Overview

• An arXiv study of ZTF images extends 3I/ATLAS detections to about 17 au and finds activity at least inward of 6.5 au, with a steep r_h^-3.8 brightening consistent with dynamically old comets.
• Dust production estimated by ZTF rose from roughly 5 kg/s in early May at ~6 au to ~30 kg/s by mid-July near ~4 au, aligning with Hubble-derived activity at ~3.8 au and suggesting CO2-driven outgassing that likely began near ~9 au.
• NASA’s Tom Statler says the object “behaves like a comet,” and the agency reports no threat to Earth, forecasting a minimum approach of about 170 million miles as it passes inside Mars’s orbit in late October.
• Multiwavelength observations indicate a CO2-rich coma, a growing dust tail, a nucleus no larger than about 5.6 km across, and an exceptionally high inbound speed near 130,000–137,000 mph.
• TESS precovery work from MSU points to earlier-than-expected activity at large distances, and some reports describe features such as an apparent anti-tail and color changes that remain under study.