This Commentary is being written in an uncertain and pivotal time in U.S. history. At unprecedented levels, many elected officials and political appointees are ignoring evidence-based science in policy making, politicizing science, and questioning the importance of Federal investments in basic science research [e.g., Science News Staff, 2017]. U.S. scientists are concerned that the free sharing of science research is in jeopardy [Mervis, 2017]. The authors reaffirm the core beliefs that science should be nonpartisan, basic science research is crucial to the advancement of society, and any attempt to politicize or suppress science is detrimental and should be opposed. In the recent words of Rush Holt, the current chief executive officer of the American Association for the Advancement of Science (AAAS) and a former U.S. Representative, “Science is not just for scientists” [Gaal, 2017]. This could not be more true of the field of space physics. In this Commentary, we discuss what space physics is, its societal relevance and its impact on U.S. policy. A number of pieces have been written about the related topic of space weather [Baker, 2002; Baker and Lanzerotti, 2016] and its societal and policy impacts [Fry, 2012; Lanzerotti, 2015; Schrijver, 2015; Jonas and McCarron, 2015; Cassak, 2016; Gaunt, 2016; Bonadonna et al., 2017]; the emphasis for this Commentary is the broader field of space physics.

۲٫ What Is Space Physics?

Space physics is the study of Earth’s home in space. Space physics is a broad field with a rich history; it includes (1) the study of how the Sun works from its interior to its surface and its atmosphere (the corona), including the causes of eruptions on the Sun marking times of high solar activity, (2) the characterization of the environment between the Sun and the planets out to the interstellar medium, including the solar wind and energetic cosmic rays from outside the solar system, (3) the study of the interaction of the magnetic barriers (magnetospheres) surrounding Earth and other planets with the interplanetary environment, particularly during times of high solar activity, and (4) the study of Earth’s ionized upper atmosphere (the ionosphere) and its interaction with Earth’s neutral lower atmosphere.