Every year, New York’s Hayden Planetarium hosts a debate in memory of the renowned science and science-fiction writer Isaac Asimov. The topic of the most recent debate, held on March 15, 2010, was “Moon, Mars and Beyond: Where Next for the Manned Space Program.” The debaters — or more accurately, panelists — were all extraordinarily well qualified to discuss the subject:

Kenneth Ford, expert on artificial intelligence and human cognition, and chairman of the NASA Advisory Council.

Lester Lyles, retired Air Force General, formerly in charge of diverse military space programs.

Paul Spudis of the Lunar and Planetary Institute, one of the world’s leading lunar scientists and a major advocate for a sustained human presence on the Moon.

Steven Squyres of Cornell University, co-leader of and spokesman for the Mars Exploration Rover Project.

Robert Zubrin, aerospace engineer, popular writer, and leader of the movement to launch a quick and aggressive manned Mars program.

And last but by no means least, the moderator: Neil deGrasse Tyson, astrophysicist, space expert, television star, director of the Hayden Planetarium — and (like me) a graduate of the Bronx High School of Science.

The event proved to be wildly popular, despite very modest publicity. Hundreds of people were standing on line when I arrived, a half hour early, and hundreds more joined later. Every seat in the very large auditorium was taken, and a large overflow crowd watched the debate by simulcast. Many of the remarks — particularly those by Zubrin, but also many others — elicited prolonged cheers and applause.

Tyson opened the event, explaining that though billed as a debate, it would in fact be more like an informal discussion, a bunch of interested people sitting around a table at a bar. The reality was rather different, proceeding more like a television interview. After brief opening remarks by each participant, Tyson would ask each panelist a question, sum up the answer, and then ask a related question of the next panelist. In less competent hands, the format might have been stifling. But Tyson’s questions were so cogent and his summations so accurate that he elicited a very lively yet (on the whole) courteous interchange among the panelists.

Toward the end of the event, the format was broken by Buzz Aldrin, who had been invited to participate by telephone. Aldrin proceeded to lay out his program for manned spaceflight in intricate detail and at very great length. Tyson tried to cut Aldrin short several times, but it’s hard to dominate someone who isn’t physically present, and it’s equally hard to say no to the second man to walk on the Moon. After Aldrin had finished, the format was more open and direct, proceeding soon to questions from the audience — several of which were more statements or tirades than questions at all.

Tyson had intended the debate to focus on whether we should proceed directly to Mars (as advocated most strongly by Zubrin) or use the Moon as a trial and staging exercise, as proposed (though never funded) by the Bush administration. But in the interim between the planning and the event, the Obama administration had proposed yet another course, focusing neither on the Moon nor Mars but instead on the development of new technologies and the privatization of space. Zubrin reserved his greatest scorn for this new plan, pronouncing it to be a death sentence for human spaceflight, and stating that NASA had never accomplished anything useful except in pursuit of a lofty and specific goal, like the first human Moon landing. All the other panelists had more nuanced responses, ranging from very strong though mild-mannered support of NASA’s technology programs from Ford and Lyles to an agreement by Spudis and Squyres (and perhaps Tyson) that NASA needed to be more goal-oriented but not necessarily fixated on Mars as Zubrin is.

I can only touch on a few highlights of the discussion; it ranged over a very wide range of subjects. Spudis is perhaps the strongest advocate for the Moon as a destination in its own right, not just a steppingstone to Mars. Squyres brought up asteroids as a potential destination, suggesting that mining asteroids is the most promising commercial application of spaceflight beyond Earth orbit. Several people alluded to the possibility of landing on Mars’s moon Phobos, a proposal that’s taken very seriously by the human-spaceflight community, though it's never been noticed much by the wider public.

Almost everybody talked about the commercialization of space. Many people spoke, both pro and con, about space as a demonstration of national prestige and prowess. Intriguingly though perhaps not surprisingly, retired general Lyles was the strongest advocate of international cooperation, and the strongest opponent of using space as an instrument of national competition.

I was intrigued that nobody either on the panel or in the audience questioned the aggressive pursuit of human spaceflight. In my mind that’s very much an open question — which is not the same thing as saying that the answer to the question is necessarily no. But refusing to take such a fundamental question seriously, taking human spaceflight as axiomatic and not enquiring into its rationale, is a sign of weakness rather than strength.

