The European Space Agency (ESA) reacted promptly to the discovery of comet 3I/ATLAS on 1 July 2025. Soon after they were alerted to its existence by automated detection systems, ESA astronomers began using ground-based telescopes in Hawaii, Chile, and Australia to monitor its progress.

Since then, the comet has been observed by space telescopes close to Earth, including the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webb Space Telescope.

In the coming months, ESA will turn interplanetary voyagers such as Mars Express, ExoMars Trace Gas Orbiter and the Jupiter Icy Moons Explorer (Juice) in the direction of the comet to make further observations from excellent vantage points.

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