Eric Mamajek, NASA Jet Propulsion Laboratory, Deputy Program Chief Scientist for NASA’s Exoplanet Exploration Program
The past year has been rather eventful on the exoplanet front. Over 1,500 confirmed exoplanets were added to the census of planets maintained at the NASA Exoplanet Archive in 2016, mostly from validation of Kepler Objects of Interest, or KOIs. Dozens of new planets were discovered and characterized from the K2 mission.
Two of the biggest discoveries over the past year involved finding Earth-size planets orbiting in the habitable zones around nearby stars: the nearest M dwarf Proxima Centauri, and the discovery of the amazing seven-planet transiting system TRAPPIST-1. Unfortunately Proxima Centauri b does not appear to transit its star, but the discovery has spurred numerous theoretical investigations of the properties of the planet, accounting for the properties of its host star. Recent results from characterizing the masses and radii of transiting exoplanets would seem to suggest that Proxima b is almost certainly a rocky world. The remarkable TRAPPIST-1 system contains no less than seven planets with radii ranging from about 71 percent to 113 percent of Earth's radius. The compact system of planets all orbit within about 10 million kilometers of their tiny host star.
Changes are afoot for the ExoPAG (Exoplanet Exploration Program Analysis Group). The ExoPAG Executive Committee (EC) helps organize the PAG's activities, including the chartering, researching, and writing of Study Analysis Group (SAG) reports on topics of general interest to the exoplanet community, and strategically important for planning and decision-making for large projects. The ExoPAG EC consists of a chair (currently Alan Boss) and nine rotating members serving three-year terms. ExoPAG EC members Maggie Turnbull, Lucianne Walkowicz, and Rus Belikov have recently completed their three-year terms, and we thank them for their years of service to the exoplanet community. Joining the ExoPAG EC membership of Daniel Apai, David Ciardi, Shawn Domagal-Goldman, Tiffany Glassman, Dimitri Mawet, and Tyler Robinson, we welcome new members Eliza Kempton, Michael Meyer, Chris Star, and Johanna Teske. Martin Still, the Exoplanet Exploration Program Deputy Program Scientist at NASA headquarters, serves as ExoPAG Executive Secretary and an ex officio member of the ExoPAG EC. We look forward to seeing exoplanet astronomers and ExoPAG members at the ExoPAG 16 meeting preceeding the Kepler/K2 SciCon IV meeting June 18th, in Mountain View, California.
Two community reports relevant to the future of NASA's exoplanetary science activities are on the horizon.
First, the president recently signed the first NASA authorization bill in seven years in March 2017: Bill S.442, the National Aeronautics and Space Administration Transition Authorization Act of 2017. Section 508 of the bill (labeled “Extrasolar Planet Exploration Strategy”), directs the NASA administrator to “enter into an arrangement with the National Academies to develop a science strategy for the study and exploration of extrasolar planets, including the use of the Transiting Exoplanet Survey Satellite, the James Webb Space Telescope, a potential Wide-Field Infrared Survey Telescope mission, or any other telescope, spacecraft, or instrument, as appropriate.” Hence, a new National Academies strategic plan on exoplanet science will be developed over the coming year, with the final report due to NASA and Congress during autumn 2018.
The second report on the horizon is the 2020 Decadal survey. The current NASA portfolio of missions and support projects follows the recommendations of the Astro2010 “New Worlds, New Horizons” report and the 2016 Midterm Assessment from the National Academies very closely. It now appears the 2020 decadal survey will be written in the year after JWST is launched so as to be able to factor in the state of astronomy after this flagship telescope's early science and discoveries start rolling in. There will be a period preceding this time when the community will be expected to contribute official white papers to this process. While this seems like the distant future, it is really right around the corner! Get involved. If the exoplanet community wants to build on its current momentum of progress and surprising discoveries, and wants to grow support from NASA (and NSF), exoplanet astronomers and ExoPAG members should start thinking now and organizing soon to take the lead on achieving some community consensus on outlining priorities for the future. Think big. The recommendation of the Astro2010 decadal survey led to the prioritization and formulation of the WFIRST mission (currently in phase A, and smoothly moving towards phase B in early 2017), which will advance microlensing and direct imaging detection of exoplanets from space. It also led to the "NN-Explore" NASA-NSF partnership for exoplanet research using the WIYN 3.5-meter telescope and the selection and development of the NEID spectrograph to be installed in early 2019. If the exoplanet community can come together and spell out priorities and project ideas with the support of many astronomers from a diverse range of subfields and institutions (including theorists, observers, and instrument builders alike), then the chances improve that this chorus can tip the needle toward building support for exoplanetary science projects in the 2020s.