But for better or worse, this was a panel and audience of true believers — and a very lively, fascinating, and invigorating bunch it was.

Binocular stargazing is one of my favorite activities. Telescopes may offer more spectacular views, but binocular astronomy has a peaceful, organic quality that's easy to lose when you're zoomed in on one object, attempting to squeeze every drop of possible detail through a high-tech telescope.

Binoculars give a direct connection to the night sky that's hard to achieve through a telescope. That's partly because binoculars are so simple and because viewing with two eyes is more natural than squinting through one eye. But it's also a function of their low magnification, their wide field of view, and the fact that you look directly toward your subject. All of these make it easy to correlate the binocular view and the naked-eye view. Telescopes, by contrast, tend to transport you into an alternate universe where familiar sights are completely absent — which has charms of its own, to be sure.

Over the years, I've written a number of blogs on binocular stargazing. To provide easy access from one to another, here's the complete list::

Nov 25, 2009	More on Scopes and Binoculars
Nov 15, 2007	Traveling Without a Scope
Sep 28, 2007	Big Binocular Messier Survey
Aug 31, 2007	Ridiculously Small Optics
May 10, 2007	Coda: Binoculars Versus Starblast
May 1, 2007	Binoculars Part III: One Eye Versus Two
Apr 27, 2007	Three Binoculars: Part II
Apr 23, 2007	A Tale of Three Binoculars: Part I

Fred Schaaf's Northern Hemisphere's Sky column for June 2010 discusses some phenomena that are visible in twilight, one of them being the Belt of Venus.

Fred simply mentioned the Belt of Venus, but I thought it needed more explanation.So I picked up a phrase from the internet, and described the Belt of Venus as "an arch of pinkish light above the shadow that Earth casts on the atmosphere opposite the sunset." Fred demurred, describing it as "pinkish border to Earth's shadow."

Unfortunately, I had no first-hand experience to fall back on. As an astronomy writer, I knew the term, of course. And reading about it in various sources, it was obvious that I must have seen it dozens or hundreds of times, but I had never recognized it.

Fortunately, it was clear the next few nights, so I was able to observe the Belt of Venus several times in a row, both in the evening and morning. The bottom line is that as usual, both Fred and I are right. It is a border to the shadow, but it also forms a striking arch — though an exceedingly low and broad one.

All you need to see for yourself is a clear evening and a site with an unobstructed eastern horizon. A hilltop, lakefront, or beach is ideal.


Right after the Sun sets, tear your eyes away from the arresting scene in the west, and look east to see a bright pink band opposite the Sun. This is the light of the sunset where you're standing being reflected off the atmosphere some 50 or 100 miles east of you, as shown above.


Three minutes later, the pinkish band has become fainter, but with a richer hue. Surprisingly, it has started to lift off the horizon. Now there's a thin band of bluish sky below the pink.


Six minutes after sunset, the dark blue band below the pink ribbon is beginning to take on shape and substance. It is now clearly rounded, taller in the middle than on the sides.

You are, in fact, seeing Earth's shadow. The Sun is now setting about 100 miles west of you. That light is still reflecting off the atmosphere to your east, but now some of it is blocked by Earth itself — even, just a little, by you standing on that hilltop. So the lowest part of the atmosphere opposite the sunset is no longer lit up.

Fifteen minutes after sunset, the pink has dissipated. But you can still make out Earth's shadow in the east as a huge, low hump of darker sky along the horizon — exactly the opposite of the normal situation, where the sky is brightest along the horizon and darker toward the zenith.

You are watching the onset of night. Soon, Earth's shadow will grow and darken dramatically, and eventually it will cover the entire sky, allowing you to look out at the greater universe that's usually hidden by the Sun.

Why is the Belt of Venus so little known? Partly it's because it's a fairly subtle effect. But even more, though people go out to watch sunsets all the time, they rarely think to turn away from the spectacular vista in the west and see what's happening on the opposite side of the sky.

