Overview

• Fresh Gemini South data reveal a developing tail and glowing coma around 3I/ATLAS, with spectra offering first chemical clues.
• NASA’s Tom Statler says the object behaves like a natural comet and will stay at least about 1.6 AU (roughly 170 million miles) from Earth.
• 3I/ATLAS is the third confirmed interstellar object and is estimated to have a nucleus near 5.6 kilometers in diameter.
• TESS precovery images indicate the comet was active earlier than first thought, likely driven initially by volatiles such as CO or CO2 before strong water outgassing.
• The comet will pass behind the Sun at perihelion in late October and is expected to become observable again from Earth by early December.