Smile captures the full northern aurora as science observations begin
The European–Chinese Smile spacecraft has released ultraviolet footage of the entire northern auroral oval during a magnetic disturbance. The image marks the start of science operations and offers a way to follow changes around the whole polar ring. Its separate X-ray camera has passed tests on distant objects, but stray light still prevents the planned image of Earth’s magnetic boundary.
Science··Evening
A whole auroral ring comes into view
Smile, a spacecraft jointly operated by the European Space Agency and the Chinese Academy of Sciences, has released its first ultraviolet footage of the northern auroral oval. The camera recorded the images on 24 July, during in-orbit checks, and ESA published them on 30 September as the mission entered science operations. The ring changes shape in the sequence during a substorm, a disturbance caused when particles from the Sun interact with Earth’s magnetic field. Ultraviolet light is largely absorbed by the atmosphere, so the view from orbit shows changes across the complete ring that individual ground stations cannot see at once.[1], [2]
Science instruments begin their observations
The European–Chinese mission was cleared to begin science work on 23 September, after launch in May and arrival in its working orbit in June. Teams had been deploying mechanisms, checking communication and switching on four instruments. Alongside the ultraviolet imager, Smile carries a soft X-ray camera, a magnetometer and a light-ion analyser. ESA says the ultraviolet camera can watch the auroral ring for up to 45 hours at a time. That extended view lets researchers follow how the polar display responds as the solar wind changes, rather than assemble separate glimpses from different positions on Earth.[1]
Earth-facing X-rays await a clearer view
The soft X-ray camera has produced test images of distant supernova remnants, including one in the Large Magellanic Cloud and Cassiopeia A. It has yet to produce the intended science image of the magnetopause, the boundary where the solar wind presses against Earth’s magnetic field. When the instrument faces Earth, stray light overwhelms that signal. Engineers are changing camera settings and spacecraft software, while ESA expects less stray light as northern winter approaches. The released auroral footage is therefore an observation already made; the X-ray view of the magnetic boundary remains a measurement the team is still working toward.[1]
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