Twilight Times

Displays the Start and End times of Civil, Nautical and Astronomical twilight for your location. During the summer months, there is, usually, no astronomical twilight at all. The word None will appear in the Start and/or End time slot when this happens. The further North or South your location, the longer the Sun stays above the horizon during the Summer months and at extreme northern or southern locations, there may not be any Nautical or Civil twilight. In such cases, again None will appear for the appropriate Start and/or End twilight times. All times are in local time.

At bottom right of the screen is the calendar, showing the dates for the selected month and year. Days are arranged (e.g. Monday to Sunday) according to the value selected on the Configuration Screen.

			Clicking this icon will print out a calendar for the selected month and year. The printout includes a graphical representation of the moon's phase for each day in the month, the Sun's rise/transit/set (SR/ST/SS) times and the Moon's rise/transit/set (MR/MT/MS) times. An icon representing any major phases during the month will be printed in the appropriate date box along with the time when that phase occurs. The printout also shows the correct 'inverted' lunar phases for Southern hemisphere users.
			Set display as viewed through binoculars or the naked eye
			Set display as viewed through an astronomical telescope
			Set display as viewed through an astronomical telescope that uses a diagonal
			Call up the Tabular screen
			Display menu of online lunar sites
			Lets you change the time, reset the time to Now or synchronise your PC clock
			Displays a menu of report options
			Calls up the Lunar Explorer screen
			This icon only appears on the menu bar if there is a lunar eclipse during the selected month
			Link to the Night Sky Observer astronomy site
			Call up the Configuration screen
			Display LunarPhase Pro Help. This calls up the help file in the default web browser
			Display About window. Contains application version number, copyright and contact details
			Minimise LunarPhase Pro
			Exit LunarPhase Pro

Configuration Screen

This screen allows you to enter your latitude and longitude and the name of your location. Many locations can be entered and stored to let you switch between the specifics of different observing locations. The Timezone and Daylight Savings Time setting are stored along with the location information.

The first time you run LunarPhase Pro, you will need to update the "Home" location so LunarPhase Pro knows what latitude and longitude to base its calculations upon.

Four buttons allow you to add/edit/delete locations. Add adds whatever data is on screen as a new location, Update updates the existing location with the data onscreen, overwriting the previous data for that location. Delete permanently removes a location. Cancel resets everything to blanks and zeros.

You can change locations simply by selecting a different location from the dropdown box. The contents of this box are automatically updated whenever a new location is added or an existing location is deleted.

The screen also allows you to change the day order on the calendar, the date format for the Tabular screen and the lunar feature type that automatically appears when you access either the Features Rise/Set Times screen or the Features Database screen.

LunarPhase Pro can display graphics in three resolutions (low, medium and high) and the Configuration screen lets you define which resolution best suits your system. Current PCs should have no problem running LunarPhase Pro at the highest resolution. Older PCs might need to use the medium or low resolution mode as the high resolution maps use a fair amount of resources. When LunarPhase Pro starts for the first time, it defaults to using the lowest resolution graphics.

Also on this screen is an option to set the type of printer you have (Laser, B&W Inkjet or Colour Inkjet). This setting has nothing to do with the settings specified for your individual printer. Based on your choice here, LunarPhase Pro merely uses different colour or grey shade selections to achieve the best possible printout (shades of grey aren't nearly as appealing as colour on a colour printer).

Exit the screen by clicking the Exit icon. It is at this point that any changes you have made are committed. (Currently, there is no way of simply escaping from the screen).

Viewing Date Information

The Julian Day, Day Number, Week Number (and Day/Week numbers in ISO format) and the number of days till Christmas for any date on the calendar can be viewed by right-clicking on a date in the calendar. The equivalent date in the Moslem Calendar is also calculated and displayed on this screen. The information window will automatically close as soon as you do anything else within LunarPhase Pro. It can be also be moved, as with all other windows in the application, by clicking on the window title and dragging the window to the desired location.

