FRIDAY, NOVEMBER 25
■ Now that the Pleiades and Aldebaran shine in the east after dark, can Orion be far behind? Orion's entire iconic figure, formed by its brightest seven stars, takes about an hour and a quarter to clear the eastern horizon. By roughly 8 p.m. it's just about made it, as shown below. By 10 it's up in fine, pre-winter view.
■ Jupiter blazes bright white in the south in early evening. Using a telescope, watch for Jupiter's moon Io to slowly reappear from behind Jupiter's eastern limb around 7:11 p.m. EST, soon after dark in the Eastern time zone. Then Europa does the same around 10:41 p.m. EST, better timing for the rest of North America.
Watch for each to gradually appear as a tiny bump on Jupiter's shimmering limb, then bud off and separate into open space.
Meanwhile, Jupiter's Great Red Spot should cross the planet's central meridian around 7:22 p.m. EST. Fifty minutes later it's already halfway to the preceding (celestial west) limb. Jupiter rotates fast. A light blue or green filter may help a little in showing the Red Spot and contrast in Jupiter's tan belts.
SATURDAY, NOVEMBER 26
■ The bowl of the Little Dipper swings down in the evening at this time of year, left or lower left of Polaris due north. The rest of the Little Dipper is dim. By about 11 p.m. this week it hangs straight down from Polaris.
■ The Moon will soon start brightening the evening sky. So take advantage of the dark now. The Andromeda Galaxy (M31) and the Perseus Double Cluster are two of the most famous deep-sky objects. They're both cataloged as 4th magnitude, and in a fairly good sky you can detect each with the unaided eye. Binoculars make them easier. They're located only 22° apart, very high toward the east early these evenings — to the right of Cassiopeia and closer below Cassiopeia, respectively.
But they look rather different, the more so the darker your sky. See for yourself. You can find them by carefully using the all-sky constellation map in the center of the November or December Sky & Telescope.
SUNDAY, NOVEMBER 27.
■ As twilight fades, look low in the southwest for the crescent Moon. It forms a giant, nearly equilateral triangle with Altair high above it and a bit right, and Saturn high to the Moon's upper left. The triangle is three or four fists at arm's length on a side.
MONDAY, NOVEMBER 28
■ During and after dusk, Saturn glows above the thickening crescent Moon in the south-southwest.
■ Once Orion climbs up in the east-southeast after dinnertime, look for Gemini also gaining altitude to Orion's left (for mid-northern latitudes). The head stars of the Gemini twins, Castor and Pollux, are at the left end of the Gemini constellation — one over the other, with Castor on top. The stick-figure Twins are lying on their side.
TUESDAY, NOVEMBER 29
■ Now Saturn glows to the right or lower right of the Moon during and after dusk.
■ As the stars come out, the Cassiopeia W stands on end (its fainter end) high in the northeast. Watch Cas turn around to become a flattened M, even higher in the north, by late evening.
WEDNESDAY, NOVEMBER 30
■ Mars is closest to Earth tonight, exactly so at 9 p.m. EST (2h UT December 1st), its closest until 2033. But for all practical purposes it's just as close for at least a week before and after. Rounded to the nearest tenth of an arcsecond (!) Mars stays 17.2 arcseconds in diameter from November 28th through December 4th. You won't see any difference whatever for at least a week before and after those dates.
So if you're going to announce a Mars's Closest Approach observing night for the public, set the date by weather and convenience, not by invisible microscopic exactitude. If anyone objects "You got the wrong date! On TV they said..." you can take the opportunity to educate about significant precision in matters of observation and measurement. I don't think I've ever heard a TV announcer talking about astronomy who seemed to grasp this.
■ First-quarter Moon (exact at 9:37 a.m. EST). The Moon is in the dim water bucket that stick-figure Aquarius spills as he runs. Upper left of the Moon shines bright Jupiter. They tilt at an increasing angle as the evening progresses and the sky turns.
THURSDAY, DECEMBER 1
■ Even as Mars has its crowning nights, brighter Jupiter tries to steal the show this evening by pairing up with the Moon. In late twilight and early evening, they're high and the line they make doesn't tilt too much. By 11 p.m. they're lower in the west-southwest and have twisted to be oriented almost vertically, as shown below.
