Marchena Island rises quietly from the Pacific, a remote and uninhabited part of the northern Galápagos. Despite its isolation, the island supports a surprising variety of wildlife, including Galapagos hawk (Buteo galapagoensis) and Nazca booby (Sula granti).
Covering about 130 square kilometres (50 mi2) and rising to 343 metres (1125 ft), Marchena is dominated by a broad shield volcano containing one of the largest calderas in the archipelago. Younger lava flows have partly filled its crater, forming a rugged terrain of black rock and ridges. Fur seals (Arctocephalus galapagoensis) gather in hidden coastal grottoes, while the rocky slopes are home to the endemic Marchena lava lizard (Microlophus habelii), found nowhere else on Earth.
The radar-based image, captured by the mission on 5 September 2025, provides a detailed view of the island’s volcanic landscape. This artistic impression of Marchena Island was created from Sentinel-1 radar data, with colours added to visualise surface structures (radar can detect textures and elevation changes that are invisible to the human eye).
Conservation work has helped protect this fragile ecosystem. Feral goats introduced decades ago were eradicated in the late 1970s, and the invasive little fire ant, first detected in 1988, remains under active control by park teams.
Marchena is part of the Galápagos National Park, created in 1959 to protect 97 percent of the islands’ land area. The Galápagos Islands are a UNESCO World Heritage Site, recognised for their extraordinary biodiversity – from giant tortoises and marine iguanas to the many species that inspired ’s theory of evolution.
Using C-band synthetic aperture radar, Copernicus Sentinel-1 can record surface details day or night and through cloud cover, allowing continuous monitoring of these volcanic islands and the delicate habitats they sustain.
Featured image credit: European Union, Copernicus Sentinel-1 imagery
