Setting our clocks back to standard time on Sunday, Nov. 1, means that the clock times of sunrise, sunset and our deep twilight sky-viewing times will all shift an hour earlier. I hope you will not be deterred from enjoying the truly spectacular predawn sights in the coming weeks.
The two brightest planets, Venus and Jupiter, appear 61° apart on Nov. 2, closing to 57° apart during Nov. 12-20, and reopening to 61° by Nov. 30. In coming months, they’ll spread apart: By early March 2027, Venus and Jupiter will appear just a few degrees above opposite horizons just before morning twilight, so enjoy them now!
In November, each has first-magnitude companions nearby. Observe during the deep twilight about one hour before sunrise, and you’ll find Jupiter high in the east-southeast to southeast early in the month, and high in the south-southwest by month’s end. Mars and Jupiter are both moving eastward toward Regulus, but Mars is closing in more quickly, by 0.5° daily at the start of November, while Jupiter creeps only 2.4° east during the entire month. The gathering is becoming more compact!
Watch for striking changes in the arrangement of Mars-Jupiter-Regulus. On Nov. 15 and 16, Mars will pass 1.2° north of Jupiter, while Regulus appears within 4.5° east of the planetary duo on Nov. 16. Compare to the 4.5° separation of Gemini’s “Twin” stars, Pollux and Castor, high in the west. For 15 consecutive mornings, the planet pair and Regulus form a trio, fitting within a 5° field of view, a beautiful sight for binoculars of less than 10-power. Their most compact arrangement, 3.7° wide, occurs on the morning of Nov. 25, one day before Thanksgiving, when Mars will pass just 1.7° north of Regulus.
The pairing of Regulus and Mars on Thanksgiving morning is the first of a triple conjunction between the two objects. Their second pairing, 4° apart on Feb. 20, 2027, will be visible all night, as the Earth passes between the sun and the two objects on the two previous nights. (Earth’s faster orbital motion causes Mars to appear to move westward or backward—retrograde—against the stars.) The third and closest Mars-Regulus pairing, 1.2° apart, will be seen in the evening sky on May 14. Mars’ most recent triple conjunction with Regulus occurred in 1979-’80, and the next will happen in 2073-’74.
The pairings Jupiter-Mars and Jupiter-Regulus are single this time, on the morning of Nov. 16 (1.2°) and in the evening of July 26, 2027 (0.4°), respectively.
The other center of activity in the morning sky is Venus, the brightest planet. On Nov. 1, Venus, at magnitude -4.3, rises in the east-southeast in twilight, just less than an hour before sunrise. Using binoculars that morning, try for the star Spica, marking the stalk of grain in the hand of Virgo, 3.2° to the upper left of Venus. Both Venus and Spica rise earlier and ascend noticeably higher from one morning to the next, Spica doing so as a result of the Earth’s orbital revolution around the sun, and Venus because it has just overtaken Earth on Oct. 24. As a result, Venus will appear to make a tight loop around Spica, passing 1.4° to 1.3° to right of Spica on Nov. 6 and 7. Two days later, Venus passes closest to the star, within 1.2° to its upper right, on Nov. 9. Next, Venus passes 1.4° above the star on Nov. 13-14. By Nov. 25 —the morning of the most compact trio of Jupiter-Mars-Regulus—Venus, at greatest brilliancy, shines at magnitude-4.9 while 2.9° to the left of Spica. At month’s end, Venus appears 5° to lower left of Spica.
Mercury passes nearly between Earth and the sun on Nov. 4 and quickly climbs into the morning sky. Mercury lingers 13° to the lower left of Venus Nov. 10-16, while brightening through magnitude +1 on Nov. 13 and magnitude 0 on Nov. 16. The innermost planet reaches greatest elongation, nearly 20° from the sun and 15° to the lower left of Venus, on Nov. 20, and shines at a steady magnitude -0.6 for rest of November. On Nov. 30, Mercury is still easy to spot, 24° to the lower left of Venus.
The waning moon in morning sky: On Nov. 2, the moon, a fat crescent just past last-quarter phase, appears very close to Mars, with Jupiter and Regulus nearby. The lineup of these four bodies on Nov. 1 and Nov. 3 is very attractive. On Nov. 7, the 3 percent old crescent—with earthshine on its upper side, very low in the east-southeast—is joined by Venus and Spica to its upper left, all within a 3 1/2° field! A wonderful photo-op!
The moon begins another pass through the morning sky in late November. Binoculars show the Pleiades cluster very near the full moon on Nov. 24. The next morning, the moon is widely north of Aldebaran and the Hyades. On Nov. 27, the moon forms an isosceles triangle with the Twins. Finally, on Nov. 30, the moon, approaching last quarter, appears in a compact gathering with Jupiter, Mars and Regulus.
Morning telescopic views: Close to Earth and mostly backlighted by the sun, Venus is showing its most striking phases, starting this month as a large, thin crescent, 3 percent illuminated and 59” (arcseconds) across, nearly 1/60 of a degree. A magnification of about 30-power now makes Venus appear about as large as the moon with the unaided eye. At month’s end, Venus is 27 percent lit and 39” across, still slightly larger than Jupiter. All month, if you observe Venus close to the time of sunrise, or even in the daytime, even binoculars will reveal the planet’s crescent phase. Jupiter, through a telescope and even binoculars, will show its disk, 36” to 39”, with up to four of its moons discovered by Galileo. Mars shows a very tiny disk, 7” across at midmonth, slated to double to nearly 14” in late February, when Mars will be closest to Earth and brightest. For now, use high telescopic magnification when the air is steady, and note how bright the northern edge of Mars appears. You’ll be seeing Mars’ north polar cap in the early spring of the planet’s northern hemisphere!
Use your binoculars to observe the moon when visible, and other morning wonders, including the Great Nebula in the Sword of Orion, and the Hyades and Pleiades star clusters in Taurus.
Evenings: Saturn, at magnitude +0.5 to +0.7, is the only bright planet visible at dusk. Look in the east-southeast to southeast, nearly in line with the east side of the Great Square of Pegasus. A telescope shows its rings tipped about 6° from edge-on. Follow the moon from its thin crescent phase low in the southwest on Nov. 10 or 11, to a fat crescent approaching first quarter on Nov. 16, and on to just past Saturn on Nov. 20. Watch the nearly full moon close in on the Pleiades on the night of Nov. 23.
These celestial events, and others, are included on the Abrams Planetarium Sky Calendar, available by subscription for $12 per year. Learn more at abramsplanetarium.natsci.msu.edu/sky-calendar.
Robert Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys promoting sky watching to folks of all ages. Robert Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.
