Smile reveals the auroral ring as science operations begin

ESA’s 30 September commissioning report says the joint European–Chinese Smile mission was cleared for science operations on 23 September. Its ultraviolet camera can follow the entire northern auroral ring for up to 45 hours at a time.

The original image shown here was captured on 4 August, during commissioning. The luminous oval records ultraviolet emission around the North Pole; it is not a photograph in colours a human observer would see. ESA also released a July observation sequence. Watch how the ring changes, rather than reading this one frame as a forecast.

That broad view matters because auroras connect activity at the edge of Earth’s magnetic field to the upper atmosphere. Earlier spacecraft could follow the auroras for about 15 hours continuously, according to ESA’s instrument explanation. Ultraviolet observation also makes the daylight portion of the ring easier to see. Longer coverage can help researchers follow a disturbance through more of its evolution.

The complementary X-ray instrument is not yet delivering the intended Earth-facing view: excess stray light is interfering. Teams are adjusting settings and software, and ESA expects naturally lower stray light around mid-October to help. Successful tests on a distant stellar remnant do not establish that this problem is solved.

For now, this is an observing milestone, not a demonstrated improvement in storm warnings. The useful next step is to compare the still with ESA’s original time sequence. The sequence records July; the still records August. They are different observations, released together in September.