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Carey M Lisse

Johns Hopkins University, Applied Physics Laboratory, Prinicpal investigator Scientific

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Dr. Carey Lisse has over 36 years of experience in experimental and observational research that includes astrophysics, detector physics, chemical physics, optics, electronics, and remote sensing data analysis. At JHU-APL, he is involved with studying the physical properties of primitive solar system objects; the rock-forming dust contained in comets, the IPD cloud, the Proto-Solar Nebula, and YSOs; x-ray emission from solar system bodies and the heliosphere; and designing, building, and operating Solar System spacecraft missions. (See CV for more details.)

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Papers by Carey M Lisse

29P/Schwassmann-Wachmann: A Rosetta Stone for Amorphous Water Ice and CO <-> CO2 Conversion in Centaurs and Comets?

arXiv (Cornell University), Sep 19, 2022

Centaur 29P/Schwassmann-Wachmann 1 (SW1) is a highly active object orbiting in the transitional "... more Centaur 29P/Schwassmann-Wachmann 1 (SW1) is a highly active object orbiting in the transitional "Gateway" region between the Centaur and Jupiter Family Comet regions. SW1 is unique among the Centaurs in that it experiences quasi-regular major outbursts and produces CO emission continuously; however, the source of the CO is unclear. We argue that due to its very large size (~32 km radius), SW1 is likely still responding, via amorphous water ice (AWI) conversion to crystalline water ice (CWI), to the "sudden" change in its external thermal environment produced by its dynamical migration from the Kuiper belt to the Gateway Region at the inner edge of the Centaur region at 6 au. It is this conversion process that is the source of the abundant CO and dust released from the object during its quiescent and outburst phases. If correct, these arguments have a number of important predictions testable via remote sensing and in situ spacecraft characterization, including: the quick release on Myr timescales of CO from AWI conversion for any few km-scale scattered disk KBO transiting into the inner system; that to date SW1 has only converted between 50 to 65% of its nuclear AWI to CWI; that volume changes upon AWI conversion could have caused subsidence and cave-ins, but not significant mass wasting or crater loss; that SW1's coma should contain abundant amounts of CWI CO2-rich "dust" particles; and that when SW1 transits into the inner system within the next 10,000 years, it will be a very different kind of JFC comet.

Accepted for Publictation in the Astronomical Journal Infrared Spectroscopy of Comet 73P/Schwassmann-Wachmann 3 using the Spitzer Space Telescope

We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 µm therm... more We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 µm thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R∼100) data over the entire wavelength interval, along with images at 16 and 22 µm. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet-cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, ∼35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggests that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. The best-fit particle size distribution for SW3B has a form dn/da∼a −3.5 , close to that expected for dust in collisional equilibrium, while that for SW3C has dn/da∼a −4.0 , as seen mostly in active comets with strong directed jets such as C/1995 O1 Hale-Bopp. The total mass of dust in the comae plus nearby tail, extrapolated from to the field of view of the IRS peakup image arrays, is 3-5 x 10 8 kg for B and 7-9 x 10 8

Dust from collisions: A way to probe the composition of exo-planets?

In order to link infrared observations of dust formed during planet formation in debris disks to ... more In order to link infrared observations of dust formed during planet formation in debris disks to mid-infrared spectroscopic data of planetary materials from differentiated terrestrial and asteroidal bodies, we obtained absorption spectra of a representative suite of terrestrial crustal and mantle materials, and of typical Martian meteorites. A series of debris disk spectra characterized by a strong feature in the 9.0-9.5 µm range (HD23514, HD15407a, HD172555 and HD165014), is comparable to materials that underwent shock, collision or high temperature events. These are amorphous materials such as tektites, SiO2-glass, obsidian, and highly shocked shergottites as well as inclusions from mesosiderites (Group A). A second group (BD+20307,

Invited Article: Deep Impact instrument calibration

Review of Scientific Instruments, 2008

Calibration of NASA’s Deep Impact spacecraft instruments allows reliable scientific interpretatio... more Calibration of NASA’s Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [∼1.7pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of ∼9pixels. The charge coupled device (CCD) read noise is ∼1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is ...

Mid-infrared spectra of differentiated meteorites (achondrites): Comparison with astronomical observations of dust in protoplanetary and debris disks

Icarus, 2012

Mid-infrared (5 m to 25 m) transmission/absorption spectra of differentiated meteorites (achond... more Mid-infrared (5 m to 25 m) transmission/absorption spectra of differentiated meteorites (achondrites) were measured to permit comparison with astronomical observations of dust in different stages of evolution of young stellar objects. In contrast to primitive chondrites, achondrites underwent heavy metamorphism and/or extensive melting and represent more advanced stages of planetesimal evolution. Spectra were obtained from primitive achondrites (acapulcoite, winonaite, ureilite, and brachinite) and differentiated achondrites (eucrite, diogenite, aubrite, and mesosiderite silicates). The ureilite and brachinite show spectra dominated by olivine features, and the diogenite and aubrite by pyroxene features. The acapulcoite, winonaite, eucrite, and mesosiderite silicates exhibit more complex spectra, reflecting their multi-phase bulk mineralogy. Mixtures of spectra of the primitive achondrites and differentiated achondrites in various proportions show good similarities to the spectra of the few Myr old protoplanetary disks HD104237A and V410 Anon 13. A spectrum of the differentiated mesosiderite silicates is similar to the spectra of the mature debris disks HD172555 and HD165014. A mixture of spectra of the primitive ureilite and brachinite is similar to the spectrum of the debris disk HD113766. The results raise the possibility that materials produced in the early stage of planetesimal differentiation occur in the protoplanetary and debris disks.

