Hack29.Plan and Prepare for a Messier Marathon

Hack 29. Plan and Prepare for a Messier Marathon

Locate, observe, and log all 110 Messier Objects in one night.

The 18th-century French astronomer Charles Messier (pronounced MEZZ-ee-yay) lived for finding comets. Every clear night, he was out with his telescopes, trying to be the first to identify each new comet. But Messier had a problem. It's very difficult to tell the difference between a dim comet and many other dim astronomical objects. The only way he could know for sure that he'd found a new comet was to observe the object over several nights. Over that period, a comet moves relative to the background stars, while other objects remain fixed in position.

On the night of 28 August 1758, Messier was looking for comet Halley on its first predicted return when he happened across a dim object in the constellation Taurus that looked very much like a comet. He studied that object intently over the next several nights, only to find that it didn't move against the background stars. Disgusted at the waste of time, Messier decided to create a list of these obnoxious fixed objects that masqueraded as comets so that he and other observers could avoid wasting time looking at them in the future. He carefully logged the position of the object, and recorded it as Messier Object 1, or M1. (That object, now known as the Crab Nebula, is one of the most famous astronomical objects.)

Over the years, Messier added to his list of objects until it eventually included 103 objects, one of which was a duplicate. The irony is that in creating his list of objects to be avoided by comet hunters, Messier unintentionally created a list of the finest objects in the night sky. (The limitations of Messier's equipment meant that he could see only the brightest objects, which are easy and rewarding targets for observers with modern equipment.) Messier would have wanted to be remembered for the many comets he discovered; instead, that aspect of his career is almost entirely forgotten, and he is famous nowadays for his list of objects.

The Messier List now contains 109 or 110 objectsdepending on whose argument you find most persuasive. The "extra" objects were all observed by Messier, but not recorded in his list for one reason or another. Nearly all modern amateur astronomers who are interested in deep-sky objects begin with the Messier list. Many amateur astronomers take years to observe all of the objects on the Messier list. Others complete it faster.

For a few nights a year, centered on a new moon date in mid-March to early April, it is at least theoretically possible to view all 110 Messier Objects in one night, starting at dusk and ending at dawn. Those brave (or foolish) enough to undertake this quest call it a Messier Marathon (MM). And a Marathon it islocating, observing, and logging an average of one object every five minutes or so over a span of about 10 hours.

2.20.1. Planning Your Messier Marathon

Planning is the first key to running a successful Messier Marathon. It's important to think through everything in advance, because you'll have no time to spare when you actually begin running the Marathon.

2.20.1.1 Choose a date

The first thing to decide is when you'll run your Marathon. In one sense, there's not much to decide, because a full Messier Marathon is practical only at or near a new moon that occurs from mid-March until early April, and the best opportunity to log all 110 objects occurs only when the new moon is in late March. Table 2-7 shows the new moon dates and Messier Marathon weekends for the next 10 years.

New moon times are specified in days and tenths of days in Universal Time (UT). Depending on your location, the new moon may occur on the prior or next day local time. For example, if you are in the Eastern Standard Time zone (EST), the new moon in the early morning of 6 April 2008 UT occurs in the late evening of 5 April 2008 local time.

Table 2-7. Optimum Messier Marathon dates for 20062015

Year	New moon(s)	Primary weekend	Secondary weekend(s)
2006	29.4 March	25 March	1 April
2007	19.1 March	17 March	(none)
2008	7.7 March 6.2 April	8 March	29 March 6 April
2009	26.7 March	28 March	21 March
2010	15.9 March	13 March	20 March
2011	4.9 March 3.6 April	2 April	5 March
2012	22.6 March	24 March	(none)
2013	11.8 March	9 March	16 March
2014	30.8 March	29 March	(none)
2015	20.4 March	21 March	(none)

Not all of these Marathon nights are equally desirable:

• For Marathon dates earlier than mid-March, it is nearly impossible to view all 110 objects because the late-rising objects, particularly M30, are lost in the morning twilight.

• For Marathon dates later than late March, it is nearly impossible to view all 110 objects because the early setting objects, particularly M74, are lost in the evening twilight.

Accordingly, the best years to run a Messier Marathon will be 2006, 2009, and 2014. In 2007, 2010, 2012, and 2014, it may be possible to log all 110 objects, but it will be very difficult because the new moon occurs too early in March and not early enough in April. In 2011, it may be possible to log all 110 objects in early April, but the early-setting evening objects will be extremely difficult. In 2008 and 2013, it will be nearly impossible to log all 110 objects because the new moon occurs much too early in March and much too late in April.

