Saturn over Mercury, Nov. 24, 2017
Bring binoculars to help scan for Saturn and Mercury very low in bright twilight. They're 4° apart this evening.
Mercury and Saturn in the sunset, Dec. 1, 2017
By a week later, on Friday December 1st, Mercury and Saturn are just 3° apart in the sunset glow.
Mars, Spica, and Jupiter in early dawn, late November 2017
Meanwhile in early dawn, orange Mars and blue-white Spica shine high to the upper right of Jupiter.
Mars, Spica, Jupiter, Venus in the dawn of Dec. 2, 2017
Mars and Spica leveling out in the dawn. Can you get a last glimpse of Venus just above the pre-sunrise horizon?

Friday, November 24

• Two challenge planets! No more than 20 or 30 minutes after sunset, scan with binoculars low in the southwest for Saturn over Mercury as shown at right. Today they're 4° apart. In the coming days Saturn will move down a little closer to Mercury, passing to its upper right.

• Whenever Fomalhaut "souths" — crosses the meridian due south, which it does around 7 p.m. this week — the first stars of Orion are just about to rise above the eastern horizon. And, the Pointers of the Big Dipper stand upright due north, straight below Polaris.

Saturday, November 25

• The bowl of the Little Dipper is descending the northern sky in the evening at this time of year, left or lower left of Polaris. By about 11 p.m. it hangs straight down below Polaris.

Sunday, November 26

• First-quarter Moon (exact at 12:03 p.m.). The Moon shines straight above Fomalhaut as the stars come out at dusk. The Moon appears to move to the upper right of the lonely star as the sky turns and evening grows late.

Monday, November 27

• The Moon, below the Great Square of Pegasus, forms a big triangle with Fomalhaut to its lower right, and orange Beta Ceti less far to the Moon's lower left (for North America and Europe).

Tuesday, November 28

• After dark this evening, look below the waxing gibbous Moon for Beta Ceti and above it for the Great Square of Pegasus.

Wednesday, November 29

• The five brightest stars of Cassiopeia are usually called a W, but now Cas is turning over to become a wide M, riding very high in the north by late evening.

Thursday, November 30

• Bright Vega still shines well up in the west-northwest after dark. The brightest star above it is Deneb, the head of the big Northern Cross, which is formed by the brightest stars of Cygnus. At nightfall the shaft of the cross extends lower left from Deneb. By about 11 or midnight, the cross plants itself more or less upright on the northwest horizon.

Friday, December 1

• The bright waxing gibbous Moon shines in the east this evening. Look upper right of it for the two brightest stars of Aries, left of it for the little Pleiades cluster, and below the Pleiades for orange Aldebaran.

Saturday, December 2

• The nearly-full Moon shines in Taurus this evening, upper right of Aldebaran and below or lower right of the Pleiades.

Does the Moon look just a trace bigger than usual? You're right! Tomorrow's full Moon is a "supermoon," in fact the closest full Moon of the year.

• Now that the Pleiades and Aldebaran are up in due east, can Orion be far behind? Orion's entire iconic figure, formed by its brightest seven stars, takes about an hour and a quarter to cross the horizon below them. By 10 p.m. Orion is well up in fine pre-winter view, under the Moon.


Want to become a better astronomer? Learn your way around the constellations! They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy.

Pocket Sky Atlas, jumbo edition
The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and hundreds of telescopic galaxies, star clusters, and nebulae among them. Shown above is the Jumbo Edition for easier reading in the night. Larger view. Sample chart.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, is the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, or the bigger Night Sky Observer's Guide by Kepple and Sanner.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (meaning heavy and expensive). And as Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."

This Week's Planet Roundup

Mercury and Saturn (magnitudes –0.4 and +0.5, respectively) are very low in the sunset afterglow, as shown in the first panels above. Scan for them with binoculars in the southwest no more than 20 or 30 minutes after sunset.

Venus, Mars, and Jupiter (magnitudes –3.9, +1.7, and –1.7, respectively) rise before or during dawn in the east-southeast.

First up is Mars, the dimmest, accompanied by Spica.

Jupiter rises well to their lower left a little before dawn begins.

Venus is getting extremely low and tough to spot as dawn grows bright! Look for it to rise far lower left of Jupiter. Their separation widens from 13° on the morning of November 25th to 20° on December 2nd. Jupiter is getting higher; Venus is sinking away.

Uranus (magnitude 5.7, in Pisces) and Neptune (magnitude 7.9, in Aquarius) are well placed in the southeast and south in early evenings. Use our finder charts online or in the October Sky & Telescope, page 50.


All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Standard Time (EST) is Universal Time (UT, UTC, GMT, or Z time) minus 5 hours.


"The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking, it's that credulous and confused thinking can be much more lethal in ways it was never before."
— Carl Sagan, 1996


"Objective reality exists. Facts are often determinable. Vaccines save lives. Carbon dioxide warms the globe. Bacteria evolve to thwart antibiotics, because evolution. Science and reason are not fake news, not a liberal political conspiracy. Civilization's survival depends on our ability, and willingness, to use them."
— Alan MacRobert, your Sky at a Glance editor


"Facts are stubborn things."
— John Adams, 1770



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