Eclipse Explorer Manual

Eclipse Explorer

User Manual

Eclipse Explorer App in Map mode with circumstances shown.

Warning!!! Never look at the Sun, eclipsed or not, without proper and certified eye protection. Looking at the Sun without such protection will result in permanent eye damage and possible blindness. 100% UVA/UVB sunglasses do NOT provide eye protection for looking at the Sun.

What's New!
Eclipse Explorer mobile now has audio event cues, please read more about them here:  Eclipse on Cue

Introduction

The Eclipse Explorer mobile application allows you to use your mobile device as a powerful solar eclipse circumstance computer. Using your device's GPS coordinates, solar eclipse circumstance information (time, date, type, and coverage) can be derived for your location.

Disclaimer
This program is provided “As-Is”. Use at your own risk. No warranty is expressed or implied. Data calculations and accuracy are never guaranteed. Data connection charges may apply. Not responsible for any data charges incurred at any time. Heavy data usage and/or high battery drain is possible while using this application. Not responsible for device failure while using this application. NEVER look at the Sun, at any time, without proper and certified eye protection.

Required Permissions

This application will require the following permissions:

Internet Access

For downloading and displaying maps, along with approximate position information.

Your Location: Coarse and Fine

Uses your device's IP address and / or GPS to derive your location. Used to make accurate astronomical calculations for your exact position.

App Header 

The application header will display the currently selected eclipse, the GMT date of mid eclipse, and the type of eclipse to occur. The app defaults to display the next solar eclipse to occur on Earth. This does not necessarily mean the eclipse will be visible from your location.

Lower Toolbar Display

Location Icon:

Indicates and controls GPS or manually derived location. 

Indicates automatic / GPS derived location.

Indicates manually selected location.


Lat:

Displays your current GPS derived latitude, or if in manual location mode, the selected latitude.

Long:

Displays your current GPS derived longitude, or if in manual location mode, the selected longitude.

Alt:

Your current elevation in feet. This is either derived from the device's internal GPS, or set to zero if GPS data is unavailable.

Time:

This is the current time for your current or selected position and is displayed in the local time zone. If highlighted in yellow, Time Travel Mode is active.

NOTE: Please keep in mind this time may be different from where you are, if you have manually selected a location in a different time zone from your current location.

Navigation Tab Bar

To navigate to various sections of the app, simply touch or swipe to display the following functions:

Circumstances

Displays eclipse event times and circumstances.

The Eclipse Map

Shows the eclipse area of visibility and Moon's shadow.

Simulation

Simulate the view of the Sun and the Moon from your current or selected location during the time of the eclipse.

Navigation Drawer

Press the menu button or swipe from the left to open the navigation drawer:

Eclipse Catalog

Displays a list of all eclipses from 1900 to 2100. Scroll through and select desired eclipse. The app will default to the next solar eclipse to occur on Earth. The currently selected eclipse will be highlighted.

Next Button

Will select the next eclipse to occur on Earth. This eclipse may not be visible for your current location.

Visible Button

Will select the next eclipse to occur that will be visible from your location (GPS or manually derived).

Eye Icon

Will display next to each eclipse that is visible from the current location (GPS or manually derived). As your location changes these icons will update automatically.

Audio Cues
This turn the audio cues on and off. Defaults to on.  When turned back on, a three beep cue will play for app audio awareness.  Read more here.

Circumstances

Here you can see key solar eclipse event times and circumstance data. All times are given in the local timezone of the GPS or manually derived location. The application uses your location information to calculate when the eclipse will occur for your specific location, so as you move, the eclipse times and statistics will change. If you have manually selected your location, event times will be given for that selected location's timezone.

Header

Dependent on your location you will see “No Eclipse Occurs”, “Partial Eclipse Occurs”, “Annular Eclipse Occurs” or “Total Eclipse Occurs”. If an eclipse does not occur for your location no further information is given.

Statistics

Coverage

The percentage of the Sun's disc covered by the Moon at the eclipse mid point for your specific location.

Magnitude

The percentage of the Sun's diameter covered by the Moon at the eclipse mid point for your specific location.

