团队使用位于加那利群岛特内里费的两米双子望远镜，于 2025 年 7 月 2 日至 9 月 5 日共 37 个夜晚追踪彗发演化：8 月前以朝日的尘埃扇形为主，之后转为明显的背日尾，并将此趋势归因于随著接近近日点而增强的太阳辐射对尘埃的影响。近日点为 2025 年 10 月 30 日，距太阳约 1.30 亿英里（2.10 亿公里）。
喷流在 8 月 3 日至 8 月 29 日的 7 个夜晚于反尾内出现；其进动式摆动暗示彗核自转周期约 15 小时 30 分钟，且比先前估计更短。3I/ATLAS 是已知第三个来自其他恒星系进入太阳系的天体（前两个为 2017 年 10 月发现的『欧陌陌』与 2019 年 8 月的 2I/Borisov），而这也是首次在星际彗星上观测到此类「放气」喷流。
Research on interstellar comet 3I/ATLAS reports unusual jet structures inside a rare sun-facing “anti-tail.” Some observations estimate the anti-tail extends up to about 620,000 miles (1 million km), and the jets were seen wobbling with a 7 h 45 min periodicity as the comet approached the Sun.
Using the Two-meter Twin Telescope in Tenerife, researchers observed 3I/ATLAS across 37 nights from July 2 to Sept. 5, 2025. Over time the coma shifted from a pre‑August sun-facing dust fan to a pronounced anti-solar tail, consistent with increasing solar-radiation effects as the comet neared perihelion on Oct. 30, 2025 at ~130 million miles (210 million km) from the Sun.
Jets appeared within the anti-tail on 7 nights between Aug. 3 and Aug. 29; their precession implies a nucleus rotation period of ~15 h 30 min, shorter than earlier estimates. 3I/ATLAS is only the third known interstellar visitor (after ’Oumuamua in Oct. 2017 and 2I/Borisov in Aug. 2019), and this is the first reported observation of such outgassing jet behavior from an interstellar comet.