Mid-infrared spectroscopy of components in chondrites: Search for processed materials in young Solar Systems and comets

Icarus, 2014

We obtained mid-infrared spectra of chondrules, matrix, CAIs and bulk material from primitive typ... more We obtained mid-infrared spectra of chondrules, matrix, CAIs and bulk material from primitive type 1-4 chondrites in order to compare them with the dust material in young, forming solar systems and around comets. Our aim is to investigate whether there are similarities between the first processed materials in our early Solar System and protoplanetary disks currently forming around other stars. Chondrule spectra can be divided into two groups. 1) Chondrules dominated by olivine features at ~11.3 µm and ~10.0 µm. 2) mesostasis rich chondrules that show main features at ~10 µm. Bulk ordinary chondrites show similar features to both groups. Fine-grained matrix is divided into three groups. 1) phyllosilicate-rich with a main band at ~10µm, 2) olivine-rich with bands at 11.3 µm and ~10 µm, 3) pyroxene-rich with several peaks between 9.3 µm and 11.2 µm. Impact shock processed matrix from Murchison (CM2) shows features from phyllosilicaterich, amorphous and olivine-rich material. CAIs show melilite/spinel-rich features between 10.2 µm and 12.5 µm. Astronomical spectra are divided into four groups based on their spectral characteristics-amorphous (group 1), pyroxene-rich (group 2), olivine-rich (group 3) and 'complex' (group 4). Group 2 is similar to enstatite-rich fine grained material like e.g. Kakangari (K3) matrix. Group 3 and 4 can be explained by a combination of varying concentrations of olivine and mesostasis-rich chondrules and fine-grained matrix, but also show very good agreement with shock processed material. Comparison of band ratios confirms the similarity with chondritic material e.g. for HD100546, while the inner disk of HD142527 show no sign of chondrule material. Comparison between the laboratory infrared-red IR data and astronomical spectra indicate a general similarity between primitive solar system materials and circumstellar dust and comets, especially in the inner disks of young solar systems. However, other amorphous materials like IDP/GEMS have to be taken into account.

Kuiper Belt object 2014MU69, Pluto and Phoebe as windows on the composition of the early solar nebula

Proceedings of the International Astronomical Union, 2019

The initial chemical composition of a proto-planetary nebula depends upon the degree to which 1) ... more The initial chemical composition of a proto-planetary nebula depends upon the degree to which 1) organic and ice components form on dust grains, 2) organic and molecular species form in the gas phase, 3) organics and ices are exchanged between the gas and solid state, and 4) the precursor and newly formed (more complex) materials survive and are modified in the developing planetary system. Infrared and radio observations of star-forming regions reveal that complex chemistry occurs on icy grains, often before stars even form. Additional processing, through the proto-planetary disk (PPD) further modifies most, but not all, of the initial materials. In fact, the modern Solar System still carries a fraction of its interstellar inheritance (Alexander et al.2017). Here we focus on three examples of small bodies in our Solar System, each containing chemical and dynamical clues to its origin and evolution: the small-cold classical Kuiper Belt object (KBO) 2014 MU69, Pluto, and Saturn’s moon...

Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis Ofwise/Neowiseobservations

The Astrophysical Journal, 2013

The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (S... more The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (SDOs) in the thermal infrared, including 15 new discoveries. We present analyses of these observations to estimate sizes and mean optical albedos. We find mean albedos of 0.08 ± 0.04 for the entire data set. Thermal fits yield average beaming parameters of 0.9 ± 0.2 that are similar for both SDO and Centaur sub-classes. Biased cumulative size distributions yield size-frequency distribution power law indices of ∼−1.7 ± 0.3. The data also reveal a relation between albedo and color at the 3σ level. No significant relation between diameter and albedos is found.