Tabular List Screen

This screen lists the rise, set and transit times for both the Sun and the Moon, the illuminated fraction of the moon's disk, the Start and End times for Civil, Nautical and Astronomical twilight and the Local Sidereal Time at Midnight. All times are in local time. Data for every day in the selected month are displayed on the screen. The Print icon on this screen's menu bar prints out a copy of the data contained in the list.

LunarPhase Pro provides a number of links to online sites dedicated to the moon and lunar phenomena as well as to sites detailing previous and current lunar space missions. If anyone has suggestions for links they think would be useful, please email me at gnugent@indigo.ie

This screen displays additional lunar libration information for the selected month and is divided into three panes.

At the left of the screen is a diagram showing the moon's libration over the course of the month. The moon can tilt up to about 8 degrees in latitide or longitude as shown on the graph's axes. Two plots are possible, with either, both or none being selected via the two toolbar icons.

The default plot (big yellow dots with little orange dots between them) shows the moon's topocentric libration for the month [topocentric means as seen from your location as specified in Configuration the screen]. The plot tends to oscillate between daily positions.

The second plot available shows the moon's Geocentric libration (i.e. as it would be seen from the centre of the Earth), This plot is nade up of light blue dots connected by darker blue lines. It's a much smoother plot since it doesn't account for your changing position relative to the moon as each day wears on.

The second pane, at top right of the screen, displays the maximum and minimum librations for the selected month. This is the same information that's provided in the monthly sky notes section of some of the astronomy magazines. The data is presented in the standard format as an overall figure in a specific direction (e.g.: 6.5° in PA 275.1°).

The third icon on this screen's toolbar prints out the current diagram, along with the maximum and minimum geocentric librations for the selected month. The current moon diagram, with the yellow dot indicating the maximum libration point for the selected time and date is also included on the printout.

Called from the Reports menu, (), this displays the moon's visibility for each day in the month (the month that's selected on the main LunarPhase Pro window). The days are numbered down the side of the diagram.

This diagram is especially useful for getting an instant view of what nights in the month will be suitable for deep sky observing or lunar observing (depending on your preference). It also shows how the days lengthen or shorten over the course of the month.

The black area down the centre of the diagram represents night, the light blue areas, day. The three dark stripes of blue on either side of the diagram represent Civil (dark blue), Nautical (darker blue) and Astronomical (darkest blue) Twilight.

The moon is depicted by the cream coloured horizontal lines, the thickness of which indicates the phase of the moon (thick = full moon, no line = new moon). The lines only appear when the moon is above the horizon at your location.

The diagram defaults to the nighttime view where the single vertical line down the centre of the diagram represents midnight. The dates down the side of the diagram therefore start at this position rather than the left hand side of the diagram. So, day 1 comprises the right half of the line marked as '1' and the left half of the day marked as '2'. This may take a bit of getting used to, but just remember that each line on the diagram covers from midnight on one day to midnight on the next.

The diagram can also be switched into daytime mode by clicking on the () icon. The icon will change to (). In this mode, each line on the diagram also represents a day running from midnight to midnight, but each complete line now represents a single day. The line down the middle of the diagram represents mid-day in this mode. Clicking the () icon will return the diagram to nighttime mode.

The diagram is also capable of displaying an overlay grid with divisions for each hour in the day (labelled at the top of the diagram). The hour numbering will depend on whether daytime or nighttime view is in effect. The hour grid is there just to give some idea of when the sun rises/sets, twilight start and end times and moon rise/set times.

The diagram, as it appears on screen (in day/night mode, with or without grid) can also be printed out.

