{"version":1,"generatedAt":"2026-10-28T10:38:56.207Z","kind":"greatest-elongation","name":"Mercury at greatest western elongation, 7 Dec 2025","at":"2025-12-07T21:10:00.000Z","planets":[{"name":"Mercury","magnitude":-0.41}],"place":{"ra":15.553,"dec":-16.77,"frame":"J2000","raUnit":"hours","decUnit":"degrees"},"degreesFromSun":20.7,"sky":"morning","elongationDeg":20.7,"litFraction":0.62,"visibility":{"longitude":0,"timeZone":"UTC","twilightSunAltitude":-6,"bands":[{"latitude":60,"verdict":"low","summary":"Low: 7° up in the SE at 07:50; a clear, flat horizon needed","best":{"at":"2025-12-08T07:50:00.000Z","altitude":6.7,"azimuth":142,"sunAltitude":-6.2}},{"latitude":45,"verdict":"clear","summary":"11° up in the SE at 06:50","best":{"at":"2025-12-08T06:50:00.000Z","altitude":10.9,"azimuth":128,"sunAltitude":-6.3}},{"latitude":30,"verdict":"clear","summary":"12° up in the ESE at 06:10","best":{"at":"2025-12-08T06:10:00.000Z","altitude":12.3,"azimuth":118,"sunAltitude":-7.5}},{"latitude":15,"verdict":"clear","summary":"15° up in the ESE at 05:50","best":{"at":"2025-12-08T05:50:00.000Z","altitude":14.6,"azimuth":112,"sunAltitude":-6.2}},{"latitude":0,"verdict":"clear","summary":"13° up in the ESE at 05:20","best":{"at":"2025-12-08T05:20:00.000Z","altitude":12.6,"azimuth":107,"sunAltitude":-7.3}},{"latitude":-15,"verdict":"low","summary":"Low: 10° up in the ESE at 04:50; a clear, flat horizon needed","best":{"at":"2025-12-08T04:50:00.000Z","altitude":9.7,"azimuth":105,"sunAltitude":-7.9}},{"latitude":-30,"verdict":"low","summary":"Low: 7° up in the ESE at 04:20; a clear, flat horizon needed","best":{"at":"2025-12-08T04:20:00.000Z","altitude":6.9,"azimuth":106,"sunAltitude":-6.8}},{"latitude":-45,"verdict":"lost","summary":"Lost in the horizon's haze: 2° up at best once it is dark","best":{"at":"2025-12-08T03:30:00.000Z","altitude":2.2,"azimuth":112,"sunAltitude":-6}}]},"links":{"page":"https://www.whatthestar.com/planets/mercury-greatest-elongation-2025-12-07","map":"https://www.whatthestar.com/explore?ra=15.553&dec=-16.77&fov=40&t=2025-12-07T21%3A10%3A00.000Z"},"sources":[{"name":"P. Bretagnon and G. Francou, VSOP87, the planetary theory the map draws, held to JPL’s DE441 within about an arcsecond over 1900–2100","url":"https://www.whatthestar.com/credits#method-planets"},{"name":"U.S. Naval Observatory and Sea and Sky’s Astronomy Calendar of Celestial Events: the dates and angles the tests hold these to","url":"https://aa.usno.navy.mil/data/"},{"name":"A. Mallama and J. Hilton (2018) and the Astronomical Almanac’s phase-angle series: the planets’ magnitudes","url":"https://www.whatthestar.com/credits#method-planets"},{"name":"J. Meeus, Astronomical Algorithms, ch. 25: the Sun, for the twilight each latitude is judged in","url":"https://www.whatthestar.com/credits#method-sun"}]}