Nobody else may care about blogs that I wrote three years ago — but I do, because I like to hyperlink to older blogs when I write new ones. So here, in case anybody's interested, is a list of all Stargazing blogs from 2007 through February 2010:

2010

Feb 21, 2010	The Belt of Venus
Feb 17, 2010	Thoughts about Pluto
Feb 16, 2010	Venus, Jupiter, and Vesta
Feb 14, 2010	Thoughts about Star Charts
Feb 7, 2010	Double-Star Resources
Jan 27, 2010	The Joy of Double Stars
Jan 13, 2010	My First Grazing Occultation

2009

Nov 25, 2009	More on Scopes and Binoculars
Nov 9, 2009	Paradoxical Messier 33
Nov 4, 2009	Chainsaw Astronomy
Oct 13, 2009	Doing Deep-Sky Wonders
Sept 29, 2009	Hiking Under the Stars
July 10, 2009	Light Pollution in North America
June 25, 2009	Light Pollution Per Capita
June 14, 2009	Is the U.S. Bright or Dark?
June 5, 2009	Ground Truth for the Light Pollution Atlas

2007

Dec 21, 2007	A Fun Year
Dec 19, 2007	The Scientific Value of Visual Observing
Dec 12, 2007	Holmes: Victim of Its Own Success
Dec 7, 2007	A Night in the Life of an S&T Editor
Nov 30, 2007	The Reliability of Visual Observing
Nov 20, 2007	The Amazing Comet Holmes
Nov 15, 2007	Traveling Without a Scope
Oct 11, 2007	Bye for a While
Sep 28, 2007	Big Binocular Messier Survey
Sep 20, 2007	Do the Planet Limbo
Sep 12, 2007	Calendars
Aug 31, 2007	Ridiculously Small Optics
Aug 29, 2007	Moonset Eclipse
Aug 23, 2007	Astronomical Twilight
Aug 16, 2007	Discussions Restored
Aug 14, 2007	Stellafane
Aug 9, 2007	Some Suburban Messiers
Aug 2, 2007	Twilight
Jul 30, 2007	Microsaccades
Jul 26, 2007	The North America Nebula
Jul 24, 2007	Comet Envy
Jul 20, 2007	Anticipating August
Jul 17, 2007	Pollution and Stargazing
Jul 13, 2007	Galaxies and Clusters and Comet, Oh My!
Jul 5, 2007	Strange Encounters Part II
Jun 26, 2007	Strangers in the Night
Jun 21, 2007	The Day the Sun Stands Still
Jun 14, 2007	Decisions, Decisions
Jun 8, 2007	Desk-Chair Science
Jun 1, 2007	Fear
May 25, 2007	Unexpected Connections
May 15, 2007	Big Sky
May 10, 2007	Coda: Binoculars Versus Starblast
May 1, 2007	Binoculars Part III: One Eye Versus Two
Apr 27, 2007	Three Binoculars: Part II
Apr 23, 2007	A Tale of Three Binoculars: Part I
Apr 13, 2007	Stars and Birds
Apr 4, 2007	How Brightly Shines the Moon?
Mar 31, 2007	Better Late Than Never
Mar 22, 2007	Measuring Skyglow
Mar 28, 2007	School Time
Mar 21, 2007	Dressing Up for an Evening Out
Mar 16, 2007	Equipment
Mar 14, 2007	Waiting for Sagittarius
Mar 7, 2007	The Meaning of Stargazing
Mar 5, 2007	A Spontaneous Star Party
Feb 26, 2007	Celestial Time and Human Time
Feb 22, 2007	Instant Astronomy
Feb 19, 2007	June in February
Feb 16, 2007	Stars and Snowflakes
Feb 13, 2007	Mercury Retrospective
Feb 9, 2007	Keeping Myself Honest
Jan 31, 2007	Hello World

Clyde Tombaugh discovered Pluto 80 years ago today. Coincidentally, I spent much of last week working on charts to help people locate and observe Pluto in 2010. And just two weeks ago, Kelly Beatty published an article describing new and exciting findings about Pluto. So this planet — or whatever you want to call it — has been on my mind a lot recently.

I've always been perplexed by the people who felt upset when Mike Brown and his team discovered another object both larger and farther from the Sun than Pluto. For people who don't remember, this object was first named 2003 UB₃₁₃, then Xena (after the Warrior Princess), and finallly and most appropriately, Eris, after the goddess of discord.

Ever since the Kuiper Belt was discovered in the 1990s, it's been apparent that Pluto is a member of this family. And it seemed extremely likely even then that it was only a matter of time until some Kuiper Belt object proved to be bigger than Pluto. But this doesn't detract from Tombaugh's discovery at all — quite the contrary!

