A satellite that can see through the tops of trees has just completed its first year in orbit, and the images it has sent back are unlike anything scientists have seen before. Launched on 29 April 2025 by the European Space Agency, the Biomass satellite carries the first spaceborne P-band synthetic aperture radar, a sensor powerful enough to pierce dense forest canopies and measure the wood hidden beneath,trunks, branches, and the carbon locked inside them.
How a radar satellite measures the weight of a forest
Biomass is an Earth Explorer mission, designed from the start to tackle one big question: how much carbon do the world’s forests actually hold? Until now, satellites could see the leafy surface of a forest, but not the woody structure underneath where most of the carbon is stored. Biomass changes that. Its P-band radar sends long-wavelength signals that pass through leaves and branches, bounce off trunks and larger limbs, and return to the satellite with data that scientists can convert into estimates of woody biomass,a direct proxy for carbon storage.
After launch, the mission team spent months calibrating the satellite during its commissioning phase. By January 2026, the data became openly available to users worldwide. Since then, the satellite has been delivering measurements that promise to sharpen estimates of forest carbon stocks and reveal how forests respond to drought, fire, and other environmental pressures.
From tropical jungles to Arctic ice
The images released to mark the anniversary show the satellite’s range. One captures the tangled waterways of the Mekong River in Cambodia. Another reveals the Beni River snaking through Bolivia’s lowland forests. There are views of the Amazon River in northern Brazil, the savanna landscape of Gulf Country in Australia, and a circular mountain plateau in Malaysia. The Berau River delta in Indonesia appears in vivid radar colour, as do thermokarst lakes in northern Siberia, crevasses in Antarctic ice, and the rugged river canyons of Russia’s Putorana Plateau.
These are polarimetric synthetic aperture radar images, meaning the colours do not match what a human eye would see. Instead, each colour represents a different structural property of the land surface,how rough it is, how wet, how the vegetation or ice is oriented. The result is a kind of x-ray vision for the planet.
Why local communities and scientists are paying attention
For people living in forest-rich regions like Brazil, Indonesia, and the Congo Basin, the mission has direct relevance. Better data on forest carbon means better monitoring of deforestation, reforestation, and the health of ecosystems that millions depend on. Brazil, in particular, has been preparing to harness Biomass data since late 2025, integrating it into national forest monitoring systems.
Beyond forests, the satellite has proven useful for measuring ice sheet velocities in Greenland and Antarctica, and for studying subsurface geology in arid regions. The same radar pulses that penetrate tree canopies can also probe dry sand and rock.
A year in, and the view is only getting clearer
The Biomass mission is still young. One year of data is enough to show its potential, but not yet enough to answer the big questions about global carbon stocks and how they are changing. The images released so far are a glimpse,a promise of what becomes possible when a satellite can see what has always been hidden. For scientists tracking the planet’s carbon cycle, that view is just beginning to come into focus.
