Best Examples of Studying Light Pollution Effects on Stargazing

Real-world examples of studying light pollution effects on stargazing

The best way to understand light pollution is to measure it directly. Instead of just saying “the stars look dimmer in the city,” you can design experiments that turn that observation into data. Below are several real examples of studying light pollution effects on stargazing that you can adapt or combine into a strong science fair project.

Each example of a project focuses on a simple question, repeatable measurements, and a clear way to show your results.

Example of a classic project: Counting stars in different locations

One of the most widely used examples of studying light pollution effects on stargazing is the classic star count project.

You pick a single constellation that’s visible from your location for several weeks (Orion, Cygnus, or the Big Dipper work well). On clear nights, you go to at least two different places:

• A bright urban or suburban area with lots of streetlights
• A darker location such as a park, rural area, or edge of town

At each site, you:

• Let your eyes adapt to the dark for about 15–20 minutes
• Look at the same constellation
• Count how many stars you can see within a defined area of the sky
• Record the date, time, approximate cloud cover, and location

Over multiple nights, patterns emerge. Typically, your star counts in the city will be dramatically lower than in darker areas. This kind of project is simple, but it’s one of the best examples of studying light pollution effects on stargazing with nothing more than your eyes and a notebook.

You can compare your results with citizen science campaigns like Globe at Night, which has been collecting star visibility data from volunteers worldwide for years: https://www.globeatnight.org

Examples of studying light pollution effects on stargazing with smartphone apps

If you want more quantitative data, smartphone apps can turn your project into a mini research study. Several apps estimate sky brightness or Bortle scale class (a standard scale astronomers use to describe sky darkness).

Here’s how a typical example of a smartphone-based project might work:

• You select 3–5 locations that range from very bright (downtown) to relatively dark (rural edge, nature preserve, or a state park if you have access).
• At each location, on multiple clear nights, you use a sky-quality or astronomy app to log a brightness value or estimated limiting magnitude (the faintest star visible to the naked eye).
• You also count how many stars you can see in a specific constellation or patch of sky, just like in the classic project.

Now you have two types of data: an app-based sky brightness reading and your own visual star counts. Strong projects don’t just show a single number; they compare data. You can graph sky brightness vs. visible star counts and show how even small increases in brightness wipe out a lot of faint stars.

This is one of the best examples of studying light pollution effects on stargazing for students who like tech and want their project to feel more like professional observational astronomy.

Using long-exposure photos as visual examples of light pollution

If you have access to a DSLR or mirrorless camera, you can create powerful visual examples of studying light pollution effects on stargazing.

You set up the camera on a tripod, point it at the same region of the sky from different locations, and take long-exposure images (for example, 10–20 seconds at the same ISO and aperture). Then you compare:

• How many stars appear in each image
• How bright the background sky looks (darker gray vs. bright orange or white)
• Whether you can see the Milky Way in the darker locations

Even without advanced image processing, you can:

• Count stars visible in each photo
• Use free software to measure the average brightness of the background

This gives you side-by-side visual proof. Two photos with identical camera settings but different locations become a striking example of how artificial lighting wipes out the night sky. For a science fair audience, this kind of before-and-after comparison is easy to understand at a glance.

Examples include comparing LED streetlights vs. older lighting

Since about 2015, many cities have been switching from older sodium-vapor streetlights to bright white LEDs. That shift is still happening in 2024–2025, and it creates a very current topic for your project.

You can design an example of a project around this question:

Do areas with newer LED streetlights have brighter night skies than areas with older, dimmer lighting?

To test it, you:

• Identify two neighborhoods: one with mostly LED streetlights, one with older amber or yellow lights
• Use your eyes, smartphone app, or camera to measure sky brightness and visible stars from both areas
• Try to keep other factors as similar as possible: same time of night, similar weather, similar distance from city center

You may find that LED-lit areas have higher sky brightness, even if the lights are more energy-efficient. That’s a great talking point: saving energy does not automatically mean saving the night sky.

For context and background on LED lighting and night sky brightness, the International Dark-Sky Association (IDA) is a solid resource: https://www.darksky.org

A time-based example: Tracking how sky brightness changes through the night

Light pollution isn’t constant. In many places, businesses close, traffic drops, and some lights turn off as the night goes on. That makes time a variable you can study.

In this example of studying light pollution effects on stargazing, you pick a single observing spot and measure sky conditions several times per night, such as:

• Just after astronomical twilight (when the sky is fully dark)
• Around midnight
• Early morning (2–4 a.m.)

At each time, you record:

• Star counts in a chosen constellation
• Sky brightness via app or camera
• Notes about nearby lighting (parking lots closed, house lights off, etc.)

When you graph your data, you might see that the sky gets darker after midnight, and more stars become visible. This is an excellent way to show that human activity directly shapes what we can see in the sky, hour by hour.

You can connect your findings to global trends. For example, satellite-based studies have found that Earth’s artificially lit outdoor area has been increasing over time. A widely cited paper in Science Advances reported persistent growth in outdoor artificial lighting from 2012–2016 using data from the VIIRS satellite sensor (see NOAA’s overview of night lights data: https://ngdc.noaa.gov/eog/viirs.html).