It was obvious from the moment its orbit was calculated that Pluto was different from the other big planets. It seemed like a dead end, a footnote. Now we know that on the contrary, Tombaugh's discovery was a beginning, not an ending; he was a half century ahead of his time when he found the first KBO.

As for me, Pluto's luster certainly hasn't been diminished, since it's the only Kuiper Belt object that I'll ever see through the eyepiece of my own telescope — unless I someday acquire a monster Dob that's capable of splitting Charon from Pluto or spotting 16.9-magnitude Makemake, as Steve Aggas has done.

It's been several years since I last looked at Pluto. I guess I'll have to take a look this summer, if only as a quality check on my own charts. Pluto is in a unique position now, poised to enter the Small Sagittarius Star Cloud, which is truly crawling with 14th-magnitude stars of comparable brightness. I have no idea whether that will make Pluto harder or easier to spot.

As de facto webmaster for Sky & Telescope, I've been keenly aware of the events unfolding this week in the evening sky. Venus and Jupiter have been approaching an extraordinarily close conjunction, which will take place this evening. Meanwhile, Vesta, the brightest asteroid, is poised to thread the narrow gap between the spectacular double star Gamma Leonis and 4.8-magnitude 40 Leonis.

I knew I had to keep these events prominent on our website, but I didn't expect to see any of them myself, since the weather was forecast to be cloudy. So imagine my surprise when I looked out the window yesterday just before leaving work and saw a completely clear, dark blue sky!

By sheer coincidence, it was 15 minutes after sunset — just when I had been telling people to go out and look for Venus and Jupiter. So I grabbed the 7×35 binoculars that I always keep in my office, ran up to the top of the hill in the park across the street, and started to look. Sure enough, Venus was plainly visible to my unaided eyes, below the thin crescent Moon and a smidge to the left, just as advertised.

I couldn't see Jupiter with my eyes alone, but it was plenty obvious through binoculars — and seeming very far away from Venus. Hard to believe that it would close that gap in just 24 hours!

I went out after supper to look for Vesta. When I set up my telescope, the sky was still completely clear, but by the time Gamma Leonis was high enough to locate, the clouds had moved back in. And tonight it's going to be snowing. So although I've been tracking Vesta every clear night for the last week, I'll miss both of the climax nights when it's closest to Gamma Leonis.

Oh well, there's always another year. Seeing Venus and Jupiter so close together was an unexpected bonus; I can't ask for everything.

If you're lucky enough to have clear skies this evening, try to find a spot with an unobstructed west-southwest horizon and take a look for Venus and Jupiter as soon as the Sun has set. They should make a splendid pair through a small scope at 30× or thereabouts. And the crescent Moon above them is no slouch either.

Then, later in the night, take a look for Vesta. It's easy to see even in the smallest binoculars, and might just be visible naked-eye if your skies are really dark. Especially if you've never knowingly seen an asteroid, this is a chance in a lifetime. With the brightest asteroid of all at its brightest for the year, situated right next to a very prominent star, with yet another bright star to mark the way, you may never again find an asteroid so well placed for easy observation.

Click here for more information on Vesta and how to find it.

Oh, and if you have a telescope, don't forget to take a look at Gamma Leonis. 100× should be ample to split this double star into its bright golden components. In any case, enter a comment below and tell us how you did tonight.

As I wrote in a previous blog, I like to "do" Sue French's Deep-Sky Wonders column whenever possible. A few nights ago, I finally got a chance to start work on the March 2010 column — with a little trepidation.

Figuring out the illustrations for this article gave me a lot a heartache, because I knew I wasn't' got to be able to do it justice. Normally, Sue covers a small chunk of sky, making it relatively easy to cover the whole thing with one or two charts. This time, her targets stretched over more than 25° of sky, and I also wanted to include the "anchor stars" Castor and Pollux, making the coverage area even bigger.

To make matters worse, a number of the targets in this column are pretty faint, needing highly detailed charts for people who plan to locate them by star-hopping. Trying to cover such a large piece of sky at that level of detail would have consumed all the available pages, leaving no space for the text. Plus, it's really helpful to have photographs of some of the objects both as eye candy and also to give you hints what to look for through the eyepiece.