Latitude is also a factor because evening twilight ends later and morning twilight begins earlier at higher latitudes. The ideal latitude for running a Messier Marathon is about 25°N. If you are at 40°N or higher, it is very difficult or impossible to bag all 110 objects, even if the new moon occurs ideally in late March.

Group Marathons are scheduled on weekendsusually a Saturday nightbecause most people aren't able to get away during the week. Unfortunately, the best weekend date may be too early or too late in the season. It may also be several days from the new moon, which means moonlight may intrude on your Marathon. Moonlight interferes with finding objects, so if your schedule permits and you don't mind Marathoning by yourself (or you have some like-minded friends) it's best to run your Messier Marathon on the date the new moon actually occurs, or at most one or two days either side of that date.

Weather may also interfere, of course. March and early April have predictably unpredictable weather in many parts of the world. The best chance to complete your Marathon despite weather is to bracket the new moon date. If possible, reserve the site and your lodging for two or three nights before and after the new moon. If the weather forecasts are terrible for the early part of the period, you needn't actually travel to the site early. If the weather is clear and you complete your Marathon early or on time, you needn't stick around if the forecasts are bad for the remainder of your scheduled stay. You may be lucky and get in an evening or two of observing after completing your Marathon. You may even be able to run a second Marathon if you didn't bag all 110 objects on the first go-round.

If you find yourself clouded out one evening, but the forecast is for clearing weather, do a "calendar-day Messier Marathon." That is, begin your MM at midnight, knock off at dawn, and then come back that evening to log more objects from nightfall until midnight. You can't really claim to have done the traditional Messier Marathonthat 15-hour nap in the middle splits your effort into two half-Marathonsbut you will have logged all or most of the Messier Objects in a single day, which is a major accomplishment in itself. And, if the weather remains clear that night, there's no reason you have to stop at midnight. You can continue working, and complete a traditional Messier Marathon at dawn the following morning.

2.20.1.2 Choose your observing site

A good observing site is critical to the success of a Messier Marathon. Three primary considerations define a good Messier Marathon site:

Unobstructed horizons

Of the three, by far the most important consideration is having unobstructed horizons. To complete the Marathon, you must observe several objects that set early in the evening twilight and several more that rise late in the morning twilight. Your first goal should be to find an observing site with eastern and western horizons as near 0° as possible. Each degree of obstruction costs you about four minutes that you can't afford to lose. For example, if the site has a 15° obstruction on the western horizon, evening objects set one hour earlier, while the sky is still too bright to observe them. The same holds true, in reverse, for obstructions on the eastern horizon. The late-rising morning objects are difficult enough to observe if you have a 0° eastern horizon. Every degree of obstruction on your eastern horizon makes you wait four extra minutes for the object to rise, as the sky grows brighter with each passing minute.

The southern horizon is also important, although not as critical as the eastern and western horizons unless you are observing from a high northerly latitude. Southerly constellations such as Sagittarius and Scorpius culminate well after daylight on Marathon morning and are still quite low at the time you need to observe them. A good Marathon site will therefore have a southern horizon obstruction as close to 0° as possible, and certainly not more than 4° or 5°. The northern horizon is the least critical, although ideally it should be obstructed no more than a few degrees. Don't necessarily rule out an otherwise-ideal site that has an obstructed northern horizon, particularly if you can eliminate the obstruction easily by moving your scope temporarily.

Freedom from light pollution

An ideal Marathon site has pitch-black skies, no light domes, and no local lights. Alas, such sites are rare nowadays, particularly on the US east coast and other heavily built-up areas, so you may have to compromise. Look for a site with skies that are no worse than Bortle 4 (http://cleardarksky.com/csk), and try hard to find a Bortle 3.5 or better site. Avoid sites with intrusive light domes, particularly to the south. Although there's nothing you can do about general light pollution or light domes, don't rule out an otherwise acceptable site because of local lights. You may be able to use screens or other workarounds to block local lights. If you ask nicely and explain why, people are often willing to turn them off for you.

