One early sign of the mission's promise has already arrived. The spacecraft has returned its first ultraviolet image, capturing an auroral substorm — a sudden, dramatic intensification of the aurora in Earth's polar regions. Auroras glow when charged particles from space funnel along magnetic field lines into the upper atmosphere, where they excite atoms and molecules that then emit light. Seeing this dynamic event in the mission's first ultraviolet view suggests the instruments are functioning well as the science campaign gets underway.

The declaration of readiness on 23 September means the commissioning milestones are behind the team. The spacecraft has proven its instruments, confirmed its orbit, and demonstrated that it can deliver the kind of observations scientists need. From this point on, Smile's data will flow to researchers studying the connection between the Sun and Earth.

The mission is a collaboration between Europe and China, combining the expertise and resources of both partners in a single spacecraft devoted to fundamental space science. Such joint ventures remain relatively rare, and Smile stands as one of the most prominent current examples of international cooperation in the study of near-Earth space.

With the science phase now underway, researchers will watch how Earth's magnetic bubble responds as the solar wind shifts in speed and density over time. Each orbit brings new opportunities to observe auroras, track disturbances, and piece together a more complete picture of how energy from the Sun transfers into Earth's environment.

The first ultraviolet image of an auroral substorm is an encouraging start. Over the coming months, Smile is expected to build a growing archive of observations that scientists can use to test ideas about how our planet interacts with its star.

For now, the milestone is simple but significant: the spacecraft is healthy, the instruments work, and the science has begun.