Depth

If a total or annular eclipse will occur at your location a depth indication will be given. This number denotes your relative distance from the exact center-line of the Moon's (ant)umbral path. The closer the number to 100%, the closer you are the eclipse center-line. An 'S' indicates you are south of the center-line and an 'N' indicates you are north of the center-line.

Events

Local Sunrise

The time the Sun will rise on the day of the selected eclipse for your specific location.

Partial Eclipse Begins

Astronomically referred to as “first contact”. This is the time the Moon will first start to cross in front of the Sun.

Total / Annular Eclipse Begins (Only displayed if this occurs)
Astronomically referred to as “second contact”. For a total eclipse, totality has begun at this moment and the Sun is completely covered by the Moon. For an annular eclipse, annularity has begun and the Moon is now just completely inside the Sun's limb.

Mid Eclipse At

This is the point in time in which the Moon has covered the largest portion of the Sun for your specific location. Up until this time, the Moon has been moving to “cover” the disc of the Sun. After this time, the Moon will begin to “retreat” from the disc of the Sun.

Total / Annular Eclipse Ends (Only displayed if this occurs)
Astronomically referred to as “third contact”. For a total eclipse, totality now ends and the Sun begins to reappear from behind the Moon. For an annular eclipse, annularity now ends and the Moon exits from inside the limb of the Sun.

Partial Eclipse Ends

Astronomically referred to has “fourth contact”. This is the moment in time the Moon leaves the disc of the Sun and the solar eclipse ends for your specific location.

Local Sunset

The time the Sun will set on the day of the selected eclipse for your specific location.

Countdowns

Each event has a countdown clock. The countdowns are formatted as such: DD:HH:MM:SS or Days:Hours:Minutes:Seconds. The number will be negative until the event has occurred, then it will be positive.

Example: -61:12:13:15 equates to 61 days, 12 hours, 13 minutes, and 15 seconds until that event occurs.

Duration

When listed next to “Partial Phase Begins”, this is the total duration of the selected eclipse at your specific location.

Example: 02:31:09 means the eclipse will last for a total of 2 hours, 31 minutes, and 9 seconds

When listed next to “Total /Annular Eclipse Begins”, this is the length of totality or annularity at your specific location.

Example: 02:17 indicates totality or annularity will last for 2 minutes and 17 seconds.

Below Horizon
Depending on your location you may see the “Below Horizon Icon” for certain eclipse events. This means that particular event occurs before sunrise or after sunset. Refer to the local sunrise and sunset times.

Example: If the “Below Horizon Icon” appears next to “Partial Eclipse Ends”, this indicates the Sun and Moon will set together before the eclipse ends for your specific location.

Eclipse Map

This section of the app allows you to view where the solar eclipse will be seen on Earth, animate the Moon's shadow, and plot the Moon's shadow in real-time. With an active internet connection, a very detailed map is displayed. When no internet connection is available, the app enters an “offline” mode and a less detailed map is available.

Map Controls

+ / -

The plus and minus buttons in the upper left corner will zoom in and out. You may also two finger pinch to zoom out and two finger spread to zoom in.

Sticky Button

When the sticky button is active (filled center circle) the map will automatically center on your current GPS position or manually selected location. To freely move the map, click the sticky button. To recenter on location, click the sticky button again.

Manual Location

Press the location mode icon so that is displayed, then touch a desired location on the map to change the app’s location. Manual location is also selected when searching for a location from the location search bar.

Map Online Refresh 

When in “offline” map mode, you may press this button to attempt to return to an online / detailed map.

Fullscreen Mode

Simply long press anywhere on the map to put the map in full screen mode. Long press again anywhere on the map to exit full screen mode.

Map Search Bar

Press the search icon to open a search box. Type in a city, address, or feature to set desired location in manual mode. A drop down of selections will pre-fill as you start to type. Touch the desired location to select a location in manual mode. (Only available with an active internet connection).

Map Overflow Menu

Touch the Map Overflow Button in the upper right corner of the Eclipse Map to open the map overflow menu.

3D Globe (Experimental)

Displays the map as a 3D globe. This function is considered experimental with bugs and heavy CPU/GPU usage.

Animate Shadow

Select to animate the motion of the Moon's shadow across the Earth on the day of the eclipse. You will see the shadow move and change shape as the Moon crosses between the Earth and the Sun.

