Z=0 No Z Z- NON. Solar System Theory and Observa3ons

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1 Solar System Theory and Observa3ons Stefanie Milam JWST Deputy Project Scientist for Planetary Science NASA Goddard Space Flight Center Z=0 No Z Z- NON ATLAS Workshop: Massively Parallel Large Area Spectroscopy from Space

2 Solar System Science with Astrophysics Missions HST News Circulation - Calendar 2013 (Source: Meltwater News) Circulation in millions 2.3% 15.4% Fomalhaut planet orbit brown dwarf atm. Heritage M106 galaxy strobing protostarstar MW halo stars' motion Heritage: space invader oldest nearby star LMC X-ray source farthest supernova Horsehead nebula/anniversary comet ISON Hyades WD planet debris Ring nebula structure Proxima Cen. planned obs. T-Pyx nova TW Hydrae planetary gap Heritage Arp 142 comet ISON movie blue exoplanet Neptune moon Heritage: comet ISON GRB Kilonova Magellanic stream origin Galaxies in time M87 black hole jet movie Heritage "caterpillar" nebula ESA - planetary neb. Alignment Huge Globular Cluster population Water laden asteroids comet ISON Heritage Farthest galaxy (UTX co-release) Frontier Fields active asteroid Milky Wat evolution water on exoplanets Europa Plumes 7-Jan8-Jan5-Feb 7-Feb 21-Feb 5-Mar 7-Mar 4-Apr 4-Apr 19-Apr 23-Apr 9-May 23-May 3-Jun4-Jun 13-Jun 20-Jun 2-Jul 11-Jul 15-Jul 25-Jul 3-Aug 8-Aug 15-Aug 22-Aug 29-Aug 2-Sep 12-Sep 10-Oct 17-Oct 23-Oct 24-Oct 7-Nov 14-Nov 2-Dec 12-Dec

3 ATLAS and the Solar System ATLAS Science Objec-ve 4, "Probe the forma-on history of the outer Solar System through the composi-on of 3,000 comets and asteroids," flows down to a Solar System Survey with 3000 individual poin-ngs, covering a total area of 1,200 sq deg. ATLAS can provide valuable insight into the proper-es and composi-on of Solar System objects from comets and asteroids to Trans- Neptunian objects. ATLAS Solar System Survey will focus on the likle explored Kuiper Belt Objects.

4 Small Bodies in the Solar System

5 The Outer Solar System Kuiper Belt Objects (KBOs) Trans- Neptunian Objects (TNOs) T ~ 50 K à NIR will not probe thermal emission. Determining albedo and diameter will need other facili-es

6 The KBO popula3on as we know it D<500 km KBOs which dominate the mass of the popula-on Only features iden-fied in the IR spectra of small KBOs are absorp-on features: ü water- ice (1.5μm and 2.0μm) ü methane ü methanol Not able to iden-fy the silicate components in KBOs even from New Horizons Lack of iden-fying absorp-on features in the λ~2.5micron, the current wavelength limit beyond which telescopes lack sufficient sensi-vity to gather quality spectra for the majority of KBOs [ALL SMALL BODIES]. Wang et al and references therein

7 Pluto from New Horizons Flyby

8 Pluto from VLT Protoppa et al. 2008

9 TNOs in the Era of JWST Obtain full NIR spectra of larger TNOs and characterize them. Photometry (NIRCam) of smaller objects. Composi-onal studies of every known target 100 km in a reasonable amount of observing -me. Simulated Centaur (D~80km at 22AU) JWST NIRSpec R~1000 Parker et al. 2016

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11 WFIRST Surveys and small body detec-ons KBO detec3ons in WFIRST surveys WFIRST will reach r~27 (diameter of ~20 km)** with each set of exposures in a par-cular filter during the HLS survey (KNOWN KBOs) ~2.5 mag fainter (10 -mes lower flux) than the DES and LSST surveys Serendipitous discovery of NEW KBOs is dependent on cadence detec-on is possible at ~1 day increments. Observa-ons with mul-ple filters will result in near- infrared spectral slopes that provide a first- order HLS look at composi-onal differences. detec-on of new minor bodies with the HLS could probe an interes-ng subset of the color phase space of the <150 km objects SNe Holler et al **Assuming a heliocentric distance of 40 AU, an observer distance of 39 AU, a geometric albedo of 0.08, an average g- r color for KBOs of 0.65, and using the SDSS to Johnson filter conversions from R. Lupton*

12 Where are they? KBOs have a complex and finely structured popula-on distribu-on, with the majority of the popula-on in low- inclina-on, low- eccentricity orbits Ø near the eclip-c Ø density of KBOs decreases rapidly further from the eclip-c. However, there are excep-ons ʻOumuamua

13 ATLAS Solar System Survey and ATLAS Wide Pointed survey of ~3000 KBOs (iden-fied from previous surveys) 2500s integra-ons for SNR~10 sensi-vity of OH feature at 3 microns No tracking required Rates ~1-4 /hr Sequence slits as targets move 1000s integra-ons? ATLAS Wide will detect >250 targets Wang et al. 2018

14 Asteroids the other small bodies Surveys to serendipitously detect asteroids will depend on loca-on most are VERY close to the Eclip-c. However access to the NIR that is not accessible from the ground is interes-ng see Rivkin et al micron would be useful for all targets Ceres Spectrum from IRTF R~200 <2micron, R~3000 >2.3 micron Ceres from IRTF Holler et al From Rivkin, personal communica-on

15 Characterizing Asteroids with ATLAS Challenging, but do- able for brighter targets Will take ~2 min for average asteroid to cross slit Can bin to lower resolu-on to enhance sensi-vity The micron range is s-ll appealing even for bright targets Will complement WFIRST and ground- based surveys (e.g. LSST)

16 Moving Targets MOVE Milam et al. 2016

17 MT Tracking As a spectroscopic mission, the implica-ons for MT tracking are significant. Access to more of the Solar System Dynamic Objects that always need observa-ons New Science enabled!!! Coupled with dynamic range. Blurring of the flux contained within one WFIRST WFI pixel (0.11 / pixel) in one detector readout -me (2.7 seconds) for the cases of no moving target tracking and moving target tracking of up to 30 mas/s. Holler et al. 2018

18 Other Solar System Science? Satellite characteriza-on and monitoring Plumes, volcanos, weather (Titan) Planetary atmospheres (???) Weather, seasonal varia-on, impact events Rings Composi-on, new rings Comets Composi-on of new objects (comae, tails, etc) E.g., see PASP special issue on Solar System Science with JWST.

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20 Summary Solar System science enabled by space telescopes is compelling to not only the science community, but also the public. Spectroscopic survey capability will reveal new insights into the composi-on of small bodies and help constrain theories of solar system forma-on/evolu-on. MT tracking enables addi-onal science for the solar system. ATLAS will be a significant complementary resource to current/ future survey assets.

21 Questions? 22