As the lunar cycle draws to a close, the night sky is seeing a significant decrease in moonlight. On Monday, April 13, 2026, the Moon is in its Waning Crescent phase, appearing as a thin, delicate sliver in the sky.
Tonight’s Lunar Outlook
According to NASA’s Daily Moon Guide, only 21% of the Moon’s surface will be illuminated tonight. Because we are just a few days away from the New Moon—the point at which the Moon is positioned between the Earth and the Sun and becomes virtually invisible—the visible portion of the Moon will continue to shrink each night.
What to look for through the lens
For casual observers using only the naked eye, visibility will be limited. The most prominent feature likely to be spotted is the Aristarchus Plateau. However, for those using binoculars or a telescope, the view expands significantly, allowing for the observation of the Grimaldi Basin alongside the plateau.
Understanding the Lunar Cycle
The changing appearance of the Moon is not due to the Moon itself changing shape, but rather the shifting angle of sunlight hitting its surface as it orbits Earth. This cycle, known as the lunar cycle, takes approximately 29.5 days to complete.
During this orbit, the Moon passes through eight distinct stages:
- New Moon: The side facing Earth is dark, making the Moon invisible.
- Waxing Crescent: A small sliver of light begins to appear on the right side (in the Northern Hemisphere).
- First Quarter: Half of the Moon is illuminated on the right side.
- Waxing Gibbous: Most of the Moon is lit, but it is not yet a full circle.
- Full Moon: The entire face of the Moon is illuminated.
- Waning Gibbous: The illumination begins to decrease from the right side.
- Third Quarter: Half of the Moon is illuminated on the left side.
- Waning Crescent: A final thin sliver of light remains on the left before the cycle resets.
Looking Ahead
If you are waiting for a bright, fully illuminated sky, you will have to wait a little longer. The next Full Moon is projected to occur on May 1, 2026, marking the beginning of a month that will feature two full moons.
Summary: On April 13, the Moon is in a waning phase with only 21% illumination, offering limited visibility for observers until the next Full Moon arrives on May 1.
