Introduction:
The Director has accepted the recommendation by the Working Group on Strategic Planet Initiatives to undertake a joint JWST/HST Director’s Discretionary program to characterize the atmospheric properties of terrestrial-mass exoplanets around nearby low-mass stars. Around 500 hours of JWST time and 250 orbits of HST time will be devoted to the Rocky Worlds program starting in 2024 (Cycles 3 and 32) and likely extending through early 2027. The observations will include mid-infrared observations of multiple secondary eclipses of more than a dozen transiting exoplanets and characterization of selected host star properties at UV wavelengths. The data taken will be rapidly released to the community and STScI will produce high-level data products.
STScI as an institution must maintain the highest level of integrity in its treatment of the observations, analysis tools and high-level data products associated with the Rocky Worlds program. STScI staff members are entitled to pursue scientific research with public JWST and HST data. However, additional considerations apply when they have access to calibration and analysis tools or to high-level data products that are being developed with HST or JWST Project funds and are not yet public. STScI Policy III-B-7 gives general guidelines on ethical use of data; this document covers issues that are specific to the Rocky Worlds program.
Structure:
The final design and implementation of the data program and the production of high-level data products will be undertaken by a Core Implementation Team (CIT), working in conjunction with the Science Advisory Committee (SAC). The overall program will be coordinated by the CIT Lead and their Deputy, who has the final authority for decisions. The CIT Lead is the Exoplanet Mission Scientist, Nestor Espinoza, and Hannah Diamond-Lowe will serve as the Deputy. They will be assisted by an observing technical lead and data technical lead. The JWST Mission Head, Tom Brown, the Interim HST Mission Head, Julia Roman-Duval, the Associate Director for Science, Mercedes Lopez-Morales and the Multi-Mission Project Scientist, Neill Reid, will serve as a Program Advisory Council (PAC) to provide advice on high-level issues, as needed.
Core Implementation Team
The CIT will be responsible for preparing the APT observing proposals, designing and implementing the observing schedule, processing the data, and preparing the high-level data products. CIT members will be drawn from the STScI staff. The CIT Lead may convene topic-specific working groups related to the implementation. The CIT Lead or their designate will keep the general community informed of progress, including regular briefings to the Space Telescope User Committee and the JWST User Committee, and public presentations at general fora such as the AAS. They will provide an avenue for receiving their input from the user committees and the general community.
Science Advisory Council
The SAC comprises 10-12 research scientists from the community who are committed to providing scientific advice to the CIT on scientific aspects of the implementation process. Members are expected to
- Advise the Core Implementation Team on scientific aspects of the implementation process, including the selection of appropriate targets, the observing strategy, and feedback throughout the data gathering and analysis stages.
- Advise STScI on interactions with the broader community, particularly with regard to the release of all data products and paths to achievement of the scientific objectives of the program.
- Assist in the definition and science verification of high-level science products generated by the CIT, including advice on potential program adjustments
The SAC is not expected to meet in person. Meetings will be fully virtual and much of the business will be carried out asynchronously (email, google docs, etc).
Members of the SAC will not participate in functional activities connected with the program implementation. Their role following the acquisition of data will be limited to the verification of high-level data products and analysis tools prior to their release to the general community. The SAC will not be involved in scientific data analysis or publication prior to the public release of high-level data products.
SAC Membership
To establish continuity, three members of the Working Group have agreed to serve on the SAC:
Natasha Batalha (NASA Ames), Kevin France (Colorado) and Laura Kreidberg (MPIA).
STScI issued a call for nominations in early August 2024. The call was open to observers, data analysts, theorists, and modelers with experience related to terrestrial exoplanets and their M dwarf hosts. Please see the Dear Colleague SAC Nomination letter for more information. The deadline for submissions was August 27, 2024.
Over 60 submissions were reviewed by the WG SAC members, in consultation with the PAC. Nine additional members were selected based on their expertise and willingness to support the broader community. The final SAC membership is as follows:
Natasha Batalha (NASA Ames), Kevin France (Colorado), Laura Kreidberg (MPIA), Kevin Stevenson (APL), Allison Youngblood (GSFC), Megan Mansfield (U. Maryland), Adina Feinstein (MSU), Rory Barnes (Washington), Bjorn Benneke (Montreal), Daniel Koll (Peking University), Aishwarya Iyer (GSFC) and Rafael Luque (Chicago).
Target Selection
The Rocky Worlds program will have a carefully selected target list of terrestrial exoplanets orbiting M dwarf host stars. The targets will be selected by the SAC in consultation with the community. Please see the Dear Colleague Targets letter and the Targets Under Consideration list for more details. An initial set of high priority targets will be identified by September 15 2024, one month in advance of the JWST Cycle 4 proposal deadline. This will allow the community to propose supplementary and complementary GO programs. Further targets will be added once the Cycle 4 science program is announced. GO programs will generally have priority on specific observations.
Data Release Schedule
Each Rocky Worlds target will require multiple eclipse observations with JWST to search for evidence of atmospheres; a subset of host stars will be targeted for UV observations with HST. Those observations will be interspersed with other GO and DD programs throughout each cycle. For each target, the eclipse data will be combined by STScI and the final data product, together with the raw data files, will be made public through MAST, likely after all observations of that particular target are taken. This follows the recommendation of the Working Group to provide open access (see below for restrictions for CIT and SAC members). HST observations of the host stars will be non-proprietary and will likely be available immediately. The SAC will determine the final release schedule.
Policy Requirements
General:
- The program implementation will be designed to achieve the science goals articulated by the Working Group on Strategic Planet Initiatives
- Any data products or analysis tools developed in the course of the Rocky Worlds program may not be used for personal research until they are made available to the general community.
SAC
- SAC members may not participate in submitting any publications based on Rocky Worlds DD observations until that dataset has been public for at least 2 weeks.
- SAC members may participate in HST or JWST proposals based on, or supplementing, data taken for the Rocky Worlds program and/or enhanced data products associated with that program provided that the relevant datasets are publicly available at least 2 weeks before the proposal deadline.
- There is no restriction on SAC members receiving funding for programs associated with Rocky Worlds.
CIT
- STScI staff working on the implementation team must clearly separate their functional work from any scientific research undertaken using these data or associated tools and data products.
- CIT members may not participate in submitting any publications based on Rocky Worlds DD observations until that dataset has been public for at least 2 weeks.
- Members of the CIT may not serve as PIs on HST or JWST proposals that are associated directly with the Rocky Worlds programs. Those proposals include AR programs that aim to utilize Rocky Worlds data, Theory programs designed to support analysis of those data, or observing programs that aim to supplement the Rocky Worlds datasets.
- Members of the CIT may participate as co-Is in HST or JWST proposals that are associated with the Rocky Worlds programs. They must inform the CIT lead of their involvement in those proposals and they may not apply for or receive grant funding if those proposals are accepted.
Core implementation team leads: Roles and responsibilities
Implementations team lead
- Overall responsibility for program implementation, in consultation with the SAC and the scientific community
- Functions include target selection, observing strategy, instrument configuration, coordination of observations with those from other facilities, communications strategy, and concept for high-level data product
Implementation team deputy
- Responsibility for the technical implementation of the observations
- Functions include development of APT files, planning the detailed schedule, oversight of the observation execution, and working with staff in the instrument and scheduling branches