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Night-time light emissions during blackout in Spain and Portugal
Science & Exploration

Back to light

12/05/2025 4933 views 41 likes
ESA / Science & Exploration / Human and Robotic Exploration

As the night closed in on Spain and Portugal on 28 April, polar satellites followed the blackout that lasted well into the early hours of the morning in several regions.

While electricity was restored in most of the territory by evening, some areas remained in darkness longer.

Night-time images from NASA’s Suomi-NPP, NOAA-20 and NOAA-21 satellites captured the extent of the blackout and tracked the gradual electricity recovery from orbit.

Night-time light emissions during blackout in Spain and Portugal
Night-time light emissions during blackout in Spain and Portugal

The images show areas with both sustained power outages and restored light emissions during night-time.

Mapping a blackout in six frames

The three satellites circling Earth from pole to pole made six passes over Spain and Portugal between dusk and dawn. Each pass delivered a snapshot of the evolving power grid situation.

The six images illustrate the chronology and cartography of the blackout, from the first orbits at dusk to the near-complete recovery around 5 AM. It was a mostly cloudless night.

Green is black
Green is black

“By overlaying the six satellite passes and applying NASA’s night-time algorithms, we can identify large green spots suddenly appearing and gradually fading,” explains Alejandro Sánchez de Miguel, researcher at the Instituto de Astrofísica de Andalucía (IAA-CSIC) and project lead of several ESA-supported initiatives monitoring light pollution from space.

“The green dots indicate the absence of light, while white ones show areas with stable electricity supply. This distribution is consistent with electrical company reports and the gradual return to normality,” adds Alejandro.

Blackout in Andalusia
Blackout in Andalusia

This widespread power outage underscores how space-based monitoring tools can help assess infrastructure resilience, prioritise repairs and facilitate emergency responses.  

Scientific night shifts

Most Europeans live under light-polluted skies. The European Space Agency (ESA) coordinates and supports a scientific infrastructure that could turn power outages into case studies to investigate disruptions to the day-and-night rhythm of living organisms, including humans.

Iberian Peninsula at night
Iberian Peninsula at night

ESA contributes to the Night Watch project, a European multispectral mission studying nighttime light emissions. Cases like this blackout help establish thresholds for future monitoring systems.

For an astronaut looking out of the International Space Station windows, city lights are brighter than the stars. ESA astronauts also contribute images to several citizen science activities. The Cities at Night initiative calibrates, tags and geolocates the astronauts’ nighttime photography collection.  

The Rosetta and OSIRIS archive provides radiometric validation material for upcoming European night observation missions.

Useful links

-      Blackout visualisation app

-      Blackout in Andalusia, by NASA Earth Observatory.

-      ESA astronauts help map light pollution from space.

-      Lost at night project.