A small satellite can now verify the Outer Space Treaty

Researchers have proposed a new way to detect nuclear weapons in space using a small satellite. This means countries could finally check if others are breaking the Outer Space Treaty, which bans such weapons.

The Outer Space Treaty bans nuclear weapons in space, but for decades, no one knew how to verify compliance. This paper shows that a small, inexpensive satellite could identify a nuclear weapon in orbit. It means governments could move from worrying about violations to actually detecting them.