arXiv subjects

Josh Emery

Publications and source records attributed to Josh Emery.

5 recordsLinked to original sources

arXiv2026

Hydration Features on Near-Earth Objects: Integrating New Data with Prior Results

Near-Earth objects (NEOs) are excellent laboratories for testing processes that affect airless bodies, as well as informing us about Solar System history. Though most NEOs are nominally anhydrous because they formed inside the Solar System frost line and their surface temperatures are high enough to remove volatiles, a 3-micron feature typically indicative of OH/H2O has been identified on several such bodies. Possible sources for OH/H2O on these bodies include carbonaceous chondrite impactors or interactions with protons implanted by solar wind. The MIT-Hawaii Near-Earth Object Spectroscopic Survey (MITHNEOS) began its 3-micron observation campaign of NEOs in 2022 and has obtained spectral data of 15 predominantly nominally anhydrous (i.e., mostly S-complex or V-type) targets using NASA's Infrared Telescope Facility's (IRTF) near-infrared spectrometer, SpeX. Spectra were collected using both prism (0.7-2.52 micron) and LXD_short (1.67-4.2 micron) modes to accurately characterize asteroid spectral type and the 3-micron region. Four of the 15 NEOs observed exhibit a 3-micron feature, exhibiting band shapes similar to those identified in a previous NEO survey (McGraw et al. 2022), which found a trend between hydration band presence and large aphelion (i.e., Q > 2.06 AU). Combining our new observations with the pre-existing database of NEO 2-4-micron data revealed that band depth increases with decreasing orbital inclination and that all NEOs with hydration bands have i < 27 degrees with most having i < 14 degrees. We find that NEOs with low inclination and large aphelia are the most likely bodies in near-Earth space to possess surficial OH/H2O.

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arXiv2024

Size-Based Spectrophotometric Analysis of the Polana-Eulalia Complex

The Polana-Eulalia Complex (PEC) is an Inner Main Belt, C-complex asteroid population that may be the source of the near-Earth asteroid spacecraft mission targets (101955) Bennu and (162173) Ryugu. Here, we report a size-based investigation of the visible (VIS; 0.47 -- 0.89 um) spectrophotometric slopes of the PEC's constituent families, the New Polana and Eulalia Families. Using two releases of the Sloan Digital Sky Survey's Moving Object Catalog as well as the 3rd data release of the Gaia catalog, we present evidence of size-based slope variability within each family. We find that Eulalia family members exhibit lower average slopes than Polana family members in all catalogs' samples, particularly for objects < 9 km in diameter. We are unable to conclude that VIS slope distinguishability between the families is statistically significant, but we explore a potential cause of the bulk slope differences between the PEC families, in addition to providing commentary on size-slope trends generally.

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arXiv2020

Spitzer's Solar System Science Legacy: Studies of the Relics of Solar System Formation & Evolution. Part 1 - Comets, Centaurs, & Kuiper Belt Objects

In its 16 years of scientific measurements, the Spitzer Space Telescope performed a number of ground breaking and key infrared measurements of Solar System objects near and far. Targets ranged from the smallest planetesimals to the giant planets, and have helped us reform our understanding of these objects while also laying the groundwork for future infrared space-based observations like those to be undertaken by the James Webb Space Telescope in the 2020s. In this first Paper, we describe how the Spitzer Space Telescope advanced our knowledge of Solar System formation and evolution via observations of small outer Solar System planetesimals, i.e., Comets, Centaurs, and Kuiper Belt Objects (KBOs). Relics from the early formation era of our Solar System, these objects hold important information about the processes that created them. The key Spitzer observations can be grouped into 3 broad classes: characterization of new Solar System objects (comets D/ISON 2012 S1, C/2016 R2, 1I/`Oumuamua); large population surveys of known object sizes (comets, Centaurs, and KBOs); and compositional studies via spectral measurements of body surfaces and emitted materials (comets, Centaurs, and KBOs).

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arXiv2014

The Design Reference Asteroid for the OSIRIS-REx Mission Target (101955) Bennu

The Design Reference Asteroid (DRA) is a compilation of all that is known about the OSIRIS-REx mission target, asteroid (101955) Bennu. It contains our best knowledge of the properties of Bennu based on an extensive observational campaign that began shortly after its discovery, and has been used to inform mission plan development and flight system design. The DRA will also be compared with post-encounter science results to determine the accuracy of our Earth-based characterization efforts. The extensive observations of Bennu in 1999 has made it one of the best-characterized near-Earth asteroids. Many physical parameters are well determined, and span a number of categories: Orbital, Bulk, Rotational, Radar, Photometric, Spectroscopic, Thermal, Surface Analog, and Environment Properties. Some results described in the DRA have been published in peer-reviewed journals while others have been reviewed by OSIRIS-REx Science Team members and/or external reviewers. Some data, such as Surface Analog Properties, are based on our best knowledge of asteroid surfaces, in particular those of asteroids Eros and Itokawa. This public release of the OSIRIS-REx Design Reference Asteroid is a annotated version of the internal OSIRIS-REx document OREX-DOCS-04.00-00002, Rev 9 (accepted by the OSIRIS-REx project on 2014-April-14). The supplemental data products that accompany the official OSIRIS-REx version of the DRA are not included in this release. We are making this document available as a service to future mission planners in the hope that it will inform their efforts.

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arXiv2007

Planetary Science Goals for the Spitzer Warm Era

The overarching goal of planetary astronomy is to deduce how the present collection of objects found in our Solar System were formed from the original material present in the proto-solar nebula. As over two hundred exo-planetary systems are now known, and multitudes more are expected, the Solar System represents the closest and best system which we can study, and the only one in which we can clearly resolve individual bodies other than planets. In this White Paper we demonstrate how to use Spitzer Space Telescope InfraRed Array Camera Channels 1 and 2 (3.6 and 4.5 um) imaging photometry with large dedicated surveys to advance our knowledge of Solar System formation and evolution. There are a number of vital, key projects to be pursued using dedicated large programs that have not been pursued during the five years of Spitzer cold operations. We present a number of the largest and most important projects here; more will certainly be proposed once the warm era has begun, including important observations of newly discovered objects.

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