The past quarter century has witnessed the opening of a veritable golden age in planetary science. The 1990s saw major growth in exploration of the solar system. As the Voyager program’s series of planetary flybys was coming to an end an era of expanded, and more detailed, exploration of the solar system was ramping up. The Magellan mission to Venus and Galileo’s exploration of the Jovian system, along with the advent of NASA’s Discovery line of lower cost missions and a dedicated Mars exploration program, led to a vast increase in data about planetary objects. Of course, the previous twenty five years have also seen rapid and far-reaching improvements in computers, laboratory instrumentation, and Earth-based telescopes that have both quickened the pace and sharpened the detail of discovery.
The year 2016 also marks the 25th anniversary of the creation of what has become one of the primary venues for the publication of research in planetary science: the Journal of Geophysical Research: Planets (known better as JGR-Planets). This occasion is a good opportunity to look back at what we have learned in this era of expanded exploration and to try to take a peek at the future. To do this, we at JGR-Planets have spent over a year organizing a special collection of articles that highlight some of the most fundamental issues, the biggest discoveries, and critical open questions in planetary science. We also want to share this knowledge widely. Thus, each of the articles has been freely available since they were accepted for publication and will remain so until January 31, 2016. Then, like all articles in JGR-Planets, they will be freely available again two years after they first published.
AGU Publications / Wiley
Journal of Geophysical Research: Planets 25th Anniversary Edition
Planetary science is a broad field that covers every object in the solar system, except the Sun itself, and all of the processes that have shaped and reshaped these bodies for billions of years. So, as an editorial board we had to ask ourselves: as a scientific journal what would be useful to the planetary science community if we want to focus some attention on fundamental questions and discoveries in the field? Ultimately, our decision was to solicit a number of “review” papers that capture some of the most notable topics and discoveries of the past 25 years.
A review paper differs from a typical scientific article in that it focuses on collecting knowledge from many more typical papers and describing and assessing what that collective wisdom tells us about some “big picture” issue. Review papers are valuable because they condense or distill understanding of a scientific problem to its essential parts yet also direct readers to the relevant regular papers for more details. Review papers are a great way to catch up on, or start learning about, a particular scientific problem.
Planetary science has been on a steady diet of exploration and study the last 25 years and covering all of that in a single journal issue just isn’t practical. We made conscious choices to select topics from a range of bodies (from tiny chondrules to giant planets like Jupiter), and parts of planetary bodies (deep interiors to atmospheres), and the disciplines and techniques used to study the solar system. In the end, sixteen different topics were selected and authors were invited to write on these topics.
Identifying potential lead authors for the articles followed a similar pattern as for the topics themselves. Our goals were to identify knowledgeable scientists with appropriate expertise who were clear writers. We also aimed to include a variety of voices and approaches to the questions we posed. Review papers are often written by scientists with many years of experience. Yet in a period of expanding exploration of the solar system, the voices of scientists early in their careers provide a potentially different glimpse of what questions and approaches will also be important in the future. We also made sure to develop a list of potential authors that had a significant representation of women with the final list of authors influenced by who accepted our invitation to add writing a review paper to their workload this year. Ultimately, we have a list of authors spanning from early career scientists to some of the most experienced researchers in the field, from several countries, and six of the sixteen papers have women as first authors.
Figuring out how objects the size of chondrules eventually get put together into planets is an intense area of study and a lot of progress has been made in the past 25 years. While recent reviews of that work already exist, this paper takes a look forward and what questions remain. There are several, from understanding how the first large bodies are built to how our solar system ended up with its particular arrangement of planets. Then there is the origin of the Moon (Barr, 2016), which continues to fascinate us. While the idea of a giant impact between an approximately Mars-sized object with the Earth is the leading idea, the details necessary to explain the properties of the Moon have been the focus of study for decades.