The temperature, thermal inertia, roughness and color of the nuclei of Comets 103P/Hartley 2 and 9P/Tempel 1

Icarus, 2013

The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on November 4th, 2010 (EPOXI mission) and... more The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on November 4th, 2010 (EPOXI mission) and Comet 9P/Tempel 1 on July 4th, 2005 (Deep Impact mission). During the two flybys, spatially resolved infrared (1.05-4.8 lm) spectra of the surface of the nucleus were acquired by the HRI-IR instrument. The analysis of these two data sets, obtained by the same instrument, offers a unique opportunity to understand, compare and contrast the surface thermal properties of these two comets. For this paper, we use spectral cubes with a spatial resolution of 30 m/pixel to 40 m/pixel for Hartley 2 and 160 m/pixel for Tempel 1. We focus our analysis on the color, temperature, thermal inertia and roughness of the nucleus. The two comets have the same color, moderately red, with an average slope of 3.0 ± 0.9% per kÅ to 3.5 ± 1.1% per kÅ. There are very small variations of the color across the surface, except for regions with water ice that are neutral to blue, and two dark spots with redder (4.5 ± 1.4% per kÅ) materials on Hartley 2. The nucleus thermal emission at all resolved spatial scales differs from that of a gray body with an infrared emissivity of 0.9-1.0, the discrepancy being more important for larger incidence angles. Moreover, the color temperature of Comets Hartley 2 and Tempel 1 is relatively homogeneous across the surface and does not vary strongly with incidence angle. These two effects mainly result from surface roughness and associated projected shadows. From the temperature rise on the morning terminator, we derive a thermal inertia lower than 250 W/K/m 2 /s 1/2 for Hartley 2 and lower than 45 W/K/m 2 /s 1/2 for Tempel 1 (3r upper limits). For Hartley 2 and Tempel 1, the temperature of the regions with exposed water ice is more than 100 K above the sublimation temperature of water ice ($200 K). This observation indicates that the thermal emission is dominated by dust, and that water ice is not intimately mixed with dust at the scale of observation, with water ice patches at the meter or sub-meter scale.

Astrophysics with New Horizons: Making the Most of a Generational Opportunity

Publications of the Astronomical Society of the Pacific, 2018

The outer solar system provides a unique, quiet vantage point from which to observe the universe ... more The outer solar system provides a unique, quiet vantage point from which to observe the universe around us, where measurements could enable several niche astrophysical science cases that are too difficult to perform near Earth. NASA's New Horizons mission comprises an instrument package that provides imaging capability from ultraviolet (UV) to near-infrared (near-IR) wavelengths with moderate spectral resolution located beyond the orbit of Pluto. A carefully designed survey with New Horizons can optimize the use of expendable propellant and the limited data telemetry bandwidth to allow several measurements, including a detailed understanding of the cosmic extragalactic background light; studies of the local and extragalactic UV background; measurements of the properties of dust and ice in the outer solar system; confirmation and characterization of transiting exoplanets; determinations of the mass of dark objects using gravitational microlensing; and rapid follow-up of transient events. New Horizons is currently in an extended mission designed to focus on Kuiper Belt science that will conclude in 2021. The astrophysics community has a unique, generational opportunity to use this mission for astronomical observation at heliocentric distances beyond 50 au in the next decade. In this paper, we discuss the potential science cases for such an extended mission, and provide an initial assessment of the most important operational requirements and observation strategies it would require. We conclude that New Horizons is capable of transformative science, and that it would make a valuable and unique asset for astrophysical science that is unlikely to be replicated in the near future.

Thermal alteration and differential sublimation can create Phaethon's “rock comet” activity and blue color

Icarus, 2022

In 2010 Jewitt and Li published a paper examining the behavior of "comet-asteroid transition obje... more In 2010 Jewitt and Li published a paper examining the behavior of "comet-asteroid transition object" 3200 Phaethon, arguing it was asteroid-like in its behavior throughout most of its orbit, but that near its perihelion, at a distance of only 0.165 AU from the sun, its dayside temperatures would be hot enough to vaporize rock (>1000 K, Hanus et al. 2016). Thus it would act like a "rock comet" as gases produced from evaporating rock were released from the body, in a manner similar to the more familiar sublimation of water ice into vacuum seen for comets coming within ~3 AU of the Sun. In this Note we predict that the same thermal effects that would create "rock comet" behavior with Qgas ~ 10 22 mol/sec at perihelion have also helped to greatly bluen Phaethon's surface via preferential thermal alteration and sublimative removal of Fe and refractory organics, known reddening and darkening agents. These predictions are testable by searching for signs of spectral bluening of the surfaces of other small bodies in Phaethon-like small perihelion orbits, including comets, and by in situ measurements of Phaethon's surface and coma composition near perihelion with the upcoming DESTINY+ mission (Kawakatsu & Itawa 2013, Arai et al. 2018) to Phaethon by JAXA.

Spitzer’s Solar System studies of comets, centaurs and Kuiper belt objects

Nature Astronomy, 2020

Widefield camera 3 for the Hubble Space Telescope

SPIE Proceedings, 2000

In June 1997, NASA made the decision to extend the end of the Hubble Space Telescope (HST) missio... more

A Predicted Dearth of Majority Hypervolatile Ices in Oort Cloud Comets

The Planetary Science Journal

We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the... more We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the 2019 January 1 MU69/Arrokoth flyby of Gladstone et al. and use them to make predictions about the rarity of majority hypervolatile (CO, N2, CH4) ices in Kuiper Belt objects and Oort Cloud comets. These predictions have a number of important implications for the study of the Oort Cloud, including the determination of hypervolatile-rich comets as the first objects emplaced into the Oort Cloud, the measurement of CO/N2/CH4 abundance ratios in the protoplanetary disk from hypervolatile-rich comets, and population statistical constraints on early (<20 Myr) planetary aggregation driven versus later (>50 Myr) planetary migration driven emplacement of objects into the Oort Cloud. They imply that the phenomenon of ultradistant active comets like C/2017K2 should be rare, and thus not a general characteristic of all comets. They also suggest that interstellar object 2I/Borisov may not have o...

Isophot Observations of Comet Hale-Bopp: Initial Data Reduction

arXiv: Astrophysics, Dec 9, 1998

Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board the Infrared Space ... more Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board the Infrared Space Observatory (ISO). Each time broadband photometry was performed using 4 different detectors, 5 apertures and, 10 filters covering the range between 3.6 to 175 µm. Calibration measurements using the internal Fine Calibration Source were done together with each individual measurement. Background observations were performed with identical instrument settings at the same positions on the sky several days after the comet observations. The observation strategy and the initial data reduction steps are described in some detail and the resulting in-band power values of the Hale-Bopp observations and their uncertainties are derived. Initial reduction of these measurements was performed in 3 steps: (1) processing of raw data by removing instrumental and energetic particle effects, (2) averaging of the individual signals, and (3) determination of the detector responsivities and their uncertainties. The detector signal is determined by two different methods and the best value is chosen. At the present level of processing uncertainties range from 10% to a factor of 3 for the low power levels at short wavelengths. The in-band power levels at different wavelengths varied over 3 orders of magnitude.

Isophot Observations Of Comet Hale-Bopp

Comet Hale-Bopp has been observed five times with ISOPHOT, the photometer on board the Infrared S... more Comet Hale-Bopp has been observed five times with ISOPHOT, the photometer on board the Infrared Space Observatory (ISO), four times before its perihelion passage at heliocentric distances of 4.92, 4.58, 2.93 and 2.81 AU, and at 3.91 AU postperihelion. Each time, multi-filter photometry covering the range between 3.6-175 µm with eight to ten filters was performed to sample the spectral energy distribution of the comet. These measurements were used to determine dust temperatures for the cometary coma. The evolution of the strength of the silicate feature can be followed in the data as well as the flux deficit at longer wavelengths.

Interstellar Probe Measurements of Dust in Our Heliosphere

AGU Fall Meeting Abstracts, Dec 1, 2020

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

What Can an Interstellar Probe Mission at Large Heliocentric Distances Achieve with Remote Imaging and in Situ Dust Measurements

52nd Lunar and Planetary Science Conference 2021, Mar 1, 2021

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

RW Aur A: SpeX Spectral Evidence for Differentiated Planetesimal Formation, Migration, and Destruction in an ∼3 Myr Old Excited CTTS System

The Astrophysical Journal

We present 2007–2020 SpeX VISNIR spectral monitoring of the highly variable RW Aur A CTTS. We fin... more We present 2007–2020 SpeX VISNIR spectral monitoring of the highly variable RW Aur A CTTS. We find direct evidence for a highly excited, IR-bright, asymmetric, and time-variable system. Comparison of the spectral and temporal trends found determines five different components: (1) a stable continuum from 0.7 to 1.3 μm, with color temperature ∼4000 K, produced by the CTTS photospheric surface; (2) variable hydrogen emission lines emitted from hot excited hydrogen in the CTTS’s protostellar atmosphere/accretion envelope; (3) hot CO gas in the CTTS’s protostellar atmosphere/accretion envelope; (4) highly variable 1.8–5.0 μm thermal continuum emission with color temperature ranging from 1130 to 1650 K, due to a surrounding accretion disk that is spatially variable and has an inner wall at r ∼ 0.04 au and T ∼ 1650 K and outer edges at ∼1200 K; and (5) transient, bifurcated signatures of abundant Fe ii + associated S i, Si i, and Sr i in the system’s jet structures. The bifurcated signatur...

On the Origin and Thermal Stability of Arrokoths and Plutos Ices

We discuss in a thermodynamic, geologically empirical way the long-term nature of the stable majo... more We discuss in a thermodynamic, geologically empirical way the long-term nature of the stable majority ices that could be present in Kuiper Belt Object 2014 MU69 after its 4.6 Gyr residence in the EKB as a cold classical object. Considering the stability versus sublimation into vacuum for the suite of ices commonly found on comets, Centaurs, and KBOs at the average ~40K sunlit surface temperature of MU69 over Myr to Gyr, we find only 3 common ices that are truly refractory: HCN, CH3OH, and H2O (in order of increasing stability). NH3 and H2CO ices are marginally stable and may be removed by any positive temperature excursions in the EKB, as produced every 1e8 - 1e9 yrs by nearby supernovae and passing O/B stars. To date the NH team has reported the presence of abundant CH3OH and evidence for H2O on MU69s surface (Lisse et al. 2017, Grundy et al. 2020). NH3 has been searched for, but not found. We predict that future absorption feature detections will be due to an HCN or poly-H2CO base...