So I compromised, giving detailed coverage to the most challenging targets, but showing the rest just on a small map with stars to 6th magnitude. At the very least, that shows where everything is in the sky. But would it be adequate for star-hopping?

Not for me, it wasn't. The first two targets, Iota and 57 Cancri, are bright double stars, so they were easy. The galaxy NGC 2683 (which, by the way, I see only now I failed to highlight in yellow!) wasn't too hard either. It's right near a charted star, and at magnitude 9.8 it sticks out like a sore thumb in my 12.5-inch scope.

But I failed humiliatingly on the 11.6-magnitude galaxy NGC 2782, which is several degrees from any 6th-magnitude star. I had to revert to my backup charts (the Millennium Star Atlas) to find this little fellow. It wasn't especially subtle once located; I might have seen it on my first try — but I didn't.

I wonder how much all of this matters. A survey I did a couple of years ago indicated that most people who follow Deep-Sky Wonders either use Go To scopes or else use their own charts (printed or software) to star-hop, and don't rely primarily on the charts in the magazine. But after all, I'm a Deep-Sky Wonders reader too, so my opinions count at least a little. And although I do always have backup charts, I find it mighty handy when everything I need is right there in one place, in a format that's easy to hold up to an eyepiece.

What do you think?

A couple of weeks ago, I promised to write more about my ongoing search for double stars.

In the course of my double-star sessions, I've realized that what I really like about astronomy is the chance to be outdoors and interacting with nature. Sure, it's winter now, but there's no weather where I'd rather be inside than out. As for nature, its most visible manifestation at night is stars — I just love them! Some people say that looking at just plain old stars (as opposed to deep-sky objects or planets) is boring, but not me. There's something magical about turning my telescope to the sky and seeing all those pinpricks of light appearing as if out of nowhere; I never get tired of it.

That's probably why I love star-hopping; it gives me the maximum opportunity to interact with the stars, to actually utilize them as a means to an end. And if you want to star-hop to double stars, there's no substitute for the Cambridge Double-Star Atlas. Most star atlases mark doubles in some way, but few actually label them with their names, as the CDSA does.

If those aren't enough, Sissy Haas's book Double Stars for Small Telescopes is a virtually inexhaustible source, with complete data and thumbnail descriptions of more than two thousand multiple-star systems. And then, of course, Sue French's "Deep-Sky Wonders" column in every issue of Sky & Telescope almost always mentions a few double stars, including some offbeat choices that you're not likely to see listed anywhere else. That's the great thing about Sue — she covers all the warhorses, as well she should. But she also comes up with lots of weird, wonderful stars and objects that are completely off the beaten track.

Incidentally, the March issue of Sky & Telescope, which is now on sale, has a great article on double stars in Leo by Australian astronomer Richard Jaworski. And don't forget the amazing collection of double-star sketches found on Jeremy Perez's website.

My mother says that when I was a child, I would go on learning jags. I'd get obsessed with one subject, learn everything I could about it, and then go on to another. My stargazing career is a bit like that too — especially when I'm observing near my city home.

A decade ago, I was obsessed with observing all the Messier objects. This culminated in my online Urban and Suburban Messier Guide, a project that I finished before I started working at S&T. That project required obsession, because observing all the Messier objects from light-polluted surroundings requires lots of effort and concentration. I would often drive 45 minutes to my astronomy club's observing field, spend hours at the telescope, and return home exhausted in the small hours of the morning.

These days, I find short, frequent observing sessions more enjoyable than occasional, long, strenuous ones. Fortunately, there's an essentially inexhaustible supply of suitable targets. Unlike deep-sky objects, double stars are usually easy to find and observe. By analogy with hiking, my other favorite activity, a deep-sky object is like a mountaintop; it has a lot to offer, and once you've made the effort to get there, you want to spend a while. Double stars are like the stops on a nature trail. I linger at each one for just a minute or two, and then move on to the next. Deep-sky objects have many details to explore. With a double star, I just note the separation, the position angle, the relative brightnesses, the colors, and my overall impression — and that's really all there is to say.

The other beauty of double stars is that I don't have to travel far to see them. Thousands are visible and splittable even through small telescopes in the middle of a city. The Moon doesn't hurt them a bit, and they can even be viewed through thin clouds — which is just as well, considering the fickle weather we've been having recently.

