Overview

• Hubble images captured on July 21 refined the nucleus size to between 320 m and 5.6 km, improving on earlier ground-based estimates.
• The telescope detected a dust plume and faint tail streaming from the nucleus, with a dust-loss rate matching that of Sun-bound comets.
• 3I/ATLAS travels at roughly 210,000 km/h, the fastest recorded speed for a Solar System visitor and evidence of its long sojourn through interstellar space.
• Most researchers now classify 3I/ATLAS as a natural comet, although Harvard astronomer Avi Loeb continues to argue for an artificial-probe hypothesis based on trajectory and glow anomalies.
• NASA is assessing whether Juno has enough fuel for a potential intercept, and ESA’s 2029 Comet Interceptor mission is being readied to rendezvous with future interstellar comets.