Rare Interstellar Comet 3I/ATLAS – a 10-Billion-Year-Old Time Capsule – Flies Past Mars
Comet 3I/ATLAS, discovered July 1, 2025, is the third confirmed interstellar object to enter the Solar System. In October, it passed within 30 million km of Mars, allowing ESA orbiters to capture images despite its extreme faintness. The comet’s nucleus measures up to 6 km across and is rich in carbon dioxide and water ice. Astronomers estimate it formed about 7 billion years ago, making it potentially the oldest comet ever observed.