High elevation

High elevation is desirable for several reasons. First, the air blanket between you and the night sky is thinner, which makes it easier to locate and observe dim objects. Second, being at high elevation gets you above air pollution, humidity, low-lying clouds and haze, and other muck, which makes it much more likely the sky will be transparent near the horizons. Third, high elevation minimizes the effects of the light domes produced by nearby cities and other built-up areas. (Even a small town 20 miles or more away can produce a noticeable light dome at a dark site.)

An acceptable observing site is likely to be at least 20 miles from the nearest town of 10,000 or more population, and several miles from smaller population centers. For many of us, that means having to travel to find an acceptable site and to find lodging for the duration of our stay. Rather than simply drive around randomly, hoping to stumble across a good site, contact your local astronomy club and astronomy clubs in the area where you propose to run your Marathon. You may find that other amateur astronomers have already done all the work for you and can suggest the best sites in the area. For that matter, they may already have scheduled a Messier Marathon that you can join.

Once you've chosen a site, particularly if it's on someone else's recommendation, make a preliminary site visit to do a detailed evaluation. If you have a scope with digital setting circles (or can borrow one), take it along and use it to map the horizon from the actual observing pad. Level the scope, point it straight north, and put the finder crosshairs at the top of the highest obstruction in view. Record the obstruction at 0°. Rotate the scope 5° or 10° degrees to the east, and repeat the elevation measurement all the way around until you return to 0°. You'll need this horizon map when you plan your observing sequence and schedule.

If you don't have access to a scope with DSCs, you can temporarily turn any scope into a makeshift theodolite using a large protractor, a compass, a spirit level, a piece of thread, and a small weight. Use the compass to determine azimuth (don't forget to adjust for local declination), the level to determine baseline altitude, and the protractor with the weighted thread to determine the altitude of obstructions. With care, you can make measurements accurate to a degree, which is more than sufficient. You may need one person to do the sightings while another notes and records the elevations at each point.

Alternatively, you can use a digital camera to produce a panoramic photo that covers the entire horizon. From that photo you can closely estimate the altitude of obstructions around the horizon.

Make sure to get permission to use your chosen site on the dates you plan to be there. If you will be staying at a hotel, make lodging reservations well in advance. Spend some time during your initial site visit touring the immediate area to locate restaurants and similar conveniences. Don't assume they're open all the time. Restaurants and other facilities near remote observing sites may close down for part of the year. Sometimes, a hotel is open year-round, but its restaurant closes during the off-season. Ask. Plan ahead for medical emergencies. Make sure you know where the nearest hospital is (and how to get there), how to contact emergency services, and how to describe the route to your site.

Make sure you know how to get to the site yourself. More than one would-be Marathoner has been embarrassed by his inability to find the site the day of the Marathon. Back roads can be confusing, and the last thing you want is to be driving around trying to find your observing site as the clock ticks down. If the site is difficult to locate, map it out during your preliminary visit. Record distances and turns, or use a GPS to set waypoints. And don't overlook finding your way out. Even if you have detailed directions for find-ing your way in, it's easy enough to become lost trying to find your way out, particularly just after dawn the morning after.

2.20.1.3 Develop your own sequence and schedule

It's important to develop a sequence and a schedule for the Messier Marathon. The sequence specifies the order in which you plan to observe the objects. The schedule specifies the time you plan to observe each object. Both are important because during the Marathon you are attempting to observe 110 objects, all of which are moving targets.

• The sequence is important because some objects set early or rise late, leaving you only a short window to observe them. Other objects rise early and set late, and can be observed at any time over a period of many hours. The sequence accommodates this by assigning first priority to observing time-critical objects. The sequence is most important for the dozen or so objects at the start of the Marathon and the final half dozen objects at the end.

• The schedule is important because it helps keep you on track. By assigning a specific time to each object, you know at a glance whether you are behind, ahead of, or on schedule. Without a schedule, you might spend so much time observing a few earlier objects that you run out of time to observe later ones. When you're ahead of schedule, it's nice to know that you can relax a bit without worrying about missing later objects. It's good to know when you're behind schedule, too, because that allows you to push harder while there's still time to catch up.

The best sequence is a personal matter. It takes into account not just the rise, culmination, and setting time of the objects, but your own preferences, the horizons of your site, and so on. The best way to develop a personalized sequence is to start with one of the many published sequences and modify it to suit your own situation. For example, a published sequence may assume 0° horizons all around, and have a later-setting object later in the sequence than one that sets earlier. But at your site, the first object may in fact set earlier because of your horizons. Start with one of the published sequences that appeals to you, and check it against your own situation by using your planetarium software [Hack #64] to verify the local times for rise, culmination, and set for each object, taking your horizons into account.

Here are some good sources for standard sequences:

• Harvard C. Pennington. The Year-Round Messier Marathon Field Guide. Willmann-Bell, 1997. This is the best book we've found for Marathoners. It covers every detail of planning, preparing for, and running a Messier Marathon, and includes sequences not just for the main Marathon, but for mini-Marathons every month of the year. Pennington provides detailed star charts, with Telrad circles, to help you locate each object quickly. This book is available only from the publisher directly, Willmann-Bell (http://www.willbell.com), and it should be a part of any Marathoner's equipment.

• Don Machholz. The Observing Guide to the Messier Marathon: A Hand-book and Atlas. Cambridge University Press, 2002. This is a renamed second edition of Machholz's original The Messier Marathon Observer's Guide. It includes more background information than Pennington's book about Charles Messier and his contemporaries, Messier's quest for comets, the Messier catalog itself, the history of the Messier Marathon, and so on, but we prefer Pennington's book as an actual observing guide.

• The SEDS Messier Marathon Search Sequence page includes links to numerous sequences and other resources (http://seds.lpl.arizona.edu/messier/xtra/marathon/marathon.html#sequence).

Treat your sequence as tentative rather than absolute, and be prepared to depart from it as necessary while you are actually running the Marathon. Something as simple as an errant cloud bank may make it necessary to change your observing order, but if you depart from your sequence make sure it's for good reason. On Marathon night, it's easy to convince yourself to change your sequence. Just remember that you put a lot of work and thought into developing the sequenceor at least you should haveso an on-the-spot decision may lead you astray.

Nearly every Marathoner uses a planned sequence, but many fail to attach a schedule to that sequence. We think a schedule is essential to help you stay on track and to avoid missing objects. You can make your schedule as detailed as you wish. We schedule down to the individual object level, but there is an argument of simplicity to be made for scheduling at the level of small groups.

Whichever way you do it, sit down and think through the list. Try to determine how much time you need to spend on each object or group, and then assign it a time or range of times within the sequence that reflects how long you expect to need to find it. It's helpful to have experience in observing all of the objects because different people "trip over" different objects. For example, one person may be able to locate the planetary nebula M76 in seconds, every time. Another equally skilled observer may have practiced finding M76 repeatedly, but may still need five minutes to locate it, every time. It's just a personal quirk, but a few of those can wreak havoc on a schedule if they're not taken into account.

2.20.2. Preparing for Your Messier Marathon

Preparation is the second key to running a successful Messier Marathon. The Messier Marathon is a race against time, so the better prepared you are, the more likely you are to succeed. You can begin preparing at any time before Messier Marathon night, but the best time to begin preparing for the next Messier Marathon is immediately following the last Messier Marathon. We suggest you do the following during the period leading up to your first attempt at a Messier Marathon.

2.20.2.1 One-year lead-up

During the several months to a year before the Messier Marathon, take the following steps to prepare for Marathon night.

Observe all Messier objects

The last thing you want on MM night is to be looking for an object you've never seen before. In the months leading up to the Marathon, you should observe all 110 objects, ideally several times each. Get familiar with the appearance of each object and where it is positioned within its constellation and relative to other constellations and guidepost stars. In particular, become intimately familiar with the galaxies in the Coma/ Virgo cluster, which Marathoners call the "Coma/Virgo Clutter." Many Marathoners have had their hopes dashed by becoming lost in Coma/ Virgo. Practice locating and viewing objects that are setting low in the evening twilight and objects that are rising low in the morning twilight.

Memorize as many objects as you can

Memorize the locations of as many objects as possible to save time on MM night. For example, you should be able to locate all three objects in Orion (the nebulae M42, M43, and M78) from memory, without referring to your charts. That allows you to locate, view, and log three Messier Objects in only a minute or two, saving time for more difficult objects. Memorize other easy objects, such as the three Auriga open clusters (M36, M37, and M38), which you can bag with your binocular in 30 seconds flat. With some effort, you should be able to memorize the locations of at least 30 to 50 objects. Being able to pick off those objects quickly eliminates a great deal of time pressure when you are searching for other objects.

There is a specialized Messier Marathon called M³, or M-cubed, for the Memory Messier Marathon. You run this Marathon without charts or a computer, without a sequence list or a schedule, in fact without anything except your binocular, telescope, and log sheets.