Mapping your neighborhood: A local light pollution survey

Another set of strong examples of studying light pollution effects on stargazing focuses on mapping instead of just single measurements.

You can turn your project into a mini light pollution survey of your town or school district:

• Choose 5–10 safe, accessible spots (home, school, park, parking lot, sports field, library, etc.).
• At each location on clear nights, measure sky brightness and star counts.
• Note major light sources nearby: gas stations, stadium lights, shopping centers, bright billboards.

Then you create a simple map (even hand-drawn or using a free mapping tool) showing each location’s brightness level. You might color-code locations from “darkest” to “brightest” and note how many stars were visible in each.

This kind of project is a great example of how studying light pollution effects on stargazing can turn into a local environmental investigation. It also opens the door to discussing potential solutions, such as shielding lights, lowering brightness, or using warmer-colored bulbs.

You can support your discussion with guidelines from the U.S. National Park Service’s Night Skies program, which studies and protects dark skies in national parks: https://www.nps.gov/subjects/nightskies/index.htm

Human eye comfort and stargazing: An often-overlooked example

Most projects focus on how many stars you can see, but there’s another angle: how comfortable is it to stargaze under different lighting conditions?

Here’s an example of a project that combines astronomy with human perception:

• Recruit a few volunteers (family or friends) to join you at two or three sites with different light levels.
• At each site, everyone rates:
  • How many stars they feel they can see (subjective estimate)
  • How comfortable their eyes feel after 10–15 minutes (for example, using a simple 1–5 scale)
  • How distracting nearby lights are
• You also collect your usual star counts and sky brightness measurements.

Then you compare subjective experience to objective data. Do people report more eye strain or distraction in brighter areas? Does their sense of “starry” skies match your actual star counts?

This project is a good example of studying light pollution effects on stargazing that goes beyond numbers and connects to human health and well-being. If you want to hint at broader impacts, you can mention that the American Medical Association has raised concerns about bright outdoor lighting at night affecting sleep and circadian rhythms (see AMA policy on LED street lighting: https://www.ama-assn.org/ for relevant reports).

Designing your own experiment: Turning examples into a science fair project

All of these examples of studying light pollution effects on stargazing share a common structure:

• A clear, testable question (for example, “How does sky brightness change between my school and a nearby park?”)
• A consistent method (same constellation, same exposure settings, same app, same time windows)
• Repeated measurements over several nights
• A way to compare locations, times, or lighting types

You can mix and match these real examples:

• Combine star counts with smartphone readings
• Add long-exposure photos as visual proof
• Track changes over time of night or over weeks
• Compare different types of streetlights or neighborhoods

When you write your report, make sure you:

• Explain what light pollution is and why it matters for astronomy
• Describe your methods clearly so someone else could repeat your work
• Present graphs or tables comparing your measurements
• Interpret what your data means for stargazing in your area

If you want more background on the science of light at night and its broader environmental impact, the International Dark-Sky Association has educational resources suitable for students: https://www.darksky.org/our-work/grassroots-advocacy/resources/

FAQ: Common questions about examples of studying light pollution effects on stargazing

Q: What are some easy examples of studying light pollution effects on stargazing for beginners?

A: The easiest starting point is a simple star count in one constellation from two locations: your home and a darker spot like a park. You only need your eyes, a printout or sketch of the constellation, and a notebook. If you want a small upgrade, add a free smartphone sky-brightness app so you can compare your star counts to a numerical brightness value.

Q: What is one example of a more advanced light pollution project for high school?

A: A strong high school-level example is a project that combines long-exposure photography, smartphone brightness readings, and star counts across several locations. You can analyze how sky brightness correlates with the number of visible stars and compare areas with different types of streetlighting. Adding a time-of-night component—measuring just after dark, at midnight, and before dawn—can raise the level of your project further.

Q: Do I need a telescope for these examples of studying light pollution effects on stargazing?

A: No. In fact, most of the best examples do not require a telescope at all. Light pollution affects naked-eye viewing first, so counting stars, measuring sky brightness, and taking wide-field photos of the sky are perfectly valid and scientifically interesting. If you do have a telescope, you can add a twist by noting which deep-sky objects (like certain galaxies or nebulae) are visible from dark vs. bright locations.

Q: How long should I collect data for a strong project on light pollution?

A: Aim for at least a couple of weeks of observations on multiple clear nights. The more data points you have, the easier it is to see real patterns instead of one-night flukes. Many of the real examples of studying light pollution effects on stargazing you’ll see in citizen science projects collect data across months or even years, but for a science fair, a 2–4 week window is usually realistic.

Q: Are there any safety tips I should follow while doing these projects at night?

A: Yes. Always observe from safe, legal locations. Bring an adult if you’re going out after dark, especially to parks or rural areas. Let someone know where you’re going and when you’ll be back, and carry a red-filtered flashlight so you can see your notes without ruining your night vision. Planning safety into your project is just as important as planning your data collection.

Light pollution may feel like an abstract environmental issue, but once you start measuring it, you see how directly it affects your own view of the universe. These real, practical examples of studying light pollution effects on stargazing give you everything you need to turn a washed-out sky into a sharp, data-rich science fair project.