29P/Schwassmann-Wachmann: A Rosetta Stone for Amorphous Water Ice and CO <-> CO2 Conversion in Centaurs and Comets?

arXiv (Cornell University), Sep 19, 2022

Centaur 29P/Schwassmann-Wachmann 1 (SW1) is a highly active object orbiting in the transitional "... more Centaur 29P/Schwassmann-Wachmann 1 (SW1) is a highly active object orbiting in the transitional "Gateway" region between the Centaur and Jupiter Family Comet regions. SW1 is unique among the Centaurs in that it experiences quasi-regular major outbursts and produces CO emission continuously; however, the source of the CO is unclear. We argue that due to its very large size (~32 km radius), SW1 is likely still responding, via amorphous water ice (AWI) conversion to crystalline water ice (CWI), to the "sudden" change in its external thermal environment produced by its dynamical migration from the Kuiper belt to the Gateway Region at the inner edge of the Centaur region at 6 au. It is this conversion process that is the source of the abundant CO and dust released from the object during its quiescent and outburst phases. If correct, these arguments have a number of important predictions testable via remote sensing and in situ spacecraft characterization, including: the quick release on Myr timescales of CO from AWI conversion for any few km-scale scattered disk KBO transiting into the inner system; that to date SW1 has only converted between 50 to 65% of its nuclear AWI to CWI; that volume changes upon AWI conversion could have caused subsidence and cave-ins, but not significant mass wasting or crater loss; that SW1's coma should contain abundant amounts of CWI CO2-rich "dust" particles; and that when SW1 transits into the inner system within the next 10,000 years, it will be a very different kind of JFC comet.

Accepted for Publictation in the Astronomical Journal Infrared Spectroscopy of Comet 73P/Schwassmann-Wachmann 3 using the Spitzer Space Telescope

We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 µm therm... more We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 µm thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R∼100) data over the entire wavelength interval, along with images at 16 and 22 µm. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet-cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, ∼35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggests that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. The best-fit particle size distribution for SW3B has a form dn/da∼a −3.5 , close to that expected for dust in collisional equilibrium, while that for SW3C has dn/da∼a −4.0 , as seen mostly in active comets with strong directed jets such as C/1995 O1 Hale-Bopp. The total mass of dust in the comae plus nearby tail, extrapolated from to the field of view of the IRS peakup image arrays, is 3-5 x 10 8 kg for B and 7-9 x 10 8

Dust from collisions: A way to probe the composition of exo-planets?

In order to link infrared observations of dust formed during planet formation in debris disks to ... more In order to link infrared observations of dust formed during planet formation in debris disks to mid-infrared spectroscopic data of planetary materials from differentiated terrestrial and asteroidal bodies, we obtained absorption spectra of a representative suite of terrestrial crustal and mantle materials, and of typical Martian meteorites. A series of debris disk spectra characterized by a strong feature in the 9.0-9.5 µm range (HD23514, HD15407a, HD172555 and HD165014), is comparable to materials that underwent shock, collision or high temperature events. These are amorphous materials such as tektites, SiO2-glass, obsidian, and highly shocked shergottites as well as inclusions from mesosiderites (Group A). A second group (BD+20307,

Invited Article: Deep Impact instrument calibration

Review of Scientific Instruments, 2008

Calibration of NASA’s Deep Impact spacecraft instruments allows reliable scientific interpretatio... more Calibration of NASA’s Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [∼1.7pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of ∼9pixels. The charge coupled device (CCD) read noise is ∼1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is ...

Mid-infrared spectra of differentiated meteorites (achondrites): Comparison with astronomical observations of dust in protoplanetary and debris disks

Icarus, 2012

Mid-infrared (5 m to 25 m) transmission/absorption spectra of differentiated meteorites (achond... more Mid-infrared (5 m to 25 m) transmission/absorption spectra of differentiated meteorites (achondrites) were measured to permit comparison with astronomical observations of dust in different stages of evolution of young stellar objects. In contrast to primitive chondrites, achondrites underwent heavy metamorphism and/or extensive melting and represent more advanced stages of planetesimal evolution. Spectra were obtained from primitive achondrites (acapulcoite, winonaite, ureilite, and brachinite) and differentiated achondrites (eucrite, diogenite, aubrite, and mesosiderite silicates). The ureilite and brachinite show spectra dominated by olivine features, and the diogenite and aubrite by pyroxene features. The acapulcoite, winonaite, eucrite, and mesosiderite silicates exhibit more complex spectra, reflecting their multi-phase bulk mineralogy. Mixtures of spectra of the primitive achondrites and differentiated achondrites in various proportions show good similarities to the spectra of the few Myr old protoplanetary disks HD104237A and V410 Anon 13. A spectrum of the differentiated mesosiderite silicates is similar to the spectra of the mature debris disks HD172555 and HD165014. A mixture of spectra of the primitive ureilite and brachinite is similar to the spectrum of the debris disk HD113766. The results raise the possibility that materials produced in the early stage of planetesimal differentiation occur in the protoplanetary and debris disks.

Mid-infrared spectroscopy of components in chondrites: Search for processed materials in young Solar Systems and comets

Icarus, 2014

We obtained mid-infrared spectra of chondrules, matrix, CAIs and bulk material from primitive typ... more We obtained mid-infrared spectra of chondrules, matrix, CAIs and bulk material from primitive type 1-4 chondrites in order to compare them with the dust material in young, forming solar systems and around comets. Our aim is to investigate whether there are similarities between the first processed materials in our early Solar System and protoplanetary disks currently forming around other stars. Chondrule spectra can be divided into two groups. 1) Chondrules dominated by olivine features at ~11.3 µm and ~10.0 µm. 2) mesostasis rich chondrules that show main features at ~10 µm. Bulk ordinary chondrites show similar features to both groups. Fine-grained matrix is divided into three groups. 1) phyllosilicate-rich with a main band at ~10µm, 2) olivine-rich with bands at 11.3 µm and ~10 µm, 3) pyroxene-rich with several peaks between 9.3 µm and 11.2 µm. Impact shock processed matrix from Murchison (CM2) shows features from phyllosilicaterich, amorphous and olivine-rich material. CAIs show melilite/spinel-rich features between 10.2 µm and 12.5 µm. Astronomical spectra are divided into four groups based on their spectral characteristics-amorphous (group 1), pyroxene-rich (group 2), olivine-rich (group 3) and 'complex' (group 4). Group 2 is similar to enstatite-rich fine grained material like e.g. Kakangari (K3) matrix. Group 3 and 4 can be explained by a combination of varying concentrations of olivine and mesostasis-rich chondrules and fine-grained matrix, but also show very good agreement with shock processed material. Comparison of band ratios confirms the similarity with chondritic material e.g. for HD100546, while the inner disk of HD142527 show no sign of chondrule material. Comparison between the laboratory infrared-red IR data and astronomical spectra indicate a general similarity between primitive solar system materials and circumstellar dust and comets, especially in the inner disks of young solar systems. However, other amorphous materials like IDP/GEMS have to be taken into account.

Kuiper Belt object 2014MU69, Pluto and Phoebe as windows on the composition of the early solar nebula

Proceedings of the International Astronomical Union, 2019

The initial chemical composition of a proto-planetary nebula depends upon the degree to which 1) ... more The initial chemical composition of a proto-planetary nebula depends upon the degree to which 1) organic and ice components form on dust grains, 2) organic and molecular species form in the gas phase, 3) organics and ices are exchanged between the gas and solid state, and 4) the precursor and newly formed (more complex) materials survive and are modified in the developing planetary system. Infrared and radio observations of star-forming regions reveal that complex chemistry occurs on icy grains, often before stars even form. Additional processing, through the proto-planetary disk (PPD) further modifies most, but not all, of the initial materials. In fact, the modern Solar System still carries a fraction of its interstellar inheritance (Alexander et al.2017). Here we focus on three examples of small bodies in our Solar System, each containing chemical and dynamical clues to its origin and evolution: the small-cold classical Kuiper Belt object (KBO) 2014 MU69, Pluto, and Saturn’s moon...

Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis Ofwise/Neowiseobservations

The Astrophysical Journal, 2013

The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (S... more The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (SDOs) in the thermal infrared, including 15 new discoveries. We present analyses of these observations to estimate sizes and mean optical albedos. We find mean albedos of 0.08 ± 0.04 for the entire data set. Thermal fits yield average beaming parameters of 0.9 ± 0.2 that are similar for both SDO and Centaur sub-classes. Biased cumulative size distributions yield size-frequency distribution power law indices of ∼−1.7 ± 0.3. The data also reveal a relation between albedo and color at the 3σ level. No significant relation between diameter and albedos is found.

The temperature, thermal inertia, roughness and color of the nuclei of Comets 103P/Hartley 2 and 9P/Tempel 1