Icons

		Print Lunar Visibility Diagram
		Indicates diagram is in night-time mode. Click to switch diagram to day-time view
		Indicates diagram is in day-time mode. Click to switch diagram to night-time view
		Indicates no grid overlaid on diagram. Click to turn grid on
		Indicates grid overlays diagram. Click to turn grid off

This screen, which is also called from the Reports menu, (), displays the Moon's and Sun's visibility for the selected date - the times when it's locally above the horizon, it's elevation on an hourly basis and it's Azimuth.

The screen is broken into two panes. The top one presents the diagram and the bottom one displays the hourly time, altitude and azimuth data. At a glance, you can see when the Moon and Sun rise and set and whether they're in the sky at the same time or not. In addition, the Moon's phase for the selected date is displayed.

There are several items in the diagram. Down the left side is the angle of altitude/elevation, ranging from 0 degrees to 90 degrees. Across the bottom of the diagram are the hours of the day. The thick green line just above represents the horizon. The moon is plotted for every half hour on the day (00:30, 01:00, 01:30, etc.). The diagram gives a quick view of when the Moon ans Sun are highest in the sky and how high they get. There are also divisions marked on the diagram to show when the moon reaches the four cardinal compass directions (North, South, East and West) in Azimuth.

The actual figures for Azimuth and Altitude are listed in the lower window. These are displayed for hourly (rather than half-hourly) increments.

Whether or not the Moon icons are displayed on the diagram are controlled by the ( - Moon On) and ( - Moon Off) toolbar icons. Similarly, the Sun can be toggled on and off with the ( - Sun On) and ( - Sun Off) toolbar icons.

The diagram and data can be printed out as well.

Display Phases for Month

This screen is called from the Reports menu () and displays the moon's phase for each day in the month (the month that's selected on the main LunarPhase Pro window). The phases are displayed in a calendrical format, with each day being numbered.

The day order (Sunday-Saturday, etc.) depends on the current selection of the "Day Order" on the Configuration screen and can be changed as required.

The window provides an option to save the image as a .JPG graphic. A save dialog allowing you to specify a filename and directory path will appear. The save option is provided as a means of allowing you to use the image within your own web pages if you so wish.

Equinoxes and Solstices

LunarPhase Pro provides a menu of report options, one of which brings up a window displaying the times and dates of the Equinoxes and Solstices for the selected year. This window also lists the duration (in days) of each of the seasons.

Easter Sunday

Another option on the Reports menu () displays the date of Easter Sunday for the current year (as set on the main LunarPhase Pro window).

">

Double clicking any listed eclipse will call up the Eclipse Details window which will list all details for the selected eclipse. The time and date on the main LunarPhase Pro window will also be set to the (maximum) time and date of the selected eclipse.

The Moon's orbit is inclined at 5 degrees to the plane of the Earth's orbit around the Sun. A lunar eclipse occurs when the Earth moves between the Sun and the Moon such that the three bodies are in line and the Moon moves into the Earth's shadow. Lunar eclipses can only occur when the moon is near full and can be seen from anywhere on Earth where the moon is above the horizon. The Moon doesn't normally completely disappear since it is illuminated by light scattered from Earth's atmosphere, but it usually becomes a reddish, coppery colour.

The full shadow of the Earth, called the umbra, is surrounded by a partial shadow, called the penumbra. At the beginning and end stages of an eclipse, the Moon moves into the penumbra. This shadow is barely discernible on the lunar disk and eclipses where the Moon only passes through the Earth's penumbra are known as Penumbral Eclipses. There are two other types of eclipse: Partial where only a part of the moon passes though the Earth's umbral shadow and Umbral where the Moon is totally enveloped by the umbra. These eclipses are better known as Total Lunar Eclipses.

The Eclipse Details screen lists the times at which various events in an eclipse occur. The amount of information presented will depend on the type of eclipse, with total (umbral) eclipses having the most information. All times are presented in local time (not UT).

Below these times, for reference, are the times of moonrise, moonset and sunrise and sunset for the day in question.

This window also shows whether or not the eclipse is visible from your location.

