Overview

• JWST NIRSpec observations from August 6, released August 25, show a coma dominated by carbon dioxide with a CO2-to-H2O ratio of about 8, alongside detections of CO, H2O and water ice.
• Hubble imaging on July 21 constrains the nucleus to no larger than roughly 5.6 km across and reveals a compact dust coma consistent with active cometary behavior.
• NASA’s SPHEREx mapped a CO2 coma extending at least 348,000 km and estimated a CO2 production rate near 9.4×10^26 molecules per second (about 69 kg/s), with low upper limits on water and carbon monoxide outgassing.
• Precovery analyses of TESS and Rubin Observatory data indicate the object was already active months before discovery, likely driven by hypervolatile ices such as CO2 and CO at large heliocentric distances.
• Trajectory solutions confirm an interstellar origin and speeds exceeding 130,000 mph, with perihelion around October 29–30 at about 1.4 AU and closest Earth approach in mid‑December at ~1.8 AU, and NASA notes no impact risk; isolated claims of unusual nickel or cyanide emissions and technological origins remain uncorroborated.