Petr Horálek of NOIRLab photographed a gibbous Moon rising above a ridge at Cerro Pachón in Chile’s Atacama Desert, near major observatories such as the VLT and ALMA. The gibbous phase—when the Moon is more than half illuminated but not full—provides extra night light and enhances views of craters and highlands. The image reveals dark lunar maria, formed by ancient volcanic activity, including Mare Tranquillitatis and Mare Serenitatis. These areas have played notable roles in the history and study of lunar exploration.
Gibbous Moon Hangs Over an Andean Ridge — Space Photo of the Day (Nov. 6, 2025)
Petr Horálek of NOIRLab photographed a gibbous Moon rising above a ridge at Cerro Pachón in Chile’s Atacama Desert, near major observatories such as the VLT and ALMA. The gibbous phase—when the Moon is more than half illuminated but not full—provides extra night light and enhances views of craters and highlands. The image reveals dark lunar maria, formed by ancient volcanic activity, including Mare Tranquillitatis and Mare Serenitatis. These areas have played notable roles in the history and study of lunar exploration.
01:17, 07.11.2025Science
Gibbous Moon Hangs Over an Andean Ridge
Photographer: Petr Horálek (NOIRLab)
When a gibbous Moon rises like a bright, glowing orb above a ridge, the scene feels both timeless and immediate. This striking image was taken from Cerro Pachón in Chile's Atacama Desert, a region that hosts major astronomical facilities such as the Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA).
What is a gibbous Moon?
A gibbous Moon is a lunar phase when more than half of the Moon’s visible surface is illuminated but it is not completely full — or just after full and beginning to wane. This phase is one of the Moon’s brightest stretches, providing extended natural light that enhances night-time visibility.
Why this phase matters to observers
For astronomers and casual stargazers alike, the gibbous phase improves contrast across the lunar surface, making craters, highlands and surface textures easier to see. Across cultures, the gibbous Moon has long symbolized growth, transition and the approach of fullness in cyclical terms.
"The extra reflected light of the gibbous phase reveals the Moon’s dark maria — ancient plains formed when volcanic activity flooded basins long ago."
In this frame you can spot two prominent maria: Mare Tranquillitatis (above left of center) and Mare Serenitatis (left of the Moon’s center). These regions have figured prominently in the history of lunar exploration and remain key targets for scientific study.
This photograph not only showcases a beautiful celestial moment but also points to the important observatories that study the cosmos from Chile’s high deserts. Learn more about lunar landings and the Moon’s features to deepen your appreciation of images like this.