Mercury now shines at magnitude 0 in Gemini and is visible in the western sky for about an hour and a half after sunset. The planet lines up with the heads of the Twins this evening: Looking west around 9:30 P.M. local daylight time should show you a line of three bright points about 5° high, slanted slightly toward the ground. The leftmost point, brightest and closest to the horizon, is Mercury. In the middle is the next-brightest, Pollux, which shines at magnitude 1.2 with a slightly golden glow. At the right and highest up is Castor, the dimmest at magnitude 1.6.
Through a telescope, Mercury’s disk spans 7” — a larger apparent size than Mars! Although physically Mercury is much smaller than Mars, it’s currently closer to Earth than the Red Planet, giving it that size bump. The disk of Mercury is also just over half lit, appearing as a 57-percent-lit gibbous. It is currently waning each night and will appear exactly 50 percent illuminated on the 28th.
Sunrise: 5:33 A.M.
Sunset: 8:33 P.M.
Moonrise: 4:13 A.M.
Moonset: 10:27 P.M.
Moon Phase: Waning crescent (1%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.
