PLANETARY EXPLORATION NEWSLETTER Volume 20, Number 16 (April 19, 2026) PEN Website: https://planetarynews.org Editor: Matthew R Perry Co-Editors: Alex Morgan, Mark V. Sykes Email: pen_editor@psi.edu X: @pen2tweets Bluesky: @planetarynews.bsky.social o-------------------------TABLE OF CONTENTS---------------------------o 1. OPAG Virtual Community Meeting Reminder and Logistics for April 20 2. PDS Geosciences Node Virtual Open House - April 21 3. Machine Learning for Planetary Science and Space Physics (ML4PSP) Seminar Series 2026 - Relaunch Announcement 4. Planetary Crater Consortium: Registration and Abstracts are Open 5. Save the Date: Workshop on the Integrated Science of Comets 6. Postdoc Position at Brown University 7. Ph.D. Position in Asteroid Modeling and Observations 8. [EPSC2026] Session EXOA8: Organic Chemistry in the Outer Solar System and Beyond 9. [EPSC2026] Session ODAC7: Diversity and Inclusiveness in Planetary Sciences 10. [EPSC2026] Session SB6: Interstellar Targets of Opportunity - Science from Interstellar Objects, Past, Present and Future 11. [NASA] SMD: Q&A for the Lunar Science and Technology Payloads RFI 12. [NASA] ROSES-25 Amendment 52: NASA SMD Graduate Student Research Solicitation - Future Investigators in NASA Earth and Space Science and Technology 13. [NASA] Call for Reviewers: NASA Space Grant - AI Workforce Development 14. Planetary Meeting Calendar Additions 15. Planetary Science Journal - New Papers 16. Journal of Geophysical Research: Planets - New Papers o---------------------------------------------------------------------o 1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1 OPAG VIRTUAL COMMUNITY MEETING REMINDER AND LOGISTICS FOR APRIL 20 This is a reminder that on Monday, April 20, 2026 we will be hosting a virtual community meeting starting at 12:30 pm Eastern / 9:30 am Pacific which will include updates and a Q&A session with our Planetary Science Division (PSD) Director, Dr. Louise Prockter. Information and registration can be found here: https://www.lpi.usra.edu/opag/meetings/april2026/ There is no registration fee, but you must be registered to participate. We encourage you to submit and upvote questions ahead of the meeting so we can best utilize our time with Director Prockter. Please submit questions here: https://tinyurl.com/OPAG202604 We strongly encourage the community to watch the updates relevant for the OPAG community from PSD that were presented at the LPSC meeting in March: NASA Headquarters Briefing (Dr. Louise Prockter and Dr. Brad Bailey): https://www.youtube.com/watch?v=Srof-LqPqBw&t=824s NASA Headquarters Planetary Research Briefing (Dr. Kathleen Vander Kaaden & Dr. Aaron Burton): https://www.youtube.com/watch?v=N8-enBzNwlo&t=321s Thank you for your continued engagement through this transitional time. If you'd like to continue to receive emails from OPAG after April, make sure you've signed up for our OPAG list-serve here: https://forms.gle/PAmfgibKjZNfpTt3A All the best, Carol & Morgan OPAG Co-Chairs 2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2-2 PDS GEOSCIENCES NODE VIRTUAL OPEN HOUSE - APRIL 21 The PDS Geosciences Node will host a virtual Open House on Tuesday, April 21, 2026 at 2:00 pm Central. This event is open to all members of the planetary community and is an opportunity to hear an update from and ask questions of GEO Node personnel. The Open House will start with a ~40-minute presentation covering an overview of the Geosciences Node, our tools and services, recent achievements, our transition of PDS GEO data to the cloud, and priorities for the year ahead. The presentation will be followed by a Q&A session. Additional information and meeting connection details may be found here: https://pds-geosciences.wustl.edu/openhouse/openhouse2026.htm Optionally, you may indicate your interest and receive a meeting reminder via this link: https://forms.cloud.microsoft/r/pmvxukzE4Q We look forward to seeing you! 3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3 MACHINE LEARNING FOR PLANETARY SCIENCE AND SPACE PHYSICS (ML4PSP) SEMINAR SERIES 2026 - RELAUNCH ANNOUNCEMENT The Machine Learning for Planetary Science and Planetary Exploration (ML4PSP) Seminar Series is back for 2026. This seminar series aims to bring together researchers in planetary science, space physics, machine learning, and other domain applications of data science. From hyperspectral data analysis to foundation-model applications on planetary datasets, ML4PSP highlights emerging methods that are shaping the future of planetary exploration. We welcome researchers, students, and practitioners from across disciplines to join, learn, and engage with this growing community. Upcoming Seminar: April 21, 2026 at 9:00 AM Pacific Time Speaker: Jichao Fang (Northern Illinois University) Title: Planetary-Scale Similarity Search for Mars Orbital Imagery with Foundation-Model Embeddings Full schedule and abstract: https://ml4psp.github.io/ Zoom Link: https://tinyurl.com/59d489yf Meeting ID: 935 6088 0593 Passcode: ml4psp Organized by the ML4PSP Team Ramana Sankar, Dona Kuruppuaratchi, Indhu Varatharajan 4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4 PLANETARY CRATER CONSORTIUM: REGISTRATION AND ABSTRACTS ARE OPEN It's time to save the date for the upcoming Planetary Crater Consortium (PCC) Meeting this July: 1) The dates for our 2026 meeting are July 15-17. It will be held at the USGS-Flagstaff in Flagstaff, AZ, USA; we will still support remote attendance and speakers. If you would like to consider hosting the PCC at your organization in future years, please come to the meeting with a proposal and we will vote on it. 2) Abstract submission and registration for this year's meeting are officially open! As with last year, Registration and Abstract submission for this year's meeting will be handled by Google Form: Abstracts: https://forms.gle/APaNS8G7ycJxNrQdA Registration: https://forms.gle/RpGWUMaK6qdkKWKK6 3) The deadline for abstract submission is June 17, 2026. Also keep your calendars open for a potential July 18 field trip in the Flagstaff area. 5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5-5 SAVE THE DATE: WORKSHOP ON THE INTEGRATED SCIENCE OF COMETS The LPI is pleased to announce the Workshop on Integrated Science of Comets: From Laboratory Studies of Cometary Materials to Remote Observations, to be held September 22-24, 2026, at the Lunar and Planetary Institute in Houston, Texas. The workshop brings together the international community working on interplanetary dust particles, cometary samples, and comet observations. Marking the 20th anniversary of the Stardust sample return, it will highlight two decades of advances in cometary sample science while integrating new insights from space and ground-based observations across optical, infrared, and radio wavelengths, including JWST, Hubble, and major ground-based observatories. By connecting laboratory analyses, multi-wavelength remote sensing, and mission science, the workshop aims to develop a cohesive understanding of cometary materials and their role in Solar System formation, and to define key science priorities for future comet exploration and sample return missions. To submit an indication of interest and learn more, visit: https://www.hou.usra.edu/meetings/integratedsciencecomets2026/ 6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6 POSTDOC POSITION AT BROWN UNIVERSITY The Department of Earth, Environmental and Planetary Sciences at Brown University invites applications for a University Fellowship in Earth, Environmental and Planetary Sciences. This competitive postdoctoral fellowship will be awarded for a one-year period, with possible extension for a second year. Postdoctoral associates will conduct independent research in association with Brown faculty in Earth, Environmental and Planetary Sciences. For more information and to apply, please visit: https://apply.interfolio.com/183852 7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7 PH.D. POSITION IN ASTEROID MODELING AND OBSERVATIONS The Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA) offers a four-year PhD position at the interface of observations and numerical modeling of asteroids. The observational component involves working with new and archival imaging data to derive astrometric and photometric measurements, identify fast-moving and potentially active objects, and support their rapid characterization. The candidate will contribute to developing analysis tools and selecting targets for follow-up observations. The numerical component focuses on modeling the dynamical and thermal evolution of asteroids. This includes applying and extending existing models, investigating objects with limited observational constraints, and developing improved methods to estimate physical properties and their uncertainties. The exact PhD program will be tailored to the candidate's background and interests, with flexibility in the balance between observational and modeling components, and carried out under the supervision of Dr. Bojan Novakovic. The position is based in Teruel, Spain, and includes salary, and standard employment benefits in accordance with Spanish regulations, with flexible working hours. Full further information and application instructions: https://www.cefca.es/cefca_en/reference_0144 8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8-8 [EPSC2026] SESSION EXOA8: ORGANIC CHEMISTRY IN THE OUTER SOLAR SYSTEM AND BEYOND The "Organic Chemistry in the Outer Solar System and Beyond" session at EPSC 2026 in The Hague, Netherlands, looks to bring together the outer Solar System and astrochemistry communities for discussions on carbon chemistry and implications for astrobiology. This symposium will explore our understanding of carbon chemistry in the outer Solar System and beyond. We invite