  Particle colliders have arguably been the most important instruments for
particle physics over the past 50 years. As they became more powerful, they
were used to push the frontier of our knowledge into previously uncharted
territory. The LHC, the highest energy collider to date, at which the Higgs
boson was discovered, is a prime example. To continue along the road into the
Terra Promissa beyond the Standard Model requires colliders with energy reach
even greater than that of the LHC. Beams of muons offer enormous potential for
the exploration of the energy frontier. Since the muon is a fundamental
particle, its full energy is available in collisions in contrast to protons
which are composed of quarks and gluons. However, muon beams decay rapidly,
which presents a special challenge for a collider. Recent research indicates
that the technologies required to overcome this challenge are within our grasp
and may offer a cost-effective and energy-efficient option to continue our
explorations. A new international collaboration is forming to bring together
the diverse expertise and complementary capabilities from around the world to
realize the muon collider as the next-generation energy-frontier discovery
machine.