I write more about double stars and the resources that I use to find them next week, or whenever I get a free moment. Bye 'til then.

My friends sometimes ask me why so few of my articles appear in Sky & Telescope. I explain that I'm often too busy editing other people's articles to write ones of my own. Moreover, I do write one very important piece of S&T every month: the Sky at a Glance page that appears in the center of the magazine, right before the all-sky chart. This might just be the single most labor-intensive page in the magazine — but it appears without a by-line.

It's particularly challenging to figure out which events to include in the calendar. I don't want to omit anything important, but I also don't want to send readers on wild-goose chases, searching for events that will be difficult to see or boring to watch. I had serious doubts about including the occultation of Antares on the morning of January 11th. Occutations of 1st-magnitude stars are fairly rare, and this one was going to take place over a heavily populated area — including our own office. On the other hand, it was going to occur in broad daylight over most of that area. All of my calculations indicated that it would be visible through a telescope despite the bright blue sky, but in my heart of hearts, I didn't really believe it.

So naturally, when it turned out to be clear that morning, I had to see for myself. I tried to set up a half hour before sunrise, as my own article advised, but due to complicated logistics, it turned out to be more like 20 minutes before sunrise. That turned out to be ample;Antares was still quite prominent through my 70-mm refractor even at a low 16X magnification. So I cranked the power up to 60X, and settled in for the long wait.

I didn't know exactly what to expect, because I was within a couple of mlles of the graze line — the border of the area where the occultation is visible. If my calculations were off by just a few arcseconds, the Moon might miss Antares entirely. And during a graze, the fact that the Moon isn't perfectly round becomes highly significant. A mile-high mountain at the right spot on the Moon's edge can move the graze line on Earth by a mile.

My best data suggested that the occultation would happen at 7:41, almost a half hour after sunrise. And as that time approached, Antares was (contrary to my fears) sitting nice and solid in the eyepiece. Then, at 7:39:45 — long before I expected — the star suddenly winked out. A couple of minutes later (I couldn't time it accurately), Antares re-appeared, presumably as I was looking through a particularly deep valley along the Moon's rim, glowed strongly for a few seconds, and disappeared again. Around 7:43 it appeared yet again, dimmed, brightened, winked a couple of times, and finally started to glow steadily again as the invisible unlit side of the Moon slipped away from it.

I've seen plenty of occultations before, but those were all simple affairs, where the Moon ran head-on over a star or planet. In such cases, the time of disappearance can be predicted to a split-second, and the star stays invisible until it reappears. In this case, I had only a vague idea when the occultation would start, and the brief halftime reappearance was a totally unexpected treat. It was far more exciting than I had expected.

Next time, I'll have my wits about me, and leave my voice recorder running trhoughout the event. That way, I can take scientifically useful readings, and sync the voice recorder to my watch after the whole thing is over. As it is, I have only the vaguest idea when anything happened. With such drama going on, I couldn't very well take time out to look at my watch!

A couple of years ago, I wrote a series of blogs comparing big binoculars and small telescopes. The subject has continued to fascinate me ever since, and I'm now planning to write an article about it in Sky & Telescope — tentatively slated for the May 2010 issue.

A couple of weeks ago, when two weekday nights near new Moon were forecast to be clear back-to-back, I took a day off from work to observe some more objects from Deep-Sky Wonders columns and to compare the three instruments shown at right: a pair of Fujinon 16x70 binoculars borrowed from Dennis di Cicco, my 70-mm f/6.9 refractor, and the Orion 4.5-inch Starblast.

I'm still working on the fascinating — though ultimately unanswerable — question of what sized telescope is equivalent to any given pair of telescopes. How good is the brain at combining the light seen through two separate eyes?

Pretty good, it would seem. Across the board, the images through the 16x70 binoculars are clearly superior to my 70-mm telescope at 16X. More surprisingly, I've actually found some cases where the binoculars beat the StarBlast running at 18X, using both higher magnification and much more aperture. In particular, the elusive outer loop of the Orion Nebula — the broad, extremely faint circle of light that stretches from Theta through Iota Orionis — is actually easier to see in the binoculars. Stay tuned for more details.

A few weeks ago I wrote about a session observing the objects described in the November 2009 "Deep-Sky Wonders" column. I also observed a fair number of objects from earlier columns, so it was a pretty strenuous night all in all.