NOTE: Because this function is computationally intensive it may take a while before you see the animation. Remain patient and remember the shadow generally moves from west to east.

Stop Animation

When the animation is active, select “Stop Animation” to stop. The Sun and Moon will return to their default positions during the midpoint of the eclipse at your location.

Realtime Shadow

This function will display the current location of the Moon's shadow on the day of the eclipse. The shadow will move in real-time across the Earth as the eclipse progresses. This function is only available when the eclipse is occurring or by using the Time Travel function.

Show Circumstances

When selected you will see the map, eclipse circumstances, and the Sun and Moon simulation all-at-once. All the functionality of the circumstances display (countdowns and time travel) is available. The Sun and Moon simulation will display in the upper right corner. The Moon will move across the Sun in realtime and animation mode, otherwise the midpoint view of the eclipse is shown for your selected location.

NOTE: This mode is recommended for large screen devices such as tablets.

Eclipse Area of Visibility

The larger area marked by red lines indicates the part of Earth that will experience at least a partial eclipse. If a total or annular eclipse occurs, a smaller path marked by black lines indicates where a total or annular eclipse will be visible.

Simulation

By computing the position of the Sun and the Moon in the sky, the app will simulate a view of the eclipse from your location. A yellow Sun will be centered on your screen overlaid by a black Moon. The simulation defaults to your view during the midpoint of the eclipse at your location.

Simulation Overflow Menu

Touch the Simulation Overflow Button in the upper right corner of the Eclipse Simulation to open the simulation overflow menu.

Animate Shadow

Select “Animate Shadow” from the overflow menu in the upper right corner to view an animation of the Moon’s path during the selected eclipse from your specific location.

NOTE: Currently this function is an estimate of the Sun and Moon's position. Differences between what happens in the actual eclipse and what the simulation shows may be seen. Further updates may refine the simulation.

Stop Animation

When the animation is active, select “Stop Animation” to stop. The Sun and Moon will return to their default positions during the midpoint of the eclipse at your location.

Realtime Shadow

This will position the Sun and Moon in their current (real-time) locations on the day of the eclipse. This function is only available when the eclipse is occurring or by using the Time Travel function.

First Contact

This will simulate the position of the Sun and Moon when the eclipse first starts or First Contact.

Second Contact (Only displayed if this occurs)

This will simulate the position of the Sun and Moon when totality or annularity first starts or Second Contact.

Mid Eclipse (Default View)

This will simulate the position of the Sun and Moon during the maximum part of the eclipse or Mid Eclipse. The Moon will be most “centered” or cover the maximum amount of the Sun's disc at this time.

Thirs Contact (Only displayed if this occurs)

This will simulate the position of the Sun and Moon when totality or annularity ends or Third Contact.

Fourth Contact

This will simulate the position of the Sun and Moon when the eclipse ends or Fourth Contact.

Time Travel

You may use the time travel function to see the location and movement of the Moon's shadow at different times during the eclipse.

To initiate time travel: Navigate to the Circumstances display or display circumstances in the Map. From here you may long press any eclipse event. The app will navigate to the map display and change the clock to 10 seconds prior to the selected event. If the eclipse is occurring at this time, the map will draw the Moon's shadow. You may view the map and simulation displays and watch as the eclipse progresses. The clock in the lower right corner will turn yellow to indicate that you are in “Time Travel” mode.

NOTE: The Moon's shadow may not be in your specific area at that selected time, zoom out to find it.

Time Travel Reset

To reset to the current date and time, simply press the clock in the lower right corner of the screen and the date and time will be set back to the present.

Known Issues
The Eclipse Explorer application is a work in progress. Currently the following are known issues to be fixed in a later version. Other bugs may occur.

• Hybrid eclipse shadows do not properly phase from annular to total. 
• Hybrid eclipse central lines may not show up correctly throughout their full length. 
• Some eclipses that occur very near the poles of the earth will not display at all on the map.
• Simulation of eclipse not yet accurate enough. (But it is getting very close). 
• Lunar limb corrections not yet accounted for. 
• Atmospheric refraction not yet accounted for.
• Timezone reverts to UTC in some oceanic areas.

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