■ Also: Above the Moon and Jupiter in early evening, the Great Square of Pegasus floats at its highest overhead. It's made of 2nd- and 3rd-magnitude stars. Your fist at arm's length fits inside it.
The western (right) side of the Great Square points far down almost to 1st-magnitude Fomalhaut in the south. Its eastern side points down less directly toward 2nd-magnitude Beta Ceti (Diphda), less far below. Don't let the two bright intruders along the way distract you.
FRIDAY, DECEMBER 2
■ By about 7:30 p.m. Orion is clearing the eastern horizon, depending on how far east or west you live in your time zone.
Orion's tilt while rising depends on your latitude. If you live north of 33° N (Los Angeles, Atlanta, the Nile delta, Shanghai), Betelgeuse will be higher than Rigel. If you're south of 33°, Rigel will be the higher one just after they rise; Orion comes up foot first.
As the night goes on, however, Betelgeuse always gain the upper position — as seen from anywhere in the Northern Hemisphere.
■ A small telescope will show much more about lunar geology than craters, plains and mountains. As the terminator now unveils more of the waxing gibbous Moon, get out your lunar map to use with Chuck Wood's "Layer Upon Layer Upon Layer" article in his Exploring the Moon column and photos, December Sky & Telescope, page 52. "Follow the clues leading back to the formation of two large lunar basins." You may have seen these clues but not recognized what they are!
SATURDAY, DECEMBER 3
■ Vega still shines brightly well up in the west-northwest after dark. The brightest star above it is Deneb, the head of the big Northern Cross, formed by the brightest stars of Cygnus. At nightfall the shaft of the cross extends lower left from Deneb. By 10 or 11 p.m. it plants itself more or less upright on the northwest horizon.
This Week's Planet Roundup
Mercury and Venus hide deep in the glow of sunset.
Mars, magnitude –1.7, hangs low in the east-northeast as the stars begin to come out. It gains altitude until culminating nearly overhead around midnight or 1 a.m. There's no missing it; Mars outshines even Sirius (which rises around 9 p.m.). Mars's fiery yellow-orange color always helps give it away. In a telescope Mars is 17.2 arcseconds wide, the biggest we'll see it until 2033.
Mars is on its way to opposition the night of December 7-8 — when the full Moon will occult Mars for much of North America and Western Europe! Map and timetables. See the December Sky & Telescope, page 49, for more information and also a table of the near-miss times and separations for cities in the eastern U.S outside the occultation zone.
Mars-colored Aldebaran, only a tenth as bright at magnitude +0.9, sparkles about 11° to Mars's upper right. Twice as far lower left of the planet is Mars-colored Betelgeuse.
Jupiter blazes white high in the southeast in twilight at magnitude –2.6. It's highest in the south about an hour after dark now, in dim Pisces. It's down to 44 or 43 arcseconds wide.
Saturn, magnitude +0.8 in Capricornus, glows in the south-southwest as twilight fades. As night progresses, it moves lower toward the southwest and sets around 10 p.m.
Uranus, magnitude 5.7 in Aries, is well up in the east in good binocular or telescope view by mid-evening. It displays a tiny, very slightly blue-greenish gray disk 3.7 arcseconds wide. It a telescope at high power it's obviously non-stellar. See the Uranus finder charts in the November Sky & Telescope, page 49.
Neptune, magnitude 7.9 at the Aquarius-Pisces border, is high in the evening 6° west of Jupiter. It's just 2.3 arcseconds wide, again non-stellar in a telescope but requiring more effort than Uranus. It's slightly bluish gray, if you have enough aperture to show color at all in something this faint. See the Neptune finder charts in the September Sky & Telescope, page 49.
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 and graphics that also depend on longitude (mainly Moon positions) are for North America.
Eastern Standard Time (EST) is Universal Time minus 5 hours. Universal Time is also called UT, UTC, GMT or Z time.
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 magazine of astronomy.
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, are the even larger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to magnitude 9.75). And be sure to read How to Use a Star Chart with a Telescope. It applies just as much to charts on your phone or tablet as to charts on paper.
You'll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham's Celestial Handbook. An impressive more modern one is the big Night Sky Observer's Guide set (2+ volumes) 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."
Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty's monthly
podcast tour of the heavens above. It's free.
"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
"Facts are stubborn things."
— John Adams, 1770