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15 results on '"Howett, C. J. A."'

1. Surface compositions across Pluto and Charon

Author

Grundy, W. M., Binzel, R. P., Buratti, B. J., Cook, J. C., Cruikshank, D. P., Ore, C. M. Dalle, Earle, A. M., Ennico, K., Howett, C. J. A., Lunsford, A. W., Olkin, C. B., Parker, A. H., Philippe, S., Protopapa, S., Quirico, E., Reuter, D. C., Schmitt, B., Singer, K. N., Verbiscer, A. J., Beyer, R. A., Buie, M. W., Cheng, A. F., Jennings, D. E., Linscott, I. R., Parker, J. Wm., Schenk, P. M., Spencer, J. R., Stansberry, J. A., Stern, S. A., Throop, H. B., Tsang, C. C. C., Weaver, H. A., Weigle, G. E., and Young, L. A.

Published
2016

2. The small satellites of Pluto as observed by New Horizons

Author

Weaver, H. A., Buie, M. W., Buratti, B. J., Grundy, W. M., Lauer, T. R., Olkin, C. B., Parker, A. H., Porter, S. B., Showalter, M. R., Spencer, J. R., Stern, S. A., Verbiscer, A. J., McKinnon, W. B., Moore, J. M., Robbins, S. J., Schenk, P., Singer, K. N., Barnouin, O. S., Cheng, A. F., Ernst, C. M., Lisse, C. M., Jennings, D. E., Lunsford, A. W., Reuter, D. C., Hamilton, D. P., Kaufmann, D. E., Ennico, K., Young, L. A., Beyer, R. A., Binzel, R. P., Bray, V. J., Chaikin, A. L., Cook, J. C., Cruikshank, D. P., Ore, C. M. Dalle, Earle, A. M., Gladstone, G. R., Howett, C. J. A., Linscott, I. R., Nimmo, F., Parker, J. Wm., Philippe, S., Protopapa, S., Reitsema, H. J., Schmitt, B., Stryk, T., Summers, M. E., Tsang, C. C. C., Throop, H. H. B., White, O. L., and Zangari, A. M.

Published
2016

3. The Pluto system: Initial results from its exploration by New Horizons

Author

Stern, S. A., Bagenal, F., Ennico, K., Gladstone, G. R., Grundy, W. M., McKinnon, W. B., Moore, J. M., Olkin, C. B., Spencer, J. R., Weaver, H. A., Young, L. A., Andert, T., Andrews, J., Banks, M., Bauer, B., Bauman, J., Barnouin, O. S., Bedini, P., Beisser, K., Beyer, R. A., Bhaskaran, S., Binzel, R. P., Birath, E., Bird, M., Bogan, D. J., Bowman, A., Bray, V. J., Brozovic, M., Bryan, C., Buckley, M. R., Buie, M. W., Buratti, B. J., Bushman, S. S., Calloway, A., Carcich, B., Cheng, A. F., Conard, S., Conrad, C. A., Cook, J. C., Cruikshank, D. P., Custodio, O. S., Ore, C. M. Dalle, Deboy, C., Dischner, Z. J. B., Dumont, P., Earle, A. M., Elliott, H. A., Ercol, J., Ernst, C. M., Finley, T., Flanigan, S. H., Fountain, G., Freeze, M. J., Greathouse, T., Green, J. L., Guo, Y., Hahn, M., Hamilton, D. P., Hamilton, S. A., Hanley, J., Harch, A., Hart, H. M., Hersman, C. B., Hill, A., Hill, M. E., Hinson, D. P., Holdridge, M. E., Horanyi, M., Howard, A. D., Howett, C. J. A., Jackman, C., Jacobson, R. A., Jennings, D. E., Kammer, J. A., Kang, H. K., Kaufmann, D. E., Kollmann, P., Krimigis, S. M., Kusnierkiewicz, D., Lauer, T. R., Lee, J. E., Lindstrom, K. L., Linscott, I. R., Lisse, C. M., Lunsford, A. W., Mallder, V. A., Martin, N., McComas, D. J., McNutt, R. L., Mehoke, D., Mehoke, T., Melin, E. D., Mutchler, M., Nelson, D., Nimmo, F., Nunez, J. I., Ocampo, A., Owen, W. M., Paetzold, M., Page, B., Parker, A. H., Parker, J. W., Pelletier, F., Peterson, J., Pinkine, N., Piquette, M., Porter, S. B., Protopapa, S., Redfern, J., Reitsema, H. J., Reuter, D. C., Roberts, J. H., Robbins, S. J., Rogers, G., Rose, D., Runyon, K., Retherford, K. D., Ryschkewitsch, M. G., Schenk, P., Schindhelm, E., Sepan, B., Showalter, M. R., Singer, K. N., Soluri, M., Stanbridge, D., Steffl, A. J., Strobel, D. F., Stryk, T., Summers, M. E., Szalay, J. R., Tapley, M., Taylor, A., Taylor, H., Throop, H. B., Tsang, C. C. C., Tyler, G. L., Umurhan, O. M., Verbiscer, A. J., Versteeg, M. H., Vincent, M., Webbert, R., Weidner, S., Weigle, G. E., White, O. L., Whittenburg, K., Williams, B. G., Williams, K., Williams, S., Woods, W. W., Zangari, A. M., and Zirnstein, E.

Published
2015

4. PLANETARY SCIENCE: The Pluto system: Initial results from its exploration by New Horizons

Author

Stern, S. A., Bagenal, F., Ennico, K., Gladstone, G. R., Grundy, W. M., McKinnon, W. B., Moore, J. M., Olkin, C. