3 Lunar Software Packages Compared

For almost two decades, lunar observing has been the forgotten step-child of astronomy. New atlases and guide books for DSOs have come out nearly every year, while the Rukl Atlas of the Moon is no longer even printed (and there is no sign of the new Rukl or any other new atlas). In the same manner, there has been a ton of software written for telescope design, DSO planning, planetarium programs, and almost anything else not related to the moon. But in the last couple of years, interest has swung back to lunar observing. And with that has come three new software packages for lunar observers. Last year I began working with these three lunar software packages:

• Lunar Phase Pro (LPP) $40
• Virtual Moon Atlas (VMA) Free
• Lunar Map Pro (LMP) $89

This review will attempt to list the strengths and weaknesses of each along with a comparison. However I tested the programs whenever I had free time. And since RITIs program requires you to have the original cd present, I wasnt always able to work with it. Therefore, most of this review will focus on the first two with comments about the third where appropriate. LMP will be reviewed in-depth in a later article.

All three programs installed without any major problems. My testing was assisted by two lunar novices who helped me by installing, using and then removing LPP and VLA on their own systems. The only difficulty reported was when one of the testers had a brief problem finding his longitude and latitude for LPP and VLA. (LMP does not require this input since it does not correct for libration --- LPP allows you to enter multiple sites, all corrected for their own libration). VLA is downloaded from the website, and full installation requires manually running seven self-extracting zip files. LPP and LMP install automatically from a CD. Both testers also removed the programs from their computers at the end of the testing. Both LPP & VMA did a fairly good job of uninstalling. Both programs left the directory structure intact, but it was easily removed. Norton reported LPP had cleaned up all registry entries, while VLA left only one behind. I removed and reinstalled LMP on my own machine, and found it did not leave as clean an uninstall as the other two. However, Norton was again able to remove the remaining registry entries.

Service & Support

LPP and VMA are supported by their authors. With LPP there is a Yahoo support group as well. While I was not able to measure response times for all three packages, I did notice that a bug was recently reported to Gary Nugent (LPP author) on the Yahoo group. A fix was released that same day. The individual who had reported the bug commented that Gary had fixed it in 2 hours and 49 minutes from initial report to the time the new download was available! YMMV.

Patrick Chevalley, the author of the software half of VMA is also the creator of Cartes du Ciel, an excellent star-charting program. He has a good track record of listening to the desires of end-users and incorporating new features. He has done this with CdC and now with VMA.

LMP is a relative newcomer and does not have a proven track record in this area. I have written to them several times, and usually received a response. However the responses were reasons why they couldn' t incorporate a given feature (libration). They did not respond to a request that they remove the ridiculous copy protection scheme. However I understand that since I wrote, they have allowed some to purchase an additional key that allows them to use the program on one machine without having the original install CD present.

System Requirements

LMP states they require 300 MHz, 96MB RAM recommended, Windows 98 and later, 160 MB (minimum 85 MB) of free disk space.

I tested the programs on a Compaq Presario laptop with a 1.4 GHz P4 and ATI Mobility Radeon 7500 graphics running XP. The second system is an older Celeron 733 running Windows ME. My two helpers had briefly installed LPP and VMA on a similar Compaq laptop, and a desktop system running a 2.0GHz P4 and Windows 2000. I looked primarily at the two laptops for performance comparisons, as it seems these programs would be most helpful on a system that can be taken to the telescope. In both cases LPP was significantly faster than the other two programs. Pan and zooming the lunar map was quick and responsive. VMA would have a 2-3 second delay before it began the first pan or zoom. Subsequent zooms or pans in the same direction were much quicker. But if you tried to pan in a different direction (up-down instead of right-left), there was again a delay of several seconds. If you went back to the first direction, there was again a delay. In going to configuration or other screens, there was a delay with VMA. I am used to windows snapping open with the laptop but this did not happen with VMA. However both programs were faster than LMP. LMP' s slowness is confusing when you realize it is not correcting for libration but simply posting a map on a sphere and portraying it at neutral libration.

All three programs require OpenGL to operate best. Bitmaps are available for systems not having this capacity. LPP allows the user to switch between the 3D view and a flat Mercator projection bitmap. The Mercator projection does not have North/South Pole views or libration correction and libration animation.

Lunar Phase 3

Do you remember when you were a kid and wanted one of those fancy Swiss Army Knifes? There in one red package you could have a saw, scissors, tweezers, toothpick, bottle opener, file, slotted and philips screwdriver and even a knife blade! Well LPP doesn' t have the fat red case, but it does take the same approach to Lunar software.

