Methane is a potent greenhouse gas, and major leaks from human activities, such as fossil fuel production, have significant climate impacts. Satellites offer a promising way to detect and measure emissions globally, but their performance must be tested under controlled conditions. To support this, we conducted the largest controlled methane release experiment to date.

From January to June 2025, we carried out 251 controlled methane releases at an Arizona test site. Each release simulated a real-world leak—like an unlit flare or venting event—and was timed with overpasses from 12 different satellites operated by government, commercial, and nonprofit organizations.

We precisely measured the amount of methane released, alongside detailed weather data including wind speed and cloud cover. These measurements provide essential reference data for validating satellite performance.

So far, 14 analysis teams from 9 countries have submitted over 800 results across the study’s first two phases. Roughly 75% of responses correctly detected the presence or absence of methane, showing strong detection capabilities. However, release rate estimates varied widely across teams and instruments.

These results highlight where current detection and quantification methods perform well and where improvements are needed. A third phase is underway through October 2025 to further evaluate these technologies.