The right half of the screen is taken up by the eclipse diagram. This shows the position of the moon in the umbra and/or penumbra at the time of maximum eclipse. The horizontal line represents the plane of the Earth's orbit and the slanted line, the path of the moon in it's orbit (going from left to right).

Sunrise/Sunset at Lunar Features

This screen displays a list of lunar features and the local times at which the Sun will rise and set at those features after the selected date. This is useful for observing specific lunar features where long shadows will give the greatest relief. It should be noted though that times are only approximate (actual sunrise or sunset will occur within a few minutes of the displayed times). It should also be noted that some features are very large and the leading and trailing edges of a Mare or large crater may be a couple of degrees away from the actual latitude/longitude as provided in the database. The rise/set times of such features will, therefore,be less accurate than those for small lunar features such as mountains or small craters. A database of 1,961 features (from the United States Geological Survey) is included with LunarPhase Pro. The features are broken down into 17 distinct types, each of which can be selected from the dropdown box. Calculation times for each type of feature will differ, depending on the number of features of that type. Craters outnumber everything else (there being over 1,500 of them in the database), so it will take several seconds for the calculations to be performed for these. Clicking the () icon brings up the Lunar Features Database list screen.

1,961 features are provided in the database, broken down into the following 17 types of features, which are selected from the dropdown box:

All the features included have been taken from the United States Geological Survey. It is the complete list as provided by the USGS, and includes features that are on the moon's far side. Any feature with a longitude greater than 90 degrees East or 90 degrees West is a far-side feature.

The data provided includes the feature name, its lunar Latitude and Longitude (near-side and far-side features), its diameter (in kilometres) and comments about the feature - typically who it's named after and a little bit about the person. The screen can be scrolled right and left to read long comments that don't fit within the screen border.

This screen allows you to explore the moon at your leisure. The screen is split into three panes. At left is the moon display. Three blue slider buttons lie at the top, right and bottom of this pane. The top button controls the amount of zoom for the map, the right slider button allows you to shift the map up and down and the bottom slider lets you move the map right or left.

At top right is a small panel providing quick access to various views of the moon - All Quadrants (a full view of the moon), then the North-East, North-West, South-East and South-West quadrant views (which show more detail) and finally, but only if the OpenGL option is turned on, the North and South Pole views.

Below this, the third pane displays lists of lunar features or specific feature information, depending on what your doing on this screen.

Terminator Features

When this screen is initially displayed, it defaults to displaying a list of the lunar features that currently lie along the moon's terminator. Clicking on any of the features listed will identify it on the moon map. The selected feature will be outlined by in yellow. You may need to scroll the map using the left-right and up-down sliders to bring the feature into view.

Listed alongside the feature names are the feature's lunar latitude, lunar longitude, the size of the feature and any comments about that feature. Simply scroll the display to the right or left to access this information. All this information is also available for viewing in the Lunar Features Database.

Feature Identification - Feature on List

The heading (on startup: "Terminator Features") for the third pane is, in fact, a drop down menu. Click on the down arrow to call up the list of options available. These are lunar features broken down into 17 distinct feature types, such as Craters, Mare, Sinus, etc.

Selecting one of the options loads a list of that type of feature into the third pane. Where a feature type contains a large number of items (such as Creaters), you can use the scroll bar at the right of this pane to move through the feature list. Scrolling left/right reveals more information about that feature.

As with the Terminator Features, clicking any of the features in the list highlights that feature in yellow on the lunar map.

Feature Identification - Feature on Map

Besides identifying features from a list, LunarPhase Pro allows you to identify features by clicking on them on the lunar map.

When you move the mouse cursor over the moon map, it changes to a cross-hairs in a circle. As you move the cursor, the second pane displays the location of the cursor in latitude and longitude (on the moon). Move the cursor over a feature and click the left mouse button. If the feature is in the database, information about it will be displayed in the third pane (replacing any list that was already there).

In addition, the times of sunrise and sunset at that feature are also displayed.

