The identification of grand challenges can be a powerful tool for encouraging concerted efforts toward important goals, whether in research or other endeavors. For example, the National Science and Technology Council [2005] report entitled “Grand challenges for disaster reduction” targeted the handling and mitigating of natural hazards on Earth. Are there grand challenges in understanding the natural hazards of space weather, the solutions to which would transform forecasting, prediction, or systems design? Would specifically identifying several such challenges foster focused and transformational research that would arrive at solutions more quickly? The objectives of Space Weather include the advancement of the practical applications of solar and geospace research. Papers published in this journal are targeted to this objective, guided by the editor's reviews and by the formal peer-review process. But how many papers published here have been motivated by the most critical problems facing the users of space weather information? Is there indeed a set of critical problems that require substantially more effort, and are such problems even recognized if they exist? I believe that one grand challenge could be developing how to predict the electromagnetic amplitude and spectral characteristics of a solar X-ray and radio burst event with sufficient lead time to be useful (approximately 3 hours prior to eruption). Such events immediately affect the upper atmosphere of Earth and can severely disturb—and even totally disrupt—radio signals that transit through or are reflected by the ionosphere. These bursts pose an increasing hazard as society expands its use of navigation methods based on global positioning systems. At present, the events, and therefore their impacts, occur without warning. Not only can an electromagnetic event not be predicted with a 3-hour warning, but also any prediction of an event contains no information of its electromagnetic characteristics or its duration. Do you, the readers of Space Weather, agree that predicting solar X-ray and radio burst events may be a grand challenge for space weather research? What other grand challenges exist for our field of research and its applications? Or do you think that such challenge identifications are likely a waste of time and would accomplish little? The journal welcomes and encourages opinion articles that address the questions raised in this editorial. Let us hear from you! National Science and Technology Council (2005), Grand challenges for disaster reduction, 26 pp., Off. of Sci. and Technol. Policy, Washington, D. C. Louis J. Lanzerotti is editor of Space Weather and a distinguished research professor at the New Jersey Institute of Technology, in Newark.