Waxing moon
The waxing Moon just before first-quarter phase, as it appears in an amateur telescope magnified about 40 times. The Moon changes phase from night to night, revealing new features every step of the way. It's near this phase tonight (December 25, 2017) and grows wider through the coming week &dmash; as the terminator, the sunrise line, moves left, unveiling more of the lunar surface. The Moon will next be at the phase above on the evening of January 23, 2018.

Maybe you just got a shiny new telescope to call your own. Congratulations — you could be on your way to discovering many amazing, far, deep things in the night sky. Although most of them are so far and faint that just locating and detecting them is the challenge! Whether your new scope is a long, sleek tube or a compact marvel of computerized wizardry, surely you're itching to try it out.

"Here are three crucial tips for getting started," advises Alan MacRobert, a senior editor at Sky & Telescope magazine.

"First, get your scope all set up indoors, read the instructions, and get to know how it works — how it moves, how to change eyepieces, and so on — in warmth and comfort. So you don't have to figure out unfamiliar knobs, settings, and adjustments outside in the cold dark.

"Second, take it outside in the daytime and get familiar with how it works on distant scenes — treetops, buildings — to get a good feel for what it actually does. For instance, you'll find that a telescope's lowest magnification (the longest-focal-length eyepiece) gives the brightest, sharpest, and widest views, with the least amount of the wiggles. The lowest power also makes it easiest to find what you're trying to aim at, with that wide field of view. So you'll always want to start off with the lowest power. Switch to a higher power only after you've found your target, got it centered, and had a good first look.

"Also, if the telescope has a little finderscope on the side, daytime is the easiest time to 'align' the finderscope. Point the main telescope at a distant treetop or landmark, center it in the view, and then look through the finderscope. Use the finderscope's adjustment screws to get the crosshairs centered on the same treetop. Then recheck that it's still in the center of the main scope's view.

"Third," he adds, "be patient. Spend time with each sky object you're able to find, and really get to know it." Too many first-time telescope users expect Hubble-like brightness and color in the eyepiece — when in fact most astronomical objects are very dim to the human eye. And, our night vision sees almost everything as shades of gray. Much of what the universe has to offer is subtle, and, once again, extremely far away! But the longer and more carefully you examine something, the more of it you'll gradually discover coming out.

On the other hand, the Moon and the naked-eye planets are bright and easy to find! They make excellent first targets for new telescopic observers. Sky & Telescope's This Week's Sky at a Glance has suggestions for both telescopic and naked-eye viewing of the brightest stars and planets.

Here are some suggestions for starting off:

New-Telescope Delight: The Moon

The Moon is one celestial object that never fails to impress in even the most humble scope. It’s our nearest neighbor in space — big, bright, starkly bleak, and just a quarter million miles away. An amateur telescope and a good Moon map can keep you busy forever.

Full Moon
See if you can identify these noteworthy features around the time of full Moon. Some of the most prominent craters display bright rays: splashes of impact debris.
Bob King

The Moon is well-placed in the evening sky this week (December 25–31, 2017) as it waxes from first-quarter to gibbous toward full. It's full on the night of January 1st. But full Moon is actually the worst time for telescopic Moon viewing, because its full, directly sunlit face lacks the shadows that cast mountains and craters into sharp relief. The waxing and waning phases are better, especially for features along the terminator — the lunar sunrise or sunset line. Here you'll see lunar features standing out at their best. The terminator moves quite a bit from night to night, revealing new landscapes when the Moon is waxing and covering them when waning.

Planets: Jupiter and Mars

Most of the solar system's bright planets are out of good sight just now, hidden in the glare of the Sun as seen from Earth's viewpoint. The exceptions are Jupiter and Mars. For them, plan an early-morning darkness adventure.

Go out with your scope shortly before the first light of dawn, which begins about an hour and a half before your local sunrise time. Look southeast, moderately high. If you have a clear sky view in that direction you can't miss Jupiter — it's the brightest point up there! "Jupiter is the king of the planets and the most interesting one for a small telescope," says MacRobert. "It's big, it's bright, it has cloud belts, and it has four moons that do interesting things."

Even at 50× or 100×, you should be able to make out two pale, dusky-tan bands girding Jupiter's midsection: the North and South Equatorial Belts. These, and the brighter Equatorial Zone between them, are cloud features akin to jet streams high in the Jovian atmosphere. (Jupiter is a gas giant with no solid surface.)

Larger telescopes — with a main mirror or lens at least 6 inches across — may bring a few more belts and zones into view, along with an assortment of spots and streaks. However, the best time to view anything with a telescope is when it's very high in the sky, where you're looking through the thinnest amount of Earth's fuzzy, distorting atmosphere. Jupiter's won't be viewable at its highest for a couple months yet — but astronomy is about making the most of what you've got. Jupiter's famous Great Red Spot, a huge cyclonic storm larger than Earth, may be detectable if you're looking at a time when it's facing Earth. Jupiter completes a rotation in just under 10 hours — causing its globe to bulge out visibly at the equator — and the Red Spot is easiest to see around when it crosses the midline of Jupiter's Earthward face. You can find the times when this happens using our online app.

