Waxing Crescent

The Waxing Crescent covers the stretch right after New Moon, when a thin sliver of light along one edge of the Moon grows visibly night by night, climbing from barely-there illumination toward the half-lit point of First Quarter. "Waxing" simply means growing — the opposite of "waning," which describes the shrinking half of the cycle two weeks later.

This is also when you can sometimes spot earthshine, also called "the old moon in the new moon's arms" — a faint glow across the crescent's dark portion, caused by sunlight reflecting off Earth, bouncing to the Moon, and reflecting back to your eye a second time. It's most visible a few days into the waxing crescent, low in the west shortly after sunset, and it's a genuinely observable, physically real effect rather than an optical illusion.

Because the crescent appears low in the western sky in early evening twilight, this is often the trickiest phase to spot for casual skywatchers — it sets not long after the Sun and can be lost in bright evening light or blocked by a western horizon obstruction (buildings, hills, trees) even on a clear night.

The crescent's curved shape always has its points (the "horns") facing away from the Sun's position below the horizon — a reliable way to tell which direction is roughly west-ish relative to the Moon at any given moment during this phase.

This stretch of the cycle lasts a little under a week, covering roughly days 1 through 6-7 of the lunation counted from New Moon — visibly the fastest-changing phase night to night in terms of percentage growth relative to its own small starting size, even though the absolute rate of illumination change (in percentage points per day) is fairly steady across the whole waxing half of the cycle.

The crescent shape itself is produced by a genuinely three-dimensional effect worth visualizing: you're seeing the curved edge of a sphere that's only partially lit, viewed from an angle where the terminator (the day-night line on the Moon's surface) appears as a curve rather than a straight line — the same basic geometry that produces First Quarter's straight terminator once the Moon reaches the 90-degree viewing angle.

Ancient and medieval astronomers across many cultures used the crescent Moon's reappearance after New Moon as a practical calendar marker, since it's the first visually confirmable sign that a new lunar month has begun — several lunar and lunisolar calendars still in active use today, including the Islamic calendar, formally define the start of a new month by the crescent's first visual sighting rather than a purely mathematical calculation.

This opening phase of the lunation carries a genuine sense of freshness for many observers — the first visible sign, after New Moon's darkness, that a new cycle is underway, distinct from the anticipation that builds later toward Full Moon.

A simple phone tripod adapter can turn even a basic smartphone into a workable tool for a first attempt at photographing this thin, low-hanging sliver.