The Moon’s appearance on any given night is determined by its position within its 29.5-day orbit around Earth and relative to the Sun. The angle at which sunlight illuminates the Moon’s surface, as viewed from our planet, determines the visible shape, known as the lunar phase. To determine the exact look of the Moon on March 31, 2020, we must examine the specific astronomical data for that date, including its illumination, distance, and place in the lunar cycle.
The Specific Lunar Phase
On March 31, 2020, the Moon was in the Waxing Crescent phase, moving rapidly toward the First Quarter phase. This meant that less than half of the lunar disk was illuminated by the Sun, specifically showing an illumination percentage of approximately 47%. Visually, the Moon appeared as a slender, glowing curve on the right side, with the remaining portion of the disk barely visible or completely dark. The term “waxing” describes the illuminated area growing larger each night as it progresses toward the Full Moon.
The Moon was located approximately 386,018 kilometers from Earth on this date. This distance is relatively close to the average, but the Moon was actively moving toward its perigee, the closest point in its orbit to Earth, set to occur about a week later. This movement meant the Moon’s apparent size was slightly larger than average. The illuminated crescent offered excellent viewing of lunar surface features like craters and mountains along the terminator, the dividing line between light and shadow.
Visibility and Timing
For viewers across much of the globe, the Moon was best observed in the afternoon and early evening hours. The Moon rose around mid-morning, approximately 10:47 AM local time, and was already high in the sky by late afternoon. Because it was a Waxing Crescent phase, the Moon followed the Sun across the sky and became visible earlier in the day than later phases like the Full Moon. It reached its highest point in the sky during the mid-to-late afternoon, making it a “daytime Moon” for a significant portion of its transit.
The Moon set well after midnight, at approximately 1:00 AM local time. This provided a good window for observation shortly after sunset, as the contrast between the bright crescent and the darkening sky improved visibility. Unlike a Full Moon, which rises near sunset, the Waxing Crescent was already well above the horizon when the Sun went down. It was visible toward the western horizon in the early evening, a classic position for this phase.
Position in the Lunar Cycle
The Moon was in the waxing half of its synodic cycle on March 31, 2020, meaning the illuminated portion was expanding daily. It had passed the New Moon phase about seven days prior, which occurred on March 24, 2020.
The next major phase was the Full Moon, which occurred a little over a week later, on April 7th or 8th, 2020. The apparent change in the Moon’s shape is purely an effect of geometry, as our perspective from Earth changes continually, revealing a different portion of the sunlit hemisphere each night.