To reward myself at the end, I decided to take a quick look at Messier 33, the Triangulum Galaxy. I have very fond memories of observing this galaxy in 2004, when I was editing an article on M33 by Alan Whitman for the December, 2004 issue of S&T. Whitman identified more than 30 separate emission nebulae and star clouds within this galaxy using his 16-inch scope, and I was pleased to be able to see more than a dozen of those through my 12.5-inch Dob. So I figured I'd be able to see a few of them just at a glance.

On the contrary! At first glance, M33 was just a large, formless blob. It didn't take long to identify NGC 604, the brightest nebula, but after that I barely knew where to begin. Even the spiral pattern wasn't exactly obvious. And then I remembered just how long and hard I'd worked to find those dozen objects, with my labeled photo in hand.

M33 is paradoxical indeed. It's the 4th-brightest galaxy in the sky as measured by total brightness, but because of its relatively low surface brightness, it's extremely hard to see in light-polluted surroundings. Some beginners can't see it even through big telescopes under dark skies. It shows a wealth of detail, but picking out the individual components can be amazingly hard.

If you want to try identifying objects within M33 yourself, I've made Alan Whitman's article available as a 300-Kb PDF. Click here to read a summary of the article and to download the PDF, complete with a labeled photograph. That's what I'll be using next time I rendezvous with M33 and my 12.5-inch Dob.

Eight years ago, Sky & Telescope ran a short piece by a stargazer who had cut down a bunch of trees to get a better view of the sky. It provoked a startling number of outraged letters.

Chainsaw astronomy seems to be very controversial, yet the subject arises over and over. Truth be told, in many parts of the world — including my own — trees are the single biggest enemy of stargazing. Sure, light pollution diminishes what you can see, but trees stop it completely. In its natural state, inland New England would have nary a view of the night sky except at the edge of rivers, lakes, and swamps -- and barely even there.

I find myself completely unsympathetic with both extremes of the debate. On the one side, there are people who say they would never cut down a tree just for convenience. On the other, those who say that it's my property, and no tree hugger is going to stop me from doing what I want with it.

I do think that trees demand respect — as does every living thing and even, to some extent, everything inanimate. If you brutalize the world around you, you also brutalize yourself. But I don't view trees as sacred — not as a general rule, anyway. In some ways, that seems just as irresponsible. It's copping out, failing to engage with the concrete reality of individual trees.

Mind you, certainly trees are indeed sacred, though it's we who make them so. At my preferred observing site at my country home, the entire northern sky is blocked by a huge sugar maple that was probably planted when the house was built. But cutting it is completely unthinkable. My grandparents preserved it when they bought the house in 1930, and it's my duty to preserve it for my grandchildren — when and if they are born. It goes beyond my own personal likes and dislikes – even beyond my extended family. It's a link to the boys who lived in that same house and loved that same tree before they went off to fight and die in the Civil War.

On the other hand, I'm perfectly willing to cut down the trees at far end of the field that block my view directly to the south, where it matters most. Those trees are barely older than I am; when my father was a child, those woods were sheep pasture as far as you could see. If I don't cut trees down, then the field will slowly, inexorably, grow in from the edges, and there will be no field at all for my grandchildren.

Mind you, even those trees I'm not about to simply slaughter. I won't cut them faster than I can burn them in our fireplace. At the current rate of progress, I figure it will take me a decade or more to get an extra 15 degrees of unblocked horizon. But that's OK. It's foolish to be in a hurry when you're dealing with organisms whose life spans are measured in centuries.

It's sobering to think that the beavers who recently moved into the swamp below our house have killed more trees in three years than I have in my whole life. Then again, it's a full-time occupation for them, and just a hobby for me.

Sky & Telescope readers often comment how much they enjoy reading Sue French's "Deep-Sky Wonders" column. I certainly agree, but to some extent, that's missing the point. Sue is a good enough writer to make her column entertaining as armchair reading, but its real purpose is to be used outside, at night, by the side of a telescope.

Since I'm Sue's regular editor, I make a point of "doing" her columns whenever I get a chance. Among other things, it lets me make sure that the charts and illustrations that I prepare are adequate for finding the things she talks about. And in any case, it's hard to imagine a better way to spend an hour or two.