contributions related to icy ocean worlds (core, seafloor, ocean, surfaces, gas-phase), cosmic dust (interstellar, interplanetary, circumplanetary, etc.), ring systems, comets, asteroids, surfaces, Trans-Neptunian Objects (TNOs), protoplanetary disks, and the interstellar medium (ices, molecules, ions, and gas-phase). We welcome submissions that present results derived from space mission data, detections of organic molecules through telescopic observations, laboratory experiments predicting or characterizing chemical processes, and theoretical approaches including quantum chemistry and geochemical modeling. Contributions in astrobiology and related astrochemical implications are also encouraged. Session details: https://www.epsc2026.eu/session/59288 Abstract submission information: https://www.epsc2026.eu/programme/how-to-submit.html The abstract deadline is the 13 May 2026 (13:00 CEST). Convenors: Thomas R. O'Sullivan, Melissa K. McClure, Grace Richards, Partha P. Bera, Nozair Khawaja 9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9 [EPSC2026] SESSION ODAC7: DIVERSITY AND INCLUSIVENESS IN PLANETARY SCIENCES The benefits of diversity and inclusiveness in the scientific community are incontrovertible. Following the success of previous years, this session aims to foster debate within the planetary sciences community about the reasons behind the under-representation of different groups (gender, cultural, ethnic origin, national, and ableism) and best practices to make the research environment more inclusive identifying and addressing barriers to equality. We invite abstracts focusing on under-representation (gender, cultural, ethnic origin, national, and ableism) supported by statistics and data; outreach and education activities to reach broad and diverse audiences, best practices to support inclusiveness; and case studies on mentoring and bias-concerned activities. Please, submit you abstract here: https://meetingorganizer.copernicus.org/EPSC2026/session/59317 The deadline for the abstract submission is 13 May 2026, 13:00 CEST. We look forward to welcoming you in The Hague in September, The conveners Arianna Piccialli, Solmaz Adeli, Ann Carine Vandaele 10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10-10 [EPSC2026] SESSION SB6: INTERSTELLAR TARGETS OF OPPORTUNITY - SCIENCE FROM INTERSTELLAR OBJECTS, PAST, PRESENT AND FUTURE 6-11 September 2026 in The Hague, The Netherlands This session invites presentations on science results from terrestrial and spacecraft observations of all three known Interstellar Objects (ISO), on how the lessons learned from their observation can be applied to future interstellar targets of opportunity, and on plans for future ISO interceptor missions. Session details: https://www.epsc2026.eu/session/59163 Deadline: 13 May 2026 (13:00 CET). Conveners: Thomas Marshall Eubanks, Michael Kuppers, Quanzhi Ye, Andreas Hein, Olivier Witasse 11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11-11 [NASA] SMD: Q&A FOR THE LUNAR SCIENCE AND TECHNOLOGY PAYLOADS RFI A Questions and Answers (Q&A) document for the Lunar Science and Technology Payloads for Expanded Lunar Landing Opportunities Request for Information (RFI) has been posted on the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES). To see the Q&A document and the full RFI text, please visit: https://go.nasa.gov/ploadsrfi Responses to the RFI are still due 11:59 PM Eastern Time on April 23, 2026. Additional questions may be emailed to the RFI's points of contact Drs. Zachary Pirtle and Brad Bailey at the shared address HQ-RFILunarPayloads@mail.nasa.gov. Please use "PLoads RFI" in the subject line of an inquiry email. Do not use this email address for RFI submissions because emailed submissions will not be considered. 12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12-12 [NASA] ROSES-25 AMENDMENT 52: NASA SMD GRADUATE STUDENT RESEARCH SOLICITATION - FUTURE INVESTIGATORS IN NASA EARTH AND SPACE SCIENCE AND TECHNOLOGY Future Investigators in NASA Earth and Space Science and Technology (FINESST) F.5 of ROSES-25 solicits proposals from accredited U.S. universities and other eligible organizations for graduate student-designed and performed research projects that contribute to SMD's science, technology, and exploration goals. The Future Investigator, i.e., the student, shall have the primary initiative to define the proposed FINESST research project and must be the primary author, with input or supervision from the proposal's Principal Investigator, as appropriate. ROSES-2025 Amendment 52 releases final text and due dates for Future Investigators in NASA Earth and Space Science and Technology (FINESST) F.5 of ROSES-25, which was previously TBD. For more information, please visit: https://go.nasa.gov/FINESST25. Neither a notice of intent nor a Step-1 proposal should be submitted. Proposals are due July 14, 2026. Questions concerning F.5 FINESST may be