Current and Future Science of the Innermost Planet

Mercury: Current and Future Science of the Innermost Planet

In May 2018, the international Mercury science community gathered in Columbia, Maryland, for the Mercury:  Current and Future Science of the Innermost Planet meeting. In total, 123 scientists from 12 countries participated in the meeting, with 41% of the participants traveling from outside the United States to attend. The meeting focused on all scientific aspects of the planet Mercury, including both the current state of knowledge and the prospects for future endeavors. One of the major take-home messages from the meeting was that there is a sizable, active, and energetic international Mercury science community, and getting this community together for this meeting and in the future is productive and important.

One of the main reasons that there now exists a strong Mercury science community is because of the success of NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. MESSENGER provided a wealth of data about Mercury, and these data were the focus of many of the meeting’s presentations and discussions. Results from the MESSENGER mission have also motivated new experimental and modeling research, to interpret Mercury’s history and the processes that have acted on the planet in the past as well as those that continue to act in the present day. Ongoing observations from Earth-based telescopes were also presented, which further advance our understanding of Mercury’s surface, exosphere, and dynamical environment and enable studies of Mercury on longer timescales than any single mission.

Additionally, the Mercury science community is strong because the future spacecraft exploration of Mercury is set to continue. The joint ESA-JAXA BepiColombo mission is scheduled to launch in October 2018, and to arrive at Mercury in 2025. BepiColombo will be the first mission to deliver two spacecraft into orbit about Mercury, the Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter. The meeting included many discussions about BepiColombo’s plans, and the community expressed excitement and anticipation for the new measurements and potential new discoveries.

The three-day meeting was packed with diverse Mercury science topics from the 129 abstracts associated with the meeting. The oral sessions ranged from Mercury’s exosphere and magnetosphere, to the planet’s surface geology and composition, to the geophysical and geochemical structure of Mercury’s deep interior. A poster session with a reception was held on the first evening, with 33 posters making for lively discussions. E-posters are available on the meeting website from those participants who chose to make them available. One of the meeting participants, Emily Lakdawalla of The Planetary Society, wrote a wonderful story that highlights some of the scientific results presented at the meeting:

Between the presentations of Mercury science results and BepiColombo plans, one two-hour session of the meeting was devoted to discussions for the future exploration of Mercury, beyond BepiColombo. The session included presentations about efforts related to the last U.S. National Academies Planetary Science Decadal Survey, including an engineering study of a possible Mercury lander. Short presentations followed where scientists laid out some of the top-priority science questions that could drive the future exploration of Mercury. The session ended with a discussion of what the Mercury community should do going forward, to keep the community strong and to keep Mercury as a compelling option for future missions. Along with continuing special Mercury-focused sessions at planetary science meetings, there was a strong sentiment that meetings like the current one should occur in the future. Happily, plans are already underway in setting the dates and location for the Mercury 2020 meeting!

The discussion also showed that there is strong support for the importance of future Mercury exploration missions beyond BepiColombo. At the meeting, a poster was hung to enable community members to brainstorm possible future Mercury exploration ideas and to sign up to be involved in future efforts. In total, 74 individuals signed up, demonstrating the strong support for the future exploration of Mercury. Possible next steps for the Mercury community that were mentioned included writing white papers and forming a group similar to the Analysis or Assessment Groups that other planetary science communities have, such as SBAG, OPAG, VEXAG, MEPAG, and LEAG. Mercury currently does not fit within any of these existing analysis groups. Interestingly, discussions subsequent to the meeting revealed that NASA’s Planetary Science Advisory Committee discussed the need for a Mercury analysis group at their February 2018 meeting and drafted a finding to support the formation of such a group. It will be important to see how all of this strong interest and support for future Mercury exploration develops over the next few months.

Overall, the Mercury 2018 meeting was a great success and is positioned to be the first in a regularly occurring series. It was encouraging that among the meeting participants there were 23 students, and it was greatly appreciated that LPI was able to provide 10 early career scientists with travel support awards. The meeting was highly productive but also showed that there is still much to be answered about Mercury, through continued research with MESSENGER and other datasets, through BepiColombo’s unprecedented two spacecraft measurements, and through future exploration of our solar system’s innermost planet.

For more information, and to view the program and abstracts, visit the workshop website at