Icarus, 2013

The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on November 4th, 2010 (EPOXI mission) and... more The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on November 4th, 2010 (EPOXI mission) and Comet 9P/Tempel 1 on July 4th, 2005 (Deep Impact mission). During the two flybys, spatially resolved infrared (1.05-4.8 lm) spectra of the surface of the nucleus were acquired by the HRI-IR instrument. The analysis of these two data sets, obtained by the same instrument, offers a unique opportunity to understand, compare and contrast the surface thermal properties of these two comets. For this paper, we use spectral cubes with a spatial resolution of 30 m/pixel to 40 m/pixel for Hartley 2 and 160 m/pixel for Tempel 1. We focus our analysis on the color, temperature, thermal inertia and roughness of the nucleus. The two comets have the same color, moderately red, with an average slope of 3.0 ± 0.9% per kÅ to 3.5 ± 1.1% per kÅ. There are very small variations of the color across the surface, except for regions with water ice that are neutral to blue, and two dark spots with redder (4.5 ± 1.4% per kÅ) materials on Hartley 2. The nucleus thermal emission at all resolved spatial scales differs from that of a gray body with an infrared emissivity of 0.9-1.0, the discrepancy being more important for larger incidence angles. Moreover, the color temperature of Comets Hartley 2 and Tempel 1 is relatively homogeneous across the surface and does not vary strongly with incidence angle. These two effects mainly result from surface roughness and associated projected shadows. From the temperature rise on the morning terminator, we derive a thermal inertia lower than 250 W/K/m 2 /s 1/2 for Hartley 2 and lower than 45 W/K/m 2 /s 1/2 for Tempel 1 (3r upper limits). For Hartley 2 and Tempel 1, the temperature of the regions with exposed water ice is more than 100 K above the sublimation temperature of water ice ($200 K). This observation indicates that the thermal emission is dominated by dust, and that water ice is not intimately mixed with dust at the scale of observation, with water ice patches at the meter or sub-meter scale.

Astrophysics with New Horizons: Making the Most of a Generational Opportunity

Publications of the Astronomical Society of the Pacific, 2018

The outer solar system provides a unique, quiet vantage point from which to observe the universe ... more The outer solar system provides a unique, quiet vantage point from which to observe the universe around us, where measurements could enable several niche astrophysical science cases that are too difficult to perform near Earth. NASA's New Horizons mission comprises an instrument package that provides imaging capability from ultraviolet (UV) to near-infrared (near-IR) wavelengths with moderate spectral resolution located beyond the orbit of Pluto. A carefully designed survey with New Horizons can optimize the use of expendable propellant and the limited data telemetry bandwidth to allow several measurements, including a detailed understanding of the cosmic extragalactic background light; studies of the local and extragalactic UV background; measurements of the properties of dust and ice in the outer solar system; confirmation and characterization of transiting exoplanets; determinations of the mass of dark objects using gravitational microlensing; and rapid follow-up of transient events. New Horizons is currently in an extended mission designed to focus on Kuiper Belt science that will conclude in 2021. The astrophysics community has a unique, generational opportunity to use this mission for astronomical observation at heliocentric distances beyond 50 au in the next decade. In this paper, we discuss the potential science cases for such an extended mission, and provide an initial assessment of the most important operational requirements and observation strategies it would require. We conclude that New Horizons is capable of transformative science, and that it would make a valuable and unique asset for astrophysical science that is unlikely to be replicated in the near future.

Thermal alteration and differential sublimation can create Phaethon's “rock comet” activity and blue color

Icarus, 2022

In 2010 Jewitt and Li published a paper examining the behavior of "comet-asteroid transition obje... more In 2010 Jewitt and Li published a paper examining the behavior of "comet-asteroid transition object" 3200 Phaethon, arguing it was asteroid-like in its behavior throughout most of its orbit, but that near its perihelion, at a distance of only 0.165 AU from the sun, its dayside temperatures would be hot enough to vaporize rock (>1000 K, Hanus et al. 2016). Thus it would act like a "rock comet" as gases produced from evaporating rock were released from the body, in a manner similar to the more familiar sublimation of water ice into vacuum seen for comets coming within ~3 AU of the Sun. In this Note we predict that the same thermal effects that would create "rock comet" behavior with Qgas ~ 10 22 mol/sec at perihelion have also helped to greatly bluen Phaethon's surface via preferential thermal alteration and sublimative removal of Fe and refractory organics, known reddening and darkening agents. These predictions are testable by searching for signs of spectral bluening of the surfaces of other small bodies in Phaethon-like small perihelion orbits, including comets, and by in situ measurements of Phaethon's surface and coma composition near perihelion with the upcoming DESTINY+ mission (Kawakatsu & Itawa 2013, Arai et al. 2018) to Phaethon by JAXA.

Spitzer’s Solar System studies of comets, centaurs and Kuiper belt objects

Nature Astronomy, 2020

Widefield camera 3 for the Hubble Space Telescope

SPIE Proceedings, 2000

In June 1997, NASA made the decision to extend the end of the Hubble Space Telescope (HST) missio... more

A Predicted Dearth of Majority Hypervolatile Ices in Oort Cloud Comets

The Planetary Science Journal

We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the... more We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the 2019 January 1 MU69/Arrokoth flyby of Gladstone et al. and use them to make predictions about the rarity of majority hypervolatile (CO, N2, CH4) ices in Kuiper Belt objects and Oort Cloud comets. These predictions have a number of important implications for the study of the Oort Cloud, including the determination of hypervolatile-rich comets as the first objects emplaced into the Oort Cloud, the measurement of CO/N2/CH4 abundance ratios in the protoplanetary disk from hypervolatile-rich comets, and population statistical constraints on early (<20 Myr) planetary aggregation driven versus later (>50 Myr) planetary migration driven emplacement of objects into the Oort Cloud. They imply that the phenomenon of ultradistant active comets like C/2017K2 should be rare, and thus not a general characteristic of all comets. They also suggest that interstellar object 2I/Borisov may not have o...