Whatever the view of the moon in the moon-display pane (i.e. regardless of zoom factor, left-right or up-down settings of the sliders) features can be identified with a simple mouse click.

Grid Overlay

To the left of the window's title are two extra toolbar icons. The leftmost will toggle an overlay longitude and latitude grid on and off. The grid will appear on both the spherical projection and mercator projection maps. The lines are 10 degrees apart and are labelled along the central vertical and horizontal axes.

Printing Maps

The second toolbar icon to the right of the window title prints out the map currently in the main moon display pane. If the longitude and latitude grid is turned on, then the grid will also be included on the printout.

The best quality maps will be produced when the the highest resolution has been selected on the Configuration screen and the mercator map projection is used. The Spherical projection maps will print out but will be at a lower resolution than the equivalent mercator projection maps.

The OpenGL Option is Turned On

If you have the OpenGL option turned on (on the Configuration screen) then, when this screen starts up, the moon is displayed for the selected time and date (as set on the main LunarPhase Pro screen). The moon will show the correct phase and includes all libration variations in its presentation.

The toolbar presents six icons. First, there is the icon to switch the moon map display between the 3D spherical view (the moon as you'd see it) and the 2D flat Mercator projection map of the moon.

The second icon allows you to switch between views of the moon's Near side (the side we see) and the moon's Far side (the side we never get to see). If the 3D view is enabled, then the moon's phase on the far side will also be shown. Libration is also catered for in the 3D far side view. Feature identification (by clicking on a feature on either map view) will also work on far-side features. Far-side features selected from one of the feature lists in the third pane will also be highlighted in yellow on the far-side map.

The third icon is primarily for Southern Hemisphere observers. This toggles the moon between the Northern Hemisphere view and the Southern Hemisphere view of the moon. It is automatically set on startup based on the user's latitude.

The fourth icon allows you to toggle the lunar terminator on or off.

The fifth icon calls up the Lunar Libration screen.

The sixth and final icon allows you to animate the lunar libration over the course of the selected month, showing lust how much the moon wobbles over the course of time. If you's rather run the animation without the lunar terminator, simply click the fourth icon to turn the terminator off. The animation will be stopped when the 1st of the following month is reached on the date /time banner or when you exit from the screen. The animation icon is disabled if either the North or South Pole view has been selected.

The option to view the moon's North or South Poles is available. Once again, features can be identified by moving the mouse cursor over them and clicking the mouse. These pole views allow you to get a better perspective on what very northerly or southerly features look like.

The OpenGL Option is Turned Off

If the OpenGL option is turned off, then you'll see a Mercator projection map of the moon on the screen. This map does not display the lunar terminator. Nor does it display any lunar libration.

The toolbar presents six icons. The first icon will do nothing if the OpenGL option is turned off. The only map format available for display is the 2D Mercator projection.

The second icon allows you to switch between views of the moon's Near side (the side we see) and the moon's Far side (the side we never get to see). Feature identification (by clicking on a feature on either near- or far-side map view) will also work on far-side features. Far-side features selected from one of the feature lists in the third pane will also be highlighted in yellow on the far-side map.

The third icon is primarily for Southern Hemisphere observers. This toggles the moon between the Northern Hemisphere view and the Southern Hemisphere view of the moon. It is automatically set on startup based on the user's latitude.

The fourth icon which toggles the lunar terminator on or off has no effect on the 2D Mercator Projection map.

The fifth icon calls up the Lunar Libration screen.

The sixth and final icon is disabled in the 2D Mercator Projection view (i.e. you cannot view an animation of the moon's libration for the selected month).

Contacting the Author

The author welcomes comments or suggestions on LunarPhase Pro (and reports of any bugs you might find) and can be contacted via his web page:

Night Sky Observer

or directly at: gnugent@indigo.ie

You can always news about LunarPhase Pro at the LunarPhaseCD Page