Rosetta at Comet 67P/Churyumov-Gerasimenko: Landing and Archiving Data

NASA SBAG Report

Bonnie Buratti, US Rosetta Project Scientist, JPL Arthur B. Chmielewski US Rosetta Project Manager, JPL

Mathieu Choukroun, US RosettaDeputy Project Scientist, JPL

January 11, 2017

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Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI.

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The US Contribution to Rosetta 1. 3 ½ instruments 2. 3 PI’s, PS, DPS, IDS 3. 46 Co-I’s and researchers 4. DSN 70 m and 34 m support 5. ASPEN scheduling software for science observations 6. SPICE support 7. Comet modeling 8. Shadow navigation for flight dynamics verification 9. Outreach and media products 10. Leadership for ESA's Amateur Ground Observing

Campaign

Instrument Purpose Country of Origin Alice Ultraviolet spectrometer United States CONSERT Radar tomography France COSIMA Dust composition Germany GIADA Dust detector Italy MIDAS Atomic Force Microscope Austria MIRO Microwave spectrometer/radiometer United States OSIRIS Narrow-angle and wide-angle cameras Germany ROSINA Gas composition Switzerland RPC Magnetometer, plasma detectors Various, inc. US RSI Radio science investigation Germany VIRTIS Infrared spectrometer Italy

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Escorting the comet

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August 2014

Credit: NASA/JPL Caltech

Rosetta.jpl.nasa.gov

Sept 2016 – Landing!

National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Outreach activities late 2016 • Claudia Alexander was a tireless proponent of outreach, and we have tried to continue on that

path • Public lecture (von Karman series) on August 11 and 12 by Project Manager and Project Scientist;

600 participants plus thousands of streaming viewers • An Educators’ Workshop at JPL was held on Sept. 24, 2016 with about 40 teachers attending. The

full day event included lectures on small bodies and Rosetta, plus hands-on activities such as “kitchen comets”.

• Partnership with Chinle (Arizona) school district for month-long science program in June; 20-30 students from Navajo Nation participate

• Sept. 30: Friends & Family program prior to “landing” leading into NASA TV live from Darmstadt and into ESA feed. Don Yeomans was M. C.

• Popular NASA Rosetta Blog written by co-Is • NASA TV and interview events associated with landing on Sept. 30, 2016 • Outreach events planned for the Science Working Team Meeting #47 in New York City, reaching

an underserved cohort

prox Ekaterina Smirnova Space Artist

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Ekaterina Smirnova, Rosetta’s artist, presented a show on Rosetta during DPS, gave a talk at JPL on Oct. 24, and is invited to talk in New York.

U.S. Rosetta Project National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology JPL/Caltech Proprietary – Not for Public Release

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Philae found Sept 5, 2016

U.S. Rosetta Project National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology JPL/Caltech Proprietary – Not for Public Release

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Rosetta End-of-Mission: Landing on 67P • Targeted impact region just beside

one large pit of the Ma’at region. • Most instruments “ON” until the

end.

Ma’at pit “D” Impact site

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Sept 2, 2016 Sept 5, 2016

Check out: https://planetgate.mps.mpg.de/Image_of_the_Day/public/IofD_archive.html

Approx. FOV: 171 M 157 M

U.S. Rosetta Project National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology JPL/Caltech Proprietary – Not for Public Release

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Final images before landing: 5.8 km and ~ 25 meters

FOV 223 m FOV 96 cm

U.S. Rosetta Project National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology JPL/Caltech Proprietary – Not for Public Release

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Last data from NASA Instruments on Rosetta

Shaded cliff of Ma’at pit D

MIRO: last 1 h of subsurface temperature Alice: last UV spectrum 8 min before impact

Data packet obtained in last 1 minute before impact

Rosetta’s descent provided a wealth of high-resolution data, which will be invaluable to understand the influence of small-scale features on the surface of 67P on the data obtained by MIRO and Alice.