The opening screen shows the moon with current phase and the correct libration, with a marker for the point on the lunar limb that currently is at maximum libration. This view can be set for flipped or inverted views, depending on what you use to observe the moon. Around that are listed the time and dates for the four different quarters (new, half, full, half), percentage of the moon currently illuminated, age, current distance, RA & DEC, Alt & Az, angular diameter, time and date of apogee and perigee, time of today' s moonrise, moonset and transit, sunrise, sunset and sun-transit time, twilight start and ending time (civil, nautical and astronomical) and colongitude. Additionally, a table of libration data adds North-South libration, East-West libration, degree of maximum libration, position angle for that libration and the moon' s current position angle. But even more amazing is that all of this data is clear and available at a glance, due to the clear layout employed.

A dropdown menu accesses features to find lunar eclipses within a specified timeframe, display a calendar with phase for each day, lunar features database, Equinox & Solstice dates, Internet links, basic lunar data and other features which will be described below. As I mentioned, the opening screen tells the current libration, both graphically and in table form. Both LPP and VMA correct their maps for the current libration. LMP does not, which means that when you are observing near the lunar limb, LPP and VMA will show you what is actually visible, and LMP will not. This is a major difference and one of LMP' s biggest problems. But while both LPP and VMA indicate the correct libration, LPP takes it several steps farther. Clicking on the Moon Explorer button brings up a large image of the moon with current libration. But if you click on the start arrow, the phase and libration shifts to the first of the month. From there, it plays like a movie, with the terminator moving across the surface and the moon shifting to show the proper libration at each point. A clock at top shows the date and time for each frame in the animation.

At this point in the review process I ceased to be a lunar observer, and became a kid with a new toy. This has to be the coolest feature in any of the three programs! There in front of you sits the moon, rocking back and forth with the small libration changes caused by the observer' s movement as the earth rotates. And overall is the much larger movement of a month' s worth of libration changes, played out before you. It is fun to just sit and watch favorite craters move up into view and back towards the limb. Even more centrally located craters like Tycho, Plato or the larger Mare Crisium move in and out, changing in apparent shape as they go. I confess I played with this for a long time before moving on to checking out the other features!

Along with the libration movie and the libration data on the initial screen, there is a clear graph showing the direction and amount of libration for each day of the month. This can be presented for a geocentric position or your actual geographical location. Again, the small loops caused by the earth rotating the observer from horizon to horizon are superimposed on the larger monthly libration movements. Those wanting to observe features in the libration zones can quickly print out the libration results for the full month.

This brings up what I see as an underlying philosophical difference in the three packages. LMP basically presents what is present in a printed atlas, but at a smaller scale. There is no correction for libration. VMA takes this much farther, presenting the actual libration for the current moment. LPP does this as well, but also gives you additional tools and data for planning your observing sessions. All three give you a map, but LPP helps you plan out your observing sessions for the month.

This is illustrated by the second major feature I discovered (and the one that is rapidly becoming my favorite). Instead of simply listing lunar features, LPP presents them with the date and time for sunrise and sunset at each of those features. Printing this out is a big help for planning. For example, in writing this month' s LFM (on Tycho) I wanted to point out a swirl of craters that are near Tycho. They are only prominent for a few hours, when the terminator has passed them but not gone much farther. Looking up a crater that was where the terminator would be for best viewing of this cluster of craters, I checked LPP and found the date and time (my own local time) of sunrise for that crater. This was then included in the LFM article, as well as in my own observing session plans. In the same manner, if you wanted to observe or photograph Rupes Recta at sunrise, a quick check would tell you when sunrise will occur. I am presently printing out the sunrise and sunset data for all the listed features each month. It only takes a couple of pages but is very helpful! The accompanying visibility charts also help with planning by showing how high above the horizon the moon will be at those particular times of sunrise or sunset on the features I want to observe. Also listed are the moonrise, moonset and transit times for each day of the month in question. Once you go out to the scope, the Lunar Explorer Screen will come into play. This presents a map of the moon, corrected for libration. LPP and VMA have about the same level of detail. LMP has a slightly higher detail map, but it is much slower when panning or zooming. LPP is definitely faster than VMA and much faster than LMP.

The map and the ability to identify features works both directions. That is, you can click on a feature on the map, and LPP will give you the name and information about that feature. Or, you can go through a list of features and click on a name. The corresponding feature will then be highlighted on the map. Lists are broken down into 19 categories, including craters, maria, spacecraft landing sites, domes and rima. An additional category lists all of those items which are currently on the terminator.

Easily accessed buttons scroll the display to center the section you want to observe. A slider at the top will change the zoom so you can zoom in on a detail, or drop back to have the full moon in the display. Shortcut buttons will zoom to the 4 lunar quadrants and a North or South Pole view.

