Google Earth Pro includes a useful Sunlight tool that lets you see how sunlight and shadows appear across the landscape at different times of day. It is particularly useful when you want to visually examine terrain, buildings, hillsides, and other features under changing lighting conditions.
Unlike Historical Imagery, which changes the imagery date, the Sunlight feature changes the simulated position of the sun and displays its effect across the 3D landscape. Google explains that the feature can also be animated using the time slider.
Learn how to change coordinates from Decimal Degrees to Degrees Minutes Seconds in Google Earth Pro for accurate location and mapping workflows.
What Is the Sunlight Tool in Google Earth Pro?
The Sunlight tool allows you to examine the effect of sunlight across the Google Earth landscape. After activating it, a time slider appears, allowing you to move through different times and observe changes in illumination and shadows.
The feature can be especially interesting in areas with hills or mountains because changes in the sun's position can make slopes and terrain features easier to distinguish.
It is important to understand that the Sunlight tool is different from Historical Imagery. Historical Imagery changes the underlying satellite or aerial image to an available image from another date, while Sunlight changes the simulated lighting conditions.
How to Turn On the Sunlight Tool
Before starting, open the desktop version of Google Earth Pro and navigate to the location you want to examine.
Follow these steps:
Open Google Earth Pro.
Search for your location using the search box.
Position the 3D viewer so that the area you want to study is clearly visible.
Click the Sunlight button on the toolbar.
A time slider will appear.
Move the slider left or right to change the simulated time of day.
Watch how the illumination and shadows change across the landscape.
Click the play button on the time slider if you want to animate the changing sunlight.
Click the Sunlight button again when you want to turn the feature off.
Google's official help documentation confirms that activating Sunlight displays the current level of sunlight and brings up the time slider. The slider can be moved to explore sunrise and sunset conditions, depending on the location and time of year.
How to Control the Time of Day
Once the Sunlight feature is active, the time slider becomes the main control for exploring changing illumination.
Try moving gradually through the available times instead of dragging the slider quickly. This makes it easier to observe:
The direction of shadows
Areas receiving direct sunlight
Areas becoming shaded
Changes in the appearance of hills and slopes
How buildings interact with sunlight
Sunrise and sunset conditions
You can also use the play control to animate the sunlight across the landscape. This can be useful when you want to see the overall progression rather than inspect only one particular time.
Using Sunlight for Site Analysis
The Sunlight tool can provide useful visual information during an initial site assessment.
1. Examining buildings and shadows
If a location contains 3D buildings, changing the simulated time can help you visually examine how shadows extend from structures.
For example, you could compare a building's surroundings during morning and afternoon conditions. This can help you understand which areas appear more exposed or shaded.
However, treat the result as a visual assessment, not a substitute for detailed architectural or solar modelling.
2. Studying mountainous terrain
Sunlight can be particularly useful when viewing hilly or mountainous areas. Changing the simulated lighting can make differences between illuminated and shaded slopes more apparent.
This can help when visually interpreting terrain before carrying out more detailed GIS analysis.
3. Comparing different times of day
Hypothetical example: Suppose you are examining a proposed development site. You could activate Sunlight and compare several points during the morning, around midday, and later in the afternoon.
Instead of relying on one screenshot, record observations at consistent viewing angles and times. This makes your comparison easier to interpret.
Sunlight Tool vs Historical Imagery
These two Google Earth Pro features are easy to confuse.
| Feature | What it changes |
|---|---|
| Sunlight | Simulated lighting and shadows |
| Historical Imagery | Available aerial/satellite imagery from different dates |
Historical imagery is controlled through its own timeline, while the Sunlight feature uses the time slider to show changing sunlight conditions. Google notes that imagery in Earth is not real-time and may represent images collected on different dates or date ranges.
Important Limitations
The Sunlight tool is valuable for visualisation, but it should not be treated as a precision engineering or solar-design instrument.
Google Earth does not provide a built-in tool that directly reports exact shadow length or direction as an engineering measurement. A Google Earth Product Expert has also described the Sun tool as useful for visualising and approximating shadows rather than providing precise shadow calculations.
Other limitations include:
Google Earth imagery is not live.
Imagery may represent different acquisition dates or date ranges.
3D imagery can be created from aerial imagery collected over multiple dates.
The displayed imagery date does not necessarily mean that every visible feature was captured at exactly that time.
For detailed solar studies, architectural shadow analysis, or engineering decisions, use appropriate specialised software and site-specific data.
Common Mistakes to Avoid
One common mistake is assuming that the Sunlight slider changes the satellite image itself. It does not. The feature is intended to show the effect of sunlight across the landscape.
Another mistake is confusing the Sunlight slider with the Historical Imagery timeline. Both features use a time slider, but they perform different functions.
Finally, avoid treating Google Earth's visual shadows as exact measurements. Use the feature for exploration and preliminary assessment, then use appropriate technical methods when precise results are required.
For official instructions, readers can consult Google's Google Earth Help: View a map over time, which explains the Sunlight feature and its time slider
Conclusion
The Google Earth Pro Sunlight Tool is a simple but useful feature for exploring how simulated sunlight changes the appearance of terrain and shadows throughout the day. By activating Sunlight and moving the time slider, you can compare different lighting conditions and visually examine buildings, slopes, and other landscape features.
For GIS and site-analysis workflows, it can be a useful first step for understanding a location. However, remember that Google Earth is primarily a visualisation platform, so detailed engineering, architectural, or solar decisions should be supported by more specialised analysis and reliable site data.
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