I particularly enjoyed the column in the November 2009 issue because of its variety. Sue starts out exploring Pegasus I, a galaxy cluster with a couple of very prominent members (NGC 7619 and 7623) and a whole host of fainter ones. I was pleased that, using my 12.5-inch Dob last Sunday at my semi-dark second home in rural NY, I was able to log at least a strong "maybe" for all the ones listed in the article.

Sue sometimes fails to get the respect that she deserves from hard-core deep-sky observers -- perhaps because she spends so much time with her 4.1-inch refractor, or perhaps because she never goes out of the way to took her own horn. In fact, she generally sees more through her 10-inch scope from her far-from-dark backyard than I can through my 12.5-incher at a considerably darker site. Then again, she probably devotes ten times as much time as I do to observing, so her superior skill is hardly surprising.

After I'd spent more than an hour straining to see the 14th-magnitude galaxies described in the November Deep-Sky Wonders, I got to unwind with a lovely succession of relatvely easy double stars, the magnificent carbon star TX Piscium (which I often view), and a charming asterism that I never would have stumbled on if Sue hadn't mentioned it.

But don't take my word for it. If you own a telescope, why don't you try "doing" Deep-Sky Wonders yourself? Sue almost always lists one or more targets that are easy for novices to enjoy as well at least one target that's bound to be a challenge for even the most experienced observer.

Astronomy is an unusual hobby; it snares lots of different kinds of people for many different reasons. For me, it was a natural outgrowth of my love of the outdoors. The one activity that I love even more than stargazing is hiking in the mountains. And combining hiking and stargazing is best of all!

Most people who hike in the U.S. Northeast would agree that September is the best time to do so. The oppressive heat and bugs of summer are gone, the chance of rain is low and the chance of snow even lower, yet the days are still reasonably long. So for the last weekend in September, I took Friday off to do a three-day hike that I'd long dreamed of and never attempted. For those who know New Hampshire's White Mountains, I went north up the Bonds, west across South Twin and Garfield, and then south down the Franconia Range. Many geologists believe that the striking horseshoe-shaped ridge that I followed is the remains of an ancient volcanic caldera.

The weather proceeded exactly as forecast. Friday started cloudy and drizzly, then turned crisp, cool, and windy. Saturday was predicted to be perfect hiking weather, which it indeed turned out to be — cloudless skies, crystal-clear air, gentle breezes, and temperatures around 40°F. (That's T-shirt weather when you're doing strenuous hiking.)

I spent Friday night at Guyot Shelter, high up in the mountains and as far from civilization as you can get in New Hampshire. I was eager to rise early for two reasons. I wanted to take advantage of Saturday's weather and hike as far as possible. And since this was first-quarter Moon, the sky would be truly dark before dawn — giving me a great chance to see the zodiacal light. And indeed, when I awoke around 4:30 on Saturday morning, there was the zodiacal light shining between two trees — as fine a view of it as I've had for several years.

Packing up as quietly as I could to avoid wakening my shelter-mates, I hiked up to the main trail and started to cook breakfast before the first sign of dawn. I could only see the narrow strip of sky above the trail, but that was enough! The Milky Way from Cassiopeia to Auriga ran directly overhead, intricately veined with dark lanes, with the Double Cluster blazing in its center. Quite a backdrop for breakfast!

By the time I was actually hiking, the sky was getting light. Shortly afterward, I emerged above treeline on Mount Guyot to the most glorious view imaginable. Orion and Canis Major were still prominent in the south, while Mars, Castor, and Pollux made a perfect arc overhead. But Venus dominated the view, blazing above a magnificent sunrise glow that stretched the entire length of the eastern horizon. I put on my down jacket and mittens and snapped endless pictures as the sky grew brighter and the mountains around took on a rosy hue. In the lowlands to the north, isolated hills rose out of a sea of fog as far as I could see.

I started to hike again, ducked into the trees, and by the time I emerged above treeline again on South Twin, the Sun was well above the horizon.

Saturday was a great day of hiking by any standard — I ended up walking 14 hours though some of the finest scenery in the East, at one of the loveliest times of year. I crossed six mountaintops, each with a wonderful view, each very different from all the others. And I certainly got a good workout! But none of the time that I spent walking during broad daylight came close to the magic of those hours between the first sight of the zodiacal light and the disappearance of the last stars.