An interstellar comet passing through the solar system has triggered fresh scientific scrutiny after a Harvard astrophysicist warned it carries chemicals once used in warfare. The object, known as 3I/ATLAS, made its closest approach to Earth in December 2025, prompting questions about whether any of its material could pose a danger.
The warning came from Avi Loeb, a senior Harvard scientist, who highlighted the comet's toxic gas content and its historical links to WWI chemical weapons. Concerns focus on chemistry and physics, not intent, but the stakes are clear.