Secure your MM observing site

Unless your regular observing site is extraordinarily good, both in terms of darkness and horizons, you'll probably need to run your MM from a special site, which may be some distance from your regular haunts. Well before MM night, visit potential sites to determine their suitability in terms of horizons, light pollution, and local lights. Ideally, run at least one observing session at the prospective site. Make sure you have the site reserved for MM night and, if necessary, make lodging reservations well in advance.

Finalize your sequence and schedule

There is no one best MM observing sequence. The best sequence depends on many factors, including the date of your session, the latitude of your observing site, local twilight times, horizon obstructions, and so on. Start with one of the published sequences, but modify it to suit your own conditions. Pay particular attention to the early evening objects and the final morning objects, for which twilight times and horizons are critical. Use your planetarium software to determine what the elevations of critical objects will be on MM night and how those elevations compare with the actual horizons at your chosen site.

Develop a proposed schedule, deciding how much time to devote to each object, taking into account the difficulty of each object based on its position and the status of other objects nearby in the sequence. For example, if you are running a Marathon in early April, the evening objects set very early. You don't want to spend 15 minutes trying to locate M74 setting in the evening twilight if that means you'll miss your opportunity to log several other easier evening-setting objects. Instead, sequence and schedule the easier objects first. Once you have them logged, you can return to M74.

Learn your equipment

MM night is the worst possible time to break in new equipment. Decide what equipment you will use well before the MM, and practice with it extensively. If you have your eye on a new right-angle, correct-image finder, for example, buy it now and get comfortable with it before MM night. If you don't have a Telrad unit-power finder [Hack #53], get one as soon as possible and learn to use it. A Telrad is, if not essential, at least extremely useful for a Messier Marathon.

Marathon night is likely to be cold except at the most southerly latitudes. Don't underestimate the sheer physical demands of a long observing session in cold weather or the importance of cold-weather gear and preparations. Test your readiness for a long, cold observing session well before Marathon night by actually doing a long, cold-weather observing session. If your gear or preparations are inadequate, the time to find out is before Marathon night [Hack #4].

Prepare your charts

Many amateurs have several sets of charts, ranging from overview charts like the Orion Deep Map 600 to mag 6 star atlases, and on to more detailed charts like Sky Atlas 2000.0, Uranometria, and the Millennium Star Atlas. None of these are ideal for a Messier Marathon. All provide too little or too much detail, and none focuses on the problem at handlocating Messier objects quickly.

Rather than use any of these standard charts, we recommend using your planetarium software to produce custom charts for each object, one per page. Set your planetarium software to the coordinates of the observing site. For each object, reset the planetarium time to the approximate time you expect to be locating the object, so that the chart is oriented as the sky will be at the time you observe it. Pre-plan your Telrad placements and star hops, and print those circles right on your custom charts.

Run at least one practice MM

Although it's possible to log all Messier objects in one night only during the March/April MM window, you can do a "mini Messier Marathon" on a night near a new moon at any time of year. The number of Messier objects visible varies with latitude and from month to month, with minima in mid-May to mid-June and early September, but at least 88 objects are possible any dark night from latitudes as high as 40°N. The best way to practice for a MM is to run a MM, so we suggest you run at least one all-night practice MM session in the months leading up to MM night.

2.20.2.2 One-month lead-up

The new moon weekend a month prior to the MM is a perfect time to do a final trial run, ideally a full practice Marathon. Morning objects are still impossible, but evening objects are higher than they will be on Marathon night. Practice bagging them in the evening twilight. Do at least one full run through the Coma-Virgo Clutter. It will probably be as cold or colder than Marathon night, so now is the time to do any tweaks necessary to your cold-weather gear and preparations.

2.20.2.3 One-week lead-up

Now is the time for final preparation. Check your equipment. Make sure your scope is collimated and your optics are clean. Replace the batteries in your flashlights, Telrad, mount motors, and so on. Get in at least one final practice observing session, focusing your attention on whichever objects or groups are difficult for you.

2.20.2.4 One-day lead-up

Relax. You're as prepared as you're ever going to be. There is such a thing as over-preparing. Get your equipment packed up and checked off against your checklists. Charge your notebook, cell phone, and other equipment, and don't forget to charge your spare batteries. Say goodbye to your family and make sure your life insurance policies and will are up to date. It's almost show time.