the opposite case. At an apparent magnitude of about −12.7, the full moon is by far the brightest object in the night sky. Most full moons at mid-latitudes light the ground at 0.05–0.2 lux, enough to cast shadows, and the glow spreads across the whole sky. A naturally dark sky, with no Moon and no artificial light, is lit only by faint airglow, zodiacal light and starlight.
What moonlight hides first:
- The Milky Way: its faint glow disappears from a moonlit sky even at dark sites.
- Faint galaxies and nebulae: objects that need a dark background drop below what the eye can pick out.
- Faint meteors: only the brighter meteors of a shower stay visible.
- Faint stars: the number of stars you can count falls sharply.
The next new moon is on . Plan a dark-sky trip for the few nights on either side of that date.
Which nights around the new moon are dark?
The darkest nights run from a few days before to a few days after the new moon, because a thin crescent sets soon after dusk or rises shortly before dawn. Our lunar engine finds that at 40° latitude about 5 nights per lunar cycle are completely moon-free during full darkness.
| Phase | Where the Moon is at night | Dark sky for stargazing |
|---|---|---|
| New moon | Up only in daytime, near the Sun | All night |
| Waxing crescent | Low in the west after sunset; sets in the evening | After the crescent sets |
| First quarter | Sets around midnight | After midnight |
| Waxing gibbous | Sets after midnight, toward dawn | Short window before dawn |
| Full moon | Up from sunset to sunrise | None |
| Waning gibbous | Rises in the evening | Short window after dusk |
| Last quarter | Rises around midnight | Before midnight |
| Waning crescent | Rises a few hours before sunrise | Most of the night |
The dark hours shift each day because the Moon rises about 50 minutes later on average from one day to the next. The guide to why the moon rises later each day explains the cause. A waxing crescent leaves the sky dark from mid-evening, and a waning crescent keeps it dark until the small hours.
- Completely moon-free nights per cycle
- about 5
- Nights at least 75% moon-free
- about 10
- Nights with the Moon up from dusk to dawn
- about 5
- Latitude used
- 40° (counted by our lunar engine)
The nights with the Moon up from dusk to dawn cluster around the next full moon. The last quarter moon is a useful compromise: the evening stays dark until the Moon rises around midnight.
What is tonight’s dark window?
Tonight’s dark window is the stretch of astronomical night, when the Sun is more than 18° below the horizon, during which the Moon is also below the horizon. The tool at the top of this page calculates it for your location.
The tool works in three steps:
- Astronomical darkness: it finds when the Sun sinks 18° below the horizon in the evening and when it climbs back to 18° before dawn. Between those times, twilight no longer brightens the sky.
- Moon up or down: it finds every moonrise and moonset during that stretch of darkness.
- Longest moon-free window: it reports the longest period when the sky is fully dark and the Moon is down, plus the Moon’s lit fraction.
At high latitudes in summer there may be no dark window at all. North of about 48.5°N, which includes London, Paris and Vancouver, the Sun never sinks 18° below the horizon around the June solstice, so twilight lasts all night. The same happens south of about 48.5°S around the December solstice.
To see the Moon’s rise and set times, its direction and its phase for your location, check the moon tonight. For any city, the moonrise and moonset times pages give the full daily table.
How does the Moon affect meteor showers?
Moonlight hides faint meteors, so a meteor shower peak near the new moon shows far more meteors than a peak near the full moon. The American Meteor Society rates each peak by lunar conditions, from “little or no moonlight interference” to “significant interference while the Moon is above the horizon.”
Meteor shower peaks fall on about the same dates every year, such as the Perseids in mid-August and the Geminids in mid-December. The Moon’s phase on those dates changes from year to year. To judge a peak:
- Check the phase on the peak night. The moon phase calendar shows the phase for every date.
- Watch the Moon’s hours. A last quarter moon rises around midnight, so the hours before it rises stay dark.
- Watch after the Moon sets. A waxing crescent or first quarter moon sets in the evening or around midnight, leaving the hours before dawn dark.
A peak within a few days of the new moon on will have dark skies for most of the night.
When can you see the Milky Way core?
The bright core of the Milky Way, toward the constellation Sagittarius, is visible in full darkness from about March to October at mid-northern latitudes, and best from May to August. The core needs both a moon-free sky and the right season.
Our lunar engine tracked the galactic center through the year:
- At 40°N (New York, Madrid, Beijing): the core clears 10° altitude during full darkness from late February, briefly before dawn, to early October, briefly after dusk. The longest views come in June and July, but the core never climbs higher than about 21°.
- At 50°N to 52°N (Kraków, London): the core barely reaches about 10° above the southern horizon, so a low, clear southern view is essential.
- At 34°S (Sydney, Cape Town, Santiago): the core is visible from February to November and passes almost overhead from about April to August, far higher than from northern sites.
Pick the new-moon week inside that season. A Milky Way core photo needs the core above the horizon, the Sun more than 18° below it and the Moon down, all at once.
How much does light pollution matter?
Light pollution can matter as much as the Moon, because a bright town washes out the sky every night of the month. The Bortle scale rates sky darkness in nine classes, from Class 1 (excellent dark site) to Class 9 (inner-city sky).
| Bortle class | Sky | Naked-eye limiting magnitude | Milky Way |
|---|---|---|---|
| 1–3 | Dark sites | about 7.6–8.0 at Class 1 | Highly structured |
| 4–5 | Rural edges and suburbs | about 5.6–6.0 at Class 5 | Visible but weakened, little detail |
| 6–7 | Bright suburbs | – | Only near the zenith, or gone |
| 8–9 | Cities | 4.0 or less at Class 9 | Invisible |
Moonlight and light pollution add together. A full moon over a suburban sky leaves only the brightest stars, while a new moon at a Class 1–3 site shows the Milky Way with complex structure.
When is the Moon itself the best target?
The first quarter moon is the best phase for looking at the Moon itself, because the line between day and night crosses the middle of the face we see. Along that line, the terminator, long shadows make craters and mountains stand out.
NASA’s observing guide says the terminator “is ideal for seeing lunar craters and mountains since very long shadows heighten the contrast of the features.” The first quarter moon is also high in the evening sky, which is why International Observe the Moon Night is usually held near that phase.
At full moon the Sun shines straight down on the side facing Earth, so craters cast almost no shadows and the surface looks flat and bright. Even binoculars show more relief near first quarter and in the waxing gibbous days that follow than at full moon.
Can you see planets near the Moon?
You can see bright planets near the Moon about once a month each, because the Moon and the planets all travel close to the ecliptic. The Moon’s orbit is tilted only 5.14° to the ecliptic, and the Moon circles the sky in 27.3 days, so it passes each bright planet once per orbit.
- Bright planets cut through moonlight: Venus and Jupiter stay easy to see even beside a bright Moon, and Mars and Saturn usually remain visible.
- The Moon is a pointer: a crescent or gibbous Moon next to a planet makes the planet easy to find for beginners.
- Close pairs make good photos: a thin crescent near Venus at dusk or dawn is a simple target for a phone camera.
Planets, the Moon and bright double stars do not need the new moon, so the bright half of the lunar cycle is a good time for them.