An additional feature is the map of the moon' s far side. LPP is the only one of the three to include this interesting (and fun!) ability. All of the features work on the far side so you can zoom in, pan, identify features etc. The map can also be flipped or inverted to show the view as it will appear in your scope. LPP and VLA both have this feature.

Virtual Moon Atlas is the latest product by Patrick Chevalley, the creator of Cartes du Ciel. It appears to use the same map scale as LPP. It does not include the many session planning tools of LPP but has some unique features of its own. Chief among these is the library of photographs. These can be called up for different lunar items you may be interested in. Many of these are Lunar Orbiter or Apollo photos, and all of the photographs are of high quality. Orbiter and Apollo photos have the disadvantage of being taken from a different angle than you are observing from --- features show their actual shape rather than the foreshortened view you have through the telescope. But their unsurpassed clarity and detail easily make up for this. There is also the ability to add your own photographs and link them to the program. VMA supplies more information on lunar features than does LPP. The description can be helpful, especially for those who are unfamiliar withthe item in question. The descriptions have apparently been translated from their original French, which occasionally gives unintended results. For example, Tycho is described as, Furnace of the most important radiating system,' rather than being the center of the largest system of rays. But overall, the translations are clear and concise.

The information also supplies the page number for Rukl, Hatfield, Westfall and Viscardy. Additionally, clicking on the Neighbors' button will give a list of lunar features that are neighbors with the item you are studying. Unlike LPP, the link between the lunar feature database and the map is only one way. That is, you can click on any feature on the map and it will be identified. But you cannot go to a list, select a crater or other feature and click to have it highlighted on the map. The only exception is features that are currently on the terminator. Features near the terminator can be selected from a list and they will become highlighted on the map. There is also a geologic map, dividing the surface into several different geologic categories. Unfortunately this is at a very rough scale and only of limited usefulness. It would be nice to see all three programs add higher resolution geologic maps in the future. One additional feature is the ability to measure distances. Using the Tools' section of the map you can mark points with the cursor and get the real distance between them. As with LPP, you can flip or invert the image to match the view at your telescope. This is especially helpful to those who have a hard time going from a correct' map to a flipped or inverted view at the telescope. The map view can be zoomed and panned.

Feature Comparison

Features are broken down into mapping and planning functions.

As you can see, both programs do a good job of mapping the moon. LPP simply adds more tools for planning your observing sessions.

As you may have noticed by now, I am impressed by both LPP and VMA, and less so by LMP. I am awarding an Author's choice to both programs but for different reasons.

VMA earns an award as it is very good mapping software at an outstanding price (free). Patrick Chevalley has developed both VMA and CdC as freeware to encourage amateur astronomers around the world. His vision and generosity are to be commended. And, even though it costs nothing, it is good software! I would encourage anyone who has a computer to download VMA and start there.

LPP is also an outstanding value. LPP goes beyond the mapping abilities of the other two and adds a great lineup of tools to plan your observing sessions (lunar feature sunrise/sunset times, visibility charts, libration charts), as well as the cool libration movie. The cost is only $40. You can also download a simpler version (Lunar Phase) as shareware ($30 registration and any registered LP user can later upgrade to LPP for $15). As helpful as VMA is, I think that most will find it worth the expense to purchase LPP and gain the planning tools.

LMP is the only nonwinner. But let me add that it is not bad software. Many will prefer it even with the higher price ($89.95). The map resolution is higher than either LPP or VMA. But it is the slowest of the three programs. Even more critical, the view is not corrected for libration. Yes, I know --- If you contact RITI they will explain that the terminator has been corrected for libration to make sure it is in the right place. But when I observe on the Lunar limb, I want to know what can and can' t be seen.

If I go to a map, I want it to match the view I have at that particular libration angle. If it doesn' t, I am ahead to stick with paper charts and maps. And, my own personal pet peeve is stupid copy-protection schemes. In the 1980' s, many software companies employed copy protection schemes. They are all inconvenient, and manufacturers slowly realized that people were simply not buying programs that required them to lug around their original disks. They were buying the competitors programs instead. RITI supplies a lengthy explanation that it is not because they don' t trust their customers but rather they must protect their investment. It is time to realize this is true for ALL software makers. And obviously they do not trust their customers because their customers are the only people they are selling this software to!

Costing more than twice as much as LPP, not correcting for libration, being the slowest of the three programs, and having a very inconvenient copy protection scheme put LMP in last place in this review. Still, others will not hesitate to spend the extra and will have all three programs installed. If money is very tight, I would definitely start with VMA. You can also download the simpler shareware version of Lunar Phase. Bear in mind that this is a simpler version and does not have all of the planning features of Lunar Phase Pro. I think you will find the additional features in LPP to be worth the $40 expense.