Windows On The Universe: The Era Of Multi-Messenger Astrophysics

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 to promote the progress of science, advance national health, prosperity, and welfare, and secure national defense. Within NSF, the Divisions of Astronomical Sciences (AST), Physics (PHY), and the Office of Polar Programs (OPP) collaborate on initiatives to expand the frontiers of discovery across the sciences. One such initiative is the Windows on the Universe: The Era of Multi-Messenger Astrophysics (WoU-MMA) program, which seeks to harness the combined power of multiple astrophysical messengers—electromagnetic radiation, high-energy particles, and gravitational waves—to revolutionize understanding of the universe. The WoU-MMA program builds on the rapid growth of observational capacity over the past decade, where scientists have successfully detected signals across different messenger channels. The integration of these data streams enables astrophysicists to explore fundamental questions about matter, energy, and the origins of the cosmos in ways not possible with single-method observations. Through this program, NSF aims to foster synergistic activities that will accelerate scientific discovery, enhance community coordination, and strengthen U.S. leadership in astrophysics. Applicants may propose projects in three primary areas: coordination of observations across messengers, observations of astrophysical objects or phenomena that emit multiple signals, and interpretation through theory, modeling, or simulations. Competitive proposals will demonstrate a strong multi-messenger component and advance community capabilities developed in the first five years of the program. Projects that integrate research communities across observational and theoretical domains, and that train new scientists in this emerging field, are particularly encouraged. Proposals solely focused on single-messenger studies without a clear integration plan will be considered within the relevant NSF disciplinary program but not under WoU-MMA. Funding is available for proposals submitted through related programs such as Astronomy and Astrophysics Research Grants, Plasma Physics, Gravitational Physics, and Particle Astrophysics. Applicants should carefully review program-specific deadlines as WoU-MMA is designed to function within existing NSF structures. Submissions must follow the NSF Proposal & Award Policies & Procedures Guide (PAPPG) or the NSF Grants.gov Application Guide, depending on the submission portal. Titles of proposals seeking WoU-MMA consideration must begin with the acronym "WoU-MMA:". The program accepts full proposals during designated annual windows. For example, the Astronomy and Astrophysics Research Grants window runs from August 15 to October 15 annually, while the Plasma Physics program deadline is the fourth Wednesday in November. Additional deadlines vary by participating division, with recurring annual cycles. Applicants are responsible for ensuring compliance with submission requirements and deadlines. Proposals received outside the posted dates may be returned without review. Program oversight is provided by designated NSF contacts in AST, PHY, and OPP. Among them are Hans Krimm, Nigel Sharp, and Martin Still for Astronomical Sciences; Vyacheslav Lukin and Pedro Marronetti for Physics; and Vladimir Papitashvili for Polar Programs. Each contact can provide guidance on program fit and submission processes. Proposers are strongly encouraged to reach out to relevant program directors if uncertain about program alignment. In summary, the WoU-MMA program provides a pathway for researchers to expand the horizons of astrophysics through coordinated, cross-disciplinary studies that merge electromagnetic, particle, and gravitational-wave data. By supporting projects that enhance interoperability, build workforce capacity, and integrate theoretical and observational approaches, NSF ensures that the scientific community is equipped to unlock the mysteries of the universe through the power of multi-messenger exploration.