Jeffers Foundation



September, 2017

Planet Mercury: Mid-morning twilight
Planet Mercury: Mid-morning twilight
This month Mercury makes its best appearance of the year in the pre-dawn sky. Mercury isn't the only bright object visible before sunrise, however. During the first two weeks of the month, Leo's brightest star, Regulus, accompanies Mercury, appearing just two-thirds of a degree north of the planet on September 10. Mars also occupies the same sector of the sky, keeping pace with Mercury through the first day of autumn. Look for Mercury and the Red Planet separated by a quarter of a degree on September 16!

Morning Sky

Mercury, Venus, and Mars make a very impressive sight as they bunch up in the pre-dawn sky this month. Look for Mercury's September elongation between five and eight degrees above the eastern horizon 45 minutes before sunrise. On the morning of September 16, Mercury and Mars will appear side-by-side, with just one fourth of a degree between them! Leo's brightest star, Regulus, appears above the Mercury-Mars pair, with Venus still higher. The Moon passes Venus and Regulus on September 17, then Mars and Mercury the very next day. Don't miss this incredible display!

Evening Sky

Jupiter becomes increasingly difficult to locate as the month advances, sinking into the Sun's glare. By month's end, Saturn is the only planet visible after sunset. Look for the famous ringed planet 20 degrees above the south-southwestern horizon an hour after sunset. The Moon appears beside Saturn on September 26.

Sun Declination


6th, Full Moon - 2:03 am

13th, Last Quarter Moon - 1:25 am

13th, Moon perigee; 229,819 miles - 11:11 am

20th, New Moon Wild Rice (Ojibwe) - 12:30 am

22nd, Autumnal equinox; fall begins N Hemisphere - 3:02 pm

25th, Antares 8.7 degrees south of Moon - 7:44 pm

26th, Saturn 2.65 degrees south of Moon - 7:50 pm

27th, First Quarter Moon - 9:54 pm

27th, Moon apogee; 251,251 miles - 1:47 am

Like Us On Facebook Visit Our Vimeo Channel

/* connect */