directed to HQ-FINESST@mail.nasa.gov. [Edited for length] 13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13-13 [NASA] CALL FOR REVIEWERS: NASA SPACE GRANT - AI WORKFORCE DEVELOPMENT NASA Research and Education Support Services (NRESS) is seeking peer reviewers for the NASA Space Grant Augmentation for AI Workforce Development opportunity. Proposal requirements and evaluation criteria are available in NSPIRES at: https://tinyurl.com/y7aw69z3 Peer review is a critical part of NASA's selection process. Reviewers with diverse backgrounds and expertise help identify high-quality projects. The peer review process is completed in two stages: Stage 1: Online individual review, currently scheduled for May 22 - June 1, 2026. Note: Mandatory training for selected online reviewers will be held on May 20, 2026. Stage 2: Virtual Panel Review, currently scheduled for June 8-11, 2026. Note: Mandatory training for selected virtual panelists will be held on June 4, 2026. If you are interested in participating, please complete the interest form by April 24, 2026: https://tinyurl.com/2uknc7vf Submitting your interest does not guarantee selection. Reviewers will be chosen based on the subject matter of proposals received. If selected, you will receive an email with detailed instructions. Inquiries should be submitted via email to SpaceGrant@nasaprs.com [Edited for length] 14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14-14 PLANETARY MEETING CALENDAR ADDITIONS Note: Many face-to-face meetings going forward will have online components. Check their websites for details. Posted at https://planetarynews.org/meetings.html October 25-30, 2026 AAS Division for Planetary Sciences Conference https://aas.org/meetings/dps58 Spokane, WA 15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15-15 PLANETARY SCIENCE JOURNAL - NEW PAPERS Direct Links to Open Access Papers Editor, Brian Jackson https://psj.aas.org The Evolution in Coma Molecular Composition of Comet C/2017 K2 (PanSTARRS) across the H2O Sublimation Zone: ALMA Imaging of a H2O-dominated Coma Nathan X. Roth et al. 2026 PSJ 7:74 https://doi.org/10.3847/PSJ/ae4d40 Constraints on Paleohydrological Activities on Mars Derived from Delta Formation Yaowen Luo et al. 2026 PSJ 7:77 https://doi.org/10.3847/PSJ/ae53dd Morphometric Properties of the CP-21 Landing Site on the Moon at Mons Gruithuisen Gamma Jean-Pierre Williams et al. 2026 PSJ 7:78 https://doi.org/10.3847/PSJ/ae523b Carbon Cycle Imbalances on Arid Terrestrial Planets with Implications for Venus Haskelle T. White-Gianella and Joshua Krissansen-Totton 2026 PSJ 7:79 https://doi.org/10.3847/PSJ/ae4faa The Population of Craters that Host Permanently Shadowed Regions Near the Lunar South Pole: Implications for Typical Cold-trap Lifetimes Caleb I. Fassett et al. 2026 PSJ 7:80 https://doi.org/10.3847/PSJ/ae5526 The Effects of Propane on Nitrogen-Hydrocarbon Mixtures Relevant to Titan's Lakes and Seas Cecilia Thieberger et al. 2026 PSJ 7:81 https://doi.org/10.3847/PSJ/ae4fb3 16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16-16 JOURNAL OF GEOPHYSICAL RESEARCH: PLANETS - NEW PAPERS Direct Links to Open Access (OA) Papers Editors-in-Chief, Amanda Hendrix & Debra Buczkowski https://agupubs.onlinelibrary.wiley.com/journal/21699100 https://doi.org/10.1029/2025JE009447 New Climatology of Martian Water Vapor Column Abundance Derived From NOMAD LNO Nadir Observations Over Martian Years 34-38 F. Hendrick et al. https://doi.org/10.1029/2025JE009592 Characterization of the Outer Uranian Rings in the Visual and Near-IR Using Keck, JWST, and HST Observations Imke de Pater et al. https://doi.org/10.1029/2025JE009404 Amapari Marker Band Metal-Enrichments: Potential Mechanisms and Implications for Surface and Subsurface Water and Weathering in Gale Crater P. J. Gasda et al. https://doi.org/10.1029/2025JE009153 Strong Variability of the Modeled Venus NO Nightglow N. Streel et al. https://doi.org/10.1029/2025JE009316 *********************************************************************** * The Planetary Exploration Newsletter is issued approximately weekly. * Current and back issues are available at https://planetarynews.org * * To subscribe, go to https://planetarynews.org and click on Subscribe. * * An unsubscribe option is available at the end of every PEN email. Or * send an email to pen_editor@psi.edu * * Please send all replies and submissions to pen_editor@psi.edu. * Announcements and other messages should be brief with links to URLs * for extended information, including detailed descriptions for job * announcements. Title plus text is limited to 200 words. Go to * https://planetarynews.org/submission.html for complete submission * directions. * * PEN is a service provided by the Planetary Science Institute * (https://www.psi.edu) using no NASA funds. All editorial work is * volunteer. ***********************************************************************