On 3 October, ESA’s European Space Astronomy Centre (ESAC), in Villanueva de la Cañada, opened its doors with a programme that invited visitors to explore black holes, exoplanets and the far reaches of the universe alongside its astronomers.
The Plan-B project, in which Ibercivis is part of the consortium, proposed an activity: placing on a map the night-time photos that astronauts take from the International Space Station, using the Lost at Night tool.
Visitors of all ages in front of the screens in the ESAC computer room.
The problem: beautiful photos that are not yet maps
Astronauts on the ISS have been photographing the Earth at night for more than twenty years. Many of these images already have an approximate location, but that is not enough to use them as scientific data. To do so, they have to be georeferenced: each photo must be aligned with its exact geographic coordinates, so that every pixel corresponds to a specific point on the planet.
That is what Lost at Night does: with the help of volunteers, it builds a global map of the Earth’s night-time lights in order to measure the impact of light pollution on ecosystems and human health. The project is funded by the European Union under the Horizon Europe programme (PLAN-B initiative).
How a photo is georeferenced
The task is simpler than it sounds. The screen is split in two: on the left, the night-time ISS photograph; on the right, a map. Volunteers look for recognisable features on both sides, such as a coastline, a motorway or a junction, and mark the same point on the photo and on the map. Each pair of points is called a control point. At least three are needed, and ideally seven well spread across the image. The system warps the photo to fit the map and lets you preview the result before submitting it.
The team on the day: three ASAAF volunteers, Celia Rubio Morales, Rocío Antón Freire and Víctor Pascual Pedrosa; Carlos Tapia Ayuga (AINIA); Verena Rodríguez González (ESAC), who coordinated the activity; and researcher Alejandro Sánchez de Miguel (right).
A full room all morning
The room was busy all morning. People of all ages sat down, and there were lots of children, who set about finding streets and coastlines with a fluency that more than one adult struggled to match. Between screens, we showed the project’s models and the app’s game.
We also handed out teaching units to the teachers who dropped by, along with a printed leaflet, made by Verena, who works at ESAC, explaining how to take part from the app.
There were six of us in total: three ASAAF volunteers, Carlos and Verena, who coordinated the activity. Thank you all for your effort on a long day.
What the data says
The numbers were encouraging. Open Day was the busiest day since September, with around 150 tasks completed in a single day, almost all by anonymous users, as expected at an event open to the public. In the days beforehand there was already an uptick, which we attribute in part to the training of the volunteers.
At the time of writing, the project has gathered more than 32,000 control points, 1,818 georeferenced photos and 4,237 of the 27,471 planned tasks, that is, 15.4%. There is still a lot to do.
Tasks completed per day (registered and anonymous) and cumulative total. The dashed line marks Open Day.
Now it’s your turn
You don’t need to be at ESAC to take part. Go to lostatnight.org, click on participate and you will be assigned a random photo. If you would like to see how it works first, there is a video tutorial and a manual. If you are a teacher and are interested in the teaching units, write to us and we will send them to you.
Thank you to ESAC for opening its doors to us, and to everyone who sat down for a while to put maps to the night as seen from space.