The Loss of the Night app turns your eyes into a light meter, allowing you to become a citizen scientist and report how bright the night sky is where you live

Source: iOS description / Image:

Useful information

Download: Android 4.0 (3.99MB) / iOS  7.0 (14.2MB)

Price: free

Language: English / Arabic / Catalan / Czech / French / German / Hebrew / Italian / Japanese / Polish / Romanian / Chinese / Slovak / Spanish / Turkish

Runs offline: partially

Last update: Android 05/12/2016 (v. 2.1.7) – iOS 01/03/2016 (v. 1.2.1)

Website of the developer: Interactive Scape

Notes: article updated on 04/02/2017


Loss of the night is an application of citizen science that seeks to measure light pollution of the environment through the identification of a number of stars. As they explain in the blog of the project, the goal is to track the sky brightness in urban areas throughout the decades. It is a tool awarded in the first round of the challenge MYGEOSS 2015, whose winners were known on March 2015 (the winners of the second round were detailed in Greenapps&web – Spanish), being also included among the initiatives of light pollution included in the European project Starts4All.

The application works as follows:

  • Once installed, the app will ask you permission to transmit your location, since being a research project that collects environmental data, it is necessary to know where the application users are. Also, in a following screen, you will see that you can register as a user. This option allows you to specify your age and visual ability (if you wear glasses, contact lenses, etc.), two variables that are important in collecting data of this kind. Data collected by registered users is, therefore, considered to have greater value.
  • After filling these requirements, you access the main menu that has several options:
    • Project information, with access to documentation and tips to observe the sky.
    • User data, where you can consult your observations and config your profile.
    • Tutorial, that helps you know how the application works.
    • Start observing the stars, section from which you access to the observation map and identification of the stars.
    • News, section that contains news related with the application and the project.
    • Submit data from SQM or Sky Quality Meter, an instrument used by by amateur astronomers to quantify the sky glow.
    • Night mode, that which facilitates night vision
    • Feedback, to give your opinion about the app
    • Quit
  • The search of the stars is done following the indications of the pointer that appears on the screen. It’s recommendable also to let yourself be guided by nearby stars that are part of the constellations. You must be able to locate the requested star in the center of the displayed circle. Obviously, measurements should be done outdoors, in a moonless night and with few clouds or clear (be careful to not expose yourself to other hazards such as falls).
  • Once located the star, you must choose between one of the options shown at the bottom of the screen and select the correct option from the list that appears.

More information

Images: Screenshots 18/07/2016. © Interactive Scape



Light pollution is an unknown environmental problem for much of society. The emission of excessive artificial light, especially in urban areas, is related to alterations in circadian rhythms and the production of melatonin, the hormone that, among other things regulates the cycle of sleep and wakefulness. It also causes a clear impact on other living beings such as marine animals, although their exact effects are unknown, and the terrestrial wildlife, altering their habits. One of the latest discoveries even links this type of pollution with an earlier budburst of some tree species.

Loss of the night tries to deepen the knowledge about the impact that causes this type of pollution through citizen science, allowing application users to immerse themselves in the search for different stars, increasing also their knowledge on astronomy. It is particularly interesting to check the map that collects the different measurements (data from other similar projects are also dumped in this map ), being able to see the areas in which is easier to see the stars (very useful for amateur astronomers, astrophotography or other activities related with stargazing) or make comparisons with their own measurements (it would be appropriate to include some kind of explanation that would allow a correct interpretation of the data).

User Review
0 (0 votes)
(Visited 370 times, 1 visits today)

Técnico de medio ambiente, community manager y content curator especializada en temas de medioambiente - Environmental technician, community manager and content curator specialised in environmental issues