With your first look at Jupiter, you'll immediately notice the array of bright little moons on either side of it, more or less aligned with the belts. These are the four "Galilean satellites," named for Galileo, who discovered them from Italy in 1609-10. "From night to night you'll see their movement as they shuttle around Jupiter," notes MacRobert. "Sometimes not all four are visible: occasionally one of them ducks behind Jupiter or is hidden in its shadow." Their own tiny black shadows sometimes cross Jupiter's face. How can you tell which moon is which? We've got an app for that too.

For more about what to look for on and around Jupiter, check out our Jupiter observing guide.

Mars glows to Jupiter's upper right this week, not nearly as bright. Its yellow-orange color helps give it away. Mars is a small planet and it's currently on the far side of its orbit from Earth, so even a rather large telescope currently shows it basically a tiny, fuzzy blob. But 2018 is going to be a big year for Mars. Next July and August, Earth will pass closer to Mars than have in 15 years, and small scopes should reveal surface markings and perhaps the white South Polar Cap.

More New-Telescope Sights

There's more to the night sky than the nearby Moon and planets, of course. Winter evenings often bring crisp, transparent skies with a grand canopy of stars. But with so many inviting targets overhead, where should you point first?

How to find the Orion Nebula
This chart shows where to find the Orion Nebula, in Orion's Sword below the trio of stars forming Orion's Belt. Only the brightest stars (the largest dots) on this chart are readily visible to the unaided eye.

The familiar constellation Orion climbs in the southeast these evenings. In its middle, look for the three-star line of Orion's Belt. It's currently nearly vertical in early evening, and it's diagonal (like on the chart at right) late at night.

Just a few degrees south of the Belt (a few finger-widths at arm's length) runs a smaller, dimmer line of stars: Orion's Sword. Within it lies the Orion Nebula, a luminous cloud of gas and dust where stars are forming by the hundreds. It shows pink in most photographs, but dim gray with a hint of green to the human eye. The nebula is plain in any telescope once you get pointed at it, and so is the tight quartet of stars near its center, called the Trapezium. Astronomers sometimes refer to this nebula as Messier 42 (M42), and you'll see it labeled that way on star charts. Located about 1,400 light-years away, it's the closest massive star-forming nebula to Earth. Dim objects like nebulae are best seen when the sky is really dark and moonless, but again, make the best of the situation you've got.

You can use Orion's Belt as a pointer to other things. Extend the line far upward, past the relatively bright star Aldebaran (the orange-red eye of Taurus, the Bull) and you'll reach a little cluster of stars called the Pleiades. It's about the size of your fingertip held at arm's length.

Through binoculars or a telescope at its lowest magnification, the Pleiades cluster shows dozens of stars. Astronomers have determined that the cluster has about 500 in all. Like other star clusters, the Pleiades are held together by their mutual gravity. Collectively called an open cluster for their relatively uncrowded arrangement, the Pleiades move together through space as a swarm. They're about 435 light-years away.

Researchers have determined that the Pleiades stars began to shine only about 70 to 100 million years ago. This makes the stars mere toddlers compared to our Sun and solar system, age 4.6 billion years. M45’s youthful suns are astonishingly energetic. Alcyone (al-SIGH-oh-nee), the brightest, is at least 350 times as luminous as our Sun. Like the other bright Pleiads it gleams with an intense blue-white light — a sign that it’s unusually hot and massive.

Next Steps in Astronomy

To find much else in the night sky, you'll need to start learning the naked-eye constellations overhead. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope — the same way you need to know the continents and countries on a globe of Earth before you can pinpoint, say, Madras, India on the globe. 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 magazine, the essential guide to astronomy (ahem).

You'll also want a good, detailed star atlas (set of maps), such as the widely used Pocket Sky Atlas; a good deep-sky guidebook; and some practice in how to use the maps to pinpoint the aim of your telescope onto a faint something. (There are a few key tricks to this — see Using a Map at the Telescope.)

For more tips on skywatching and how to get the most out of your telescope, see our Observing section and Getting Started section.

Whatever else, stick with it! Nobody is born knowing this stuff. Everyone has to work their way into the hobby at their own comfortable pace, finding things to know and do and understand and not worrying about everything they don't yet. Living in the universe is kind of like that.


Image of Graham-Wolf


December 26, 2017 at 9:45 pm

Great article, Alan.

These are things to see even with your OLD telescope, ANY telescope.
Even the thin crescent Moon looked awesome in the evening sky at low power, Xmas Eve.
Was using a simple 20X 80mm Polarex Terrestrial refractor at the time.

Even stole a quick glance at NGC 3372 and M42, with my 10x50 Binocs... you certainly don't need Palomar sized optics... BUT, you certainly need to get off the couch, though.

Just get out there, and observe!

Regards from Graham W. Wolf:-
46 South, Dunedin, New Zealand

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