Dec. 9, 2014, 1 a.m.
|| Dial-A-Moon || New: Click on the image to download a high-resolution version with labels for craters near the terminator. The data in the table for the entire year can be downloaded as a JSON file or as a text file.The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2015, at hourly intervals. Until the end of 2015, the initial Dial-A-Moon image will be the frame from this animation for the current hour.More in this series:Moon Phase and Libration GalleryLunar Reconnaissance Orbiter (LRO) has been in orbit around the Moon since the summer of 2009. Its laser altimeter (LOLA) and camera (LROC) are recording the rugged, airless lunar terrain in exceptional detail, making it possible to visualize the Moon with unprecedented fidelity. This is especially evident in the long shadows cast near the terminator, or day-night line. The pummeled, craggy landscape thrown into high relief at the terminator would be impossible to recreate in the computer without global terrain maps like those from LRO.The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it s. During New Moon here, the Earth is full as viewed from the Moon. || Crater labels. The labels appear when the center of the crater is within 20 degrees of the terminator (the day-night line). They are on the western edge of the crater during waxing phases (before Full Moon) and to the east during waning phases. The frames include an alpha channel. || Waxing crescent. Visible toward the southwest in early evening. || First quarter. Visible high in the southern sky in early evening. || Waxing gibbous. Visible to the southeast in early evening, up for most of the night. || Full Moon. Rises at sunset, high in the sky around midnight. Visible all night. || Waning gibbous. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise. || Third quarter. Rises around midnight, visible to the south after sunrise. || Waning crescent. Low to the east before sunrise. || New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many lunar and lunisolar calendars.