Current Lunar Phases Viewed From Four Sides

Lunar Hemispheric Phase Explorers - 1500×1500-pixel HD Edition Current Lunar Phases as Viewed From Above the Four Hemispheres Program and Graphics by Jay Tanner - 2025
Current Geocentric Lunar Coordinates, Distance and Phase Based on the NASA/JPL DE405 Ephemeris Model Working Date UD = 2025 May 04 - Sun Working Time UT = 13:33:21 Astronomical JD TT = 2460800.06569090 Right Ascension = 9.1811624 hr = 09h 10m 52.19s Declination = +19.883358 deg = +19° 53' 00.09" Distance = 388121.5 km = 241167.5 mi Phase Angle = 89.849 deg REFRESH Page to Update Statistics and Images to Current Date and Time CLICK On Any Hemispheric Image For a Full 1500×1500 HD View In a New Tab
N Current Near Side View Standard Geocentric Earth View Sans Librations Geocentric Phase: 90°	N Current Far Side View Behind the Moon Looking Back Earth is Directly Behind Moon Relative Phase: 270°
N Current West Side View Centered Over Western Hemisphere Earth is Directly to the Right Relative Phase: 0°	N Current East Side View Centered Over Eastern Hemisphere Earth is Directly to the Left Relative Phase: 180°

LUNAR HEMISPHERIC PHASE EXPLORERS - HD EDITION FOR LARGE MONITORS DEVELOPED USING AN ULTRA-WIDE (2560x1080) HD MONITOR Author : Jay Tanner Revised : 2017-2022 Language : PHP v5.6.11 - v7.4.9 This program displays shaded lunar phase simulations of the four lunar hemispheres based on the NASA/JPL DE405 ephemeris model and lunar surface map composed from Clementine imaging and a digital elevation model (DEM) derived from the Lunar Orbiter Laser Altimeter (LOLA) altimetry data. On initial startup, the current phases are computed using the NASA/JPL DE405 ephemeris model spanning the 600-year period from 1600 to 2200, referred to the true equinox and ecliptic of the date. Refreshing the page updates the geocentric phases and ephemeris statistics for the current date and UTC. Although the images appear like photographs, they are computer-generated simulations based on NASA data and the phase shading computed from actual solar and lunar positions at the moment of computation, simulating reality very closely. There are 4 sets of lunar surface maps centered on the front side, far side, eastern and western hemispheres which can be viewed at any relative phase from 0 to 360 degrees. The images are 1500x1500 PNG images on transparent backgrounds covering the entire lunar surface. In terms of 3D perspective, all the hemispheric phase images are as viewed from the same mean geocentric distance of 238857 mi (384403 km) through a virtual telescope. Imagine the moon at the center of a circle with the sun moving around it from 0 to 360 degrees in a clockwise direction. The position of the sun on this phase circle is the simple lunar phase angle. The new moon is at zero degrees with the sun behind the moon, progressing clockwise from there and cycling through all the lunar phases from 0 to 360 degrees. Given the geocentric ecliptical longitudes of the sun and moon at the same moment, the simple lunar phase angle at the same moment can be computed to sufficient visual precision from the simple algorithm given below. A SIMPLE LUNAR PHASE ANGLE ALGORITHM -------------------------------------------------------- Let: Ls = Geocentric Ecliptical Longitude Of Sun (0 to 360°) Lm = Geocentric Ecliptical Longitude Of Moon (0 to 360°) PA = Geocentric Lunar Phase Angle (0 to 360°) Then: a = 360 − Lm + Ls if (a > 360) {a = a − 360} PA = 360 − a or: a = 360 − Lm + Ls PA = 360 − a −= (a > 360)? 360:0 -------------------------------------------------------- RELATIVE PHASE ANGLES (NORTH IS UPWARD) -------------------------------------------------------- Relative Phase PA Direction of Illumination ------------------ ------- ------------------------- New Phase 0° / 360° From behind the moon First Quarter 90° Directly from the right Full Phase 180° From behind the eye Last Quarter 270° Directly from the left ---------------------------------------------------------
Program and Graphics by Jay Tanner Revised: Thursday, January 01, 1970 at 12:00:00 AM UTC