In a groundbreaking step for planetary defense, the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) have formalized a memorandum of cooperation to strengthen their joint efforts. At the heart of this partnership is the Rapid Apophis Mission for Space Safety (Ramses)—a dedicated probe designed to study the near-Earth asteroid Apophis as it makes an extraordinarily close flyby in 2029. Here are ten essential things you need to know about this cosmic visitor and the mission that will track every change.