Isophot Observations of Comet Hale-Bopp: Initial Data Reduction

arXiv: Astrophysics, Dec 9, 1998

Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board the Infrared Space ... more Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board the Infrared Space Observatory (ISO). Each time broadband photometry was performed using 4 different detectors, 5 apertures and, 10 filters covering the range between 3.6 to 175 µm. Calibration measurements using the internal Fine Calibration Source were done together with each individual measurement. Background observations were performed with identical instrument settings at the same positions on the sky several days after the comet observations. The observation strategy and the initial data reduction steps are described in some detail and the resulting in-band power values of the Hale-Bopp observations and their uncertainties are derived. Initial reduction of these measurements was performed in 3 steps: (1) processing of raw data by removing instrumental and energetic particle effects, (2) averaging of the individual signals, and (3) determination of the detector responsivities and their uncertainties. The detector signal is determined by two different methods and the best value is chosen. At the present level of processing uncertainties range from 10% to a factor of 3 for the low power levels at short wavelengths. The in-band power levels at different wavelengths varied over 3 orders of magnitude.

Isophot Observations Of Comet Hale-Bopp

Comet Hale-Bopp has been observed five times with ISOPHOT, the photometer on board the Infrared S... more Comet Hale-Bopp has been observed five times with ISOPHOT, the photometer on board the Infrared Space Observatory (ISO), four times before its perihelion passage at heliocentric distances of 4.92, 4.58, 2.93 and 2.81 AU, and at 3.91 AU postperihelion. Each time, multi-filter photometry covering the range between 3.6-175 µm with eight to ten filters was performed to sample the spectral energy distribution of the comet. These measurements were used to determine dust temperatures for the cometary coma. The evolution of the strength of the silicate feature can be followed in the data as well as the flux deficit at longer wavelengths.

Interstellar Probe Measurements of Dust in Our Heliosphere

AGU Fall Meeting Abstracts, Dec 1, 2020

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

What Can an Interstellar Probe Mission at Large Heliocentric Distances Achieve with Remote Imaging and in Situ Dust Measurements

52nd Lunar and Planetary Science Conference 2021, Mar 1, 2021

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

RW Aur A: SpeX Spectral Evidence for Differentiated Planetesimal Formation, Migration, and Destruction in an ∼3 Myr Old Excited CTTS System

The Astrophysical Journal

We present 2007–2020 SpeX VISNIR spectral monitoring of the highly variable RW Aur A CTTS. We fin... more We present 2007–2020 SpeX VISNIR spectral monitoring of the highly variable RW Aur A CTTS. We find direct evidence for a highly excited, IR-bright, asymmetric, and time-variable system. Comparison of the spectral and temporal trends found determines five different components: (1) a stable continuum from 0.7 to 1.3 μm, with color temperature ∼4000 K, produced by the CTTS photospheric surface; (2) variable hydrogen emission lines emitted from hot excited hydrogen in the CTTS’s protostellar atmosphere/accretion envelope; (3) hot CO gas in the CTTS’s protostellar atmosphere/accretion envelope; (4) highly variable 1.8–5.0 μm thermal continuum emission with color temperature ranging from 1130 to 1650 K, due to a surrounding accretion disk that is spatially variable and has an inner wall at r ∼ 0.04 au and T ∼ 1650 K and outer edges at ∼1200 K; and (5) transient, bifurcated signatures of abundant Fe ii + associated S i, Si i, and Sr i in the system’s jet structures. The bifurcated signatur...

On the Origin and Thermal Stability of Arrokoths and Plutos Ices

We discuss in a thermodynamic, geologically empirical way the long-term nature of the stable majo... more We discuss in a thermodynamic, geologically empirical way the long-term nature of the stable majority ices that could be present in Kuiper Belt Object 2014 MU69 after its 4.6 Gyr residence in the EKB as a cold classical object. Considering the stability versus sublimation into vacuum for the suite of ices commonly found on comets, Centaurs, and KBOs at the average ~40K sunlit surface temperature of MU69 over Myr to Gyr, we find only 3 common ices that are truly refractory: HCN, CH3OH, and H2O (in order of increasing stability). NH3 and H2CO ices are marginally stable and may be removed by any positive temperature excursions in the EKB, as produced every 1e8 - 1e9 yrs by nearby supernovae and passing O/B stars. To date the NH team has reported the presence of abundant CH3OH and evidence for H2O on MU69s surface (Lisse et al. 2017, Grundy et al. 2020). NH3 has been searched for, but not found. We predict that future absorption feature detections will be due to an HCN or poly-H2CO base...