Sentinel-2 is part of Copernicus, the European Union's Earth observation programme, and is operated by the European Space Agency. Where NASA's Landsat archive stretches back to 1972 with 30 metre pixels, Sentinel-2 is the newer, sharper companion: 10 metre pixels in visible light, and a five-day revisit cycle that catches the planet as it changes through the seasons.
The constellation is two satellites flying in the same orbit on opposite sides of the Earth, 180 degrees apart. Sentinel-2A launched on 23 June 2015. Sentinel-2B followed on 7 March 2017. Sentinel-2C launched on 5 September 2024 to extend the mission, with Sentinel-2D planned to keep the constellation running into the next decade.
What it actually does
Each Sentinel-2 satellite carries a single instrument: the MultiSpectral Imager, or MSI. It records 13 spectral bands at once, from visible blue at 443 nanometres through to shortwave infrared at 2190 nanometres. Four of those bands (blue, green, red, and near-infrared) are recorded at 10 metres per pixel. Six bands sit at 20 metres, covering the red edge and shortwave infrared where vegetation and water leave their clearest signatures. Three more bands are recorded at 60 metres and are used mainly for atmospheric correction.
The swath is 290 kilometres wide. The satellites orbit at 786 kilometres altitude in a sun-synchronous orbit, which means they cross every point on the ground at roughly the same local time of day, year after year. That consistency is what makes the imagery comparable: a field photographed in March 2018 can be set next to the same field in March 2026 and the light, the angle, and the geometry will match.
Why it matters
Sentinel-2 was built for the working business of looking after a planet: tracking how crops grow, watching forests for disease and clearance, mapping floods within hours of the water rising, monitoring algal blooms in lakes and along coasts, measuring how cities sprawl, charting glaciers as they retreat. The 10 metre detail is sharp enough to resolve individual fields, suburban streets, harbours, and reservoirs.
Like the Landsat archive, Sentinel-2 data is free. The Copernicus data policy is full, free, and open: anyone, anywhere, can download any scene without licence fees or registration walls. According to ESA, the Copernicus Data Space distributes around 930,000 products per month, totalling roughly 4 petabytes of imagery downloaded by users every month. That makes it one of the most heavily used scientific datasets on Earth.
The satellites
Sentinel-2A and Sentinel-2B were both launched from Europe's Spaceport in French Guiana on Vega rockets. They are physically identical, which is the point: by flying two of the same instrument on opposite sides of the planet, ESA halves the time between visits to any given patch of ground. A single satellite would revisit every 10 days. The pair, working together, brings that down to 5 days at the equator and closer to 2 or 3 days at mid-latitudes where their swaths overlap.
The programme is funded by the European Union and delivered by ESA, with the European Commission overseeing Copernicus as a whole. The data is distributed through the Copernicus Data Space Ecosystem and partner archives, and is used by farmers, foresters, insurers, emergency response teams, climate scientists, and Earth observation companies across Europe and beyond.
How it works with Landsat
Sentinel-2 and Landsat are complements, not competitors. Landsat has the longer memory: more than five decades of calibrated 30 metre imagery, the only continuous record of its kind. Sentinel-2 has the sharper eye and the faster cadence: 10 metre pixels and a fresh look every five days. Together they form a virtual constellation. A researcher tracking a forest or a coastline can chain Landsat scenes back to the 1980s and then continue the time series at higher resolution with Sentinel-2 from 2015 onwards.
For Your Name From Orbit, that combination matters. Some letter-shaped features in the world (a curve of coastline, a bend in a river, a field boundary) read more clearly at 10 metres than at 30. Others are large enough that Landsat catches them perfectly. Drawing from both archives means a wider palette of real places that happen to look like the letters of a name.
Sentinel-2 in the field
The five-day revisit cycle is not an abstraction. When something happens on Earth (a volcano opens a new vent, a river of lava reaches the sea, a forest catches fire) Sentinel-2 is usually overhead within days. Three recent events show what that looks like in practice.
La Palma, a river of lava reaches the sea
The Cumbre Vieja volcano on the Spanish island of La Palma began erupting on 19 September 2021. Sentinel-2 photographed the new lava flow on 10 October, using its shortwave infrared channel to pick out the hot rock against the cooled landscape. ESA noted lava temperatures of up to 1240°C, and that the flow destroyed the few remaining buildings still standing north of the Todoque neighbourhood. By 8 October the eruption had affected 497 hectares of land and destroyed over 1100 buildings, with the Copernicus Emergency Mapping Service releasing 17 monitoring products from the satellite data.
Source: ESA, La Palma volcano: How satellites help us monitor eruptions →
Mount Etna, Europe's largest active volcano
On 2 June 2025, a massive plume of ash, gas and rock burst from Mount Etna on Sicily, the largest eruption from the volcano since 2014. Sentinel-2 captured the moment on the same day, with the plume drifting from a partial collapse of the northern flank of the southeast crater. Tourists on the volcano were evacuated. Etna is Europe's largest active volcano, and the Copernicus archive holds repeat Sentinel-2 acquisitions of every paroxysm it has produced since 2015.
Source: ESA, Mount Etna erupts →
Iceland, the Little Ram opens up
Litli-Hrútur, which translates to "Little Ram", is part of the Fagradalsfjall volcanic area in southwest Iceland, the same system that returned to life in 2021 after nearly 800 years of dormancy. Sentinel-2 photographed the lava field and a long smoke plume drifting southwest on 26 July 2023. Eruptions here matter to far more than Icelanders: the prevailing wind pushes any plume toward European airspace, and the Copernicus archive provides the calibrated baseline that aviation authorities and atmospheric scientists rely on to model what is coming.
Source: ESA, Smoke plume from the Litli-Hrutur volcano →
Imagery: ESA, contains modified Copernicus Sentinel data. Skylit Studio is not affiliated with or endorsed by ESA, the European Commission, or the Copernicus programme.
