Listen to the story
For those of you who like to listen to your stories, click below to hear actor Susan Trishel Monsøn reading Chris Vaughan’s summary of the planets for September.
For Northern Hemisphere observers, November will offer an excellent opportunity to view Mercury in the eastern pre-dawn sky. During the first few days of the month, the speedy planet will still be climbing out of the morning twilight after inferior conjunction. But after that, Mercury’s position north of the steep morning ecliptic will allow skywatchers to see the planet shining in a dark sky. On November 10, Mercury will reach a maximum angle of 19 degrees from the Sun and peak visibility, especially between about 5:45 and 6:30 a.m. in your local time zone. Then the planet will descend sunward for the balance of the month, becoming harder to see in the closing week. Mercury’s visual magnitude will increase throughout November. Since the planet is heading toward superior conjunction in December, telescope views during November will reveal a rapidly waxing gibbous phase that reaches 95 per cent illuminated at month-end — and the planet’s apparent disk size will diminish from nine to five arc-seconds as it moves farther from Earth. On November 13, the pretty, crescent Moon will sit above Mercury and below the brighter planet Venus, with bright Spica sitting to the Moon’s right, making a lovely photo opportunity when composed with some interesting scenery.
During November, Venus will rise a few hours before dawn and shine at an extremely bright magnitude -3.9 in the eastern sky until sunrise. Meanwhile the planet will be slowly descending sunward, beginning the month in western Virgo, just 19 arc-minutes northeast of Eta Virginis, then passing close to Porrima on November 5, and four degrees north of Spica on November 16-17, and then crossing into Libra on November 28. Viewed in a telescope during November, the planet will exhibit an 85-per-cent-illuminated, waxing gibbous phase and a mean apparent disk diameter of 12 arc-seconds. On November 12, the pretty, crescent Moon will sit a palm’s width above Venus. The following morning, the Moon will descend to sit between Venus and much dimmer Mercury, with bright Spica positioned off to the Moon’s right — making a lovely photo opportunity when composed with some interesting scenery.
During November, Mars will be conveniently positioned for observing from dusk until the wee hours, culminating at a healthy 51 degrees elevation above the southern horizon by late evening. As Earth leaves Mars behind following October’s close opposition, the Red Planet will fade by a full magnitude from -2.11 to -1.13 during November, and telescope views will show Mars’ apparent disk diameter shrinking from 19.9 to 14.6 arc-seconds. On November 15, the Red Planet will complete a retrograde loop through Pisces that began in early September, and resume regular easterly motion, departing Pisces in early January. On November 25, the waxing gibbous Moon will sit five degrees to the southwest Mars.
During early November, Jupiter will shine in the lower part of the southwestern sky after dusk, allowing for decent telescope viewing for about an hour before it sinks into the west. By month-end that window will be much shorter. Jupiter will be moving eastward through the stars of northeastern Sagittarius in November. Its faster orbital speed will reduce its angular separation from slower-moving Saturn, from five to two degrees. The two planets will meet on December 21. During November, Jupiter will decrease slightly in brightness from magnitude -2.16 to -2.03, and its apparent disk diameter will shrink from 36.8 to 34.4 arc-seconds. The Great Red Spot will be visible every second or third night, and moon shadow transits will be visible on November 1, 8, 14, and 16 in the Americas. The young, crescent Moon will pass below Jupiter and Saturn on November 18-19, a grouping that will make a beautiful wide field image.
Like nearby Jupiter to its west, yellow-tinted Saturn will shine in the lower part of the southwestern sky after dusk during November, allowing for decent telescope viewing for about an hour before it sinks into the west. By month-end, that window will be much shorter. Meanwhile, Jupiter’s faster orbital speed will reduce their angular separation from five to two degrees. During November, Saturn will diminish slightly in apparent size, and fade from magnitude 0.59 to 0.64. Saturn’s rings, and many of its moons, are visible in backyard telescopes. The young, crescent Moon will pass below Jupiter and Saturn on November 18-19, a grouping that will make a nice photograph when composed with some attractive foreground scenery.
During November, blue-green Uranus will be visible all night long while it travels slowly westward in southwestern Aries – about 11 degrees south of Aries’ brightest star Hamal, or five degrees north of the stars that form the top of Cetus’ head. Fresh from opposition on October 31, Uranus will still appear slightly larger and brighter in telescopes during early November, especially in late evening, when it’s 60 degrees high in the southern sky. The bright Moon will pass a few degrees south of Uranus on November 27, showing you where Uranus is, but use the moonless middle weeks of the month to try seeing the magnitude 5.7 planet with unaided eyes or binoculars.
Neptune will be well-positioned for observing in the evening sky during November. The best time to view the distant planet will be when it culminates 40 degrees above the southern horizon, at about 9 p.m. local time on November 1 and two hours earlier on November 30. On November 28, Neptune will complete a retrograde loop that has been carrying it westward through the stars of Aquarius since late June, then it will resume regular eastward motion. From dark sky locations, the magnitude 7.9 planet can be observed in good binoculars and backyard telescopes. Look 44 arc-minutes to the northeast of the medium-bright star Phi Aquarii. Both the planet and that star will appear together in the field of view of a telescope at low magnification (red circle).
Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.