Courtesy: F. Peter Schloerb

Courtesy: Joel Parker

Top 10 discoveries of Rosetta (with US contributions) 1. Comet 67P/ Churyumov-Gerasimenko is primitive and relatively unprocessed, except in its very shallow subsurface (upper

few meters). Partly MIRO (Microwave Imager for Rosetta), built at JPL.

2. Molecular hydrogen, oxygen, and nitrogen were discovered, and they were incorporated at the comet from the beginning, showing that the comet formed in a low-temperature environment. US co-Is on ROSINA, the Rosetta Mass Spectrometer

3. The ratio of deuterium to hydrogen in the water from the comet was determined to be three times that found for terrestrial water, showing that the D/H ratio in water from Jupiter-Family comets vary widely. This suggests possible multiple reservoirs, or a more complex D/H distribution in the solar nebula than previously thought. US co-Is on ROSINA.

4. The nucleus is far more complicated than envisioned: the comet is nearly binary, composed of two planetesimals. There are pits (former outgassing sites), cliffs, layers, “goose bumps”, “dinosaur eggs”, and boulders. The comet’s jets originate mostly from cliffs and pit walls. One Imaging Team Member (Bjorn Davidsson) now at JPL.

5. The density of the comet is low, about 0.5 gm/cc. The upper ~20 cm is tenuous, covering a harder, more compact layer. Further into the comet, the density decreases. (MIRO data and partly DSN data; US IDS Weissman on Radio Science Team)

6. The comet’s nucleus has no magnetic field. US co-Is on Magnetometer team.

7. Most of the outgassing of water takes place at the neck region because of shape and orientation (MIRO).

8. Organic molecules, including the amino acid glycine, were detected on the comet. . US co-Is on ROSINA.

9. Diamagnetic cavities were found in the vicinity of the comet (Electrons detected by the Ion Electron Spectrometer from SWRI helped map them; US co-Is on Magnetometer team).

10. Electrons, rather than solar photons, are responsible for the rapid breakup of water and CO2 (Alice – UV spectrometer built at SWRI - discovery)

11. (Bonus) The comet is dusty, with a dust to gas ratio of ~4:1 near perihelion

Wild-2 (Stardust)

Tempel-1 (Deep Impact)

2104 MU 69 New Horizons KBO target 2019 ~45 km radius (this is Pandora)

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Comets above KBOs (increasing size)

Phoebe Cassini flyby Captured KBO Battered, dense (1.6 gm/cc) Undifferentiated 107 km radius

Charon New Horizons Global melting Differentiated (?) 606 km radius

Pluto New Horizons Largest known KBO Differentiated Active geology 1187 km radius

Comet 67P/ Churyumov-Gerasimenko in context: Characterizing both comets and Kuiper Belt Objects (KBOs) 67/P Primitive Smallest KBO observed 3.1 km radius

National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Rosetta Data Analysis Program (RDAP)

• The intent of the Rosetta Data Analysis Program is to provide the funding that will allow for continued analysis and interpretation of data, provide the opportunity for new collaborations and investigators, and support limited laboratory and field measurements (including astronomical data) to interpret space measurements correctly. Synergistic analyses will be encouraged, including comparisons with data from other missions

• Can propose analysis of PDS data that is available at time of issue • Typically $100-200K/year/3 years award levels • Collaborations with European PIs encouraged (no funding to

international investigations) • Headquarters assurance that RDAP will occur

Recent and upcoming significant events

• AGU Fall Meeting 2016 special session: 8 oral talks and 22 poster talks • US co-I meeting at AGU Dec. 11: over 30 participants and talks • US Rosetta Scientific Working Team (SWT #47) meeting in the US in 2017

– first ever. Location is New York City, March 14-17, 2017 • March 2017 co-I meeting will be combined with SWT #47 • Archiving into PDS and ESA’s Planetary Science Archive (PSA) proceeding

on schedule. Level 3 and 4 products are being emphasized. Some concern as end-of-Project for NASA is March 31, 2018, while ESA will continue until the end of 2019. Delta-review in early 2018 may be required.

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The US Rosetta Project would like to thank: • ESA for the fabulous ride • NASA HQ - Jim Green, Tony Carro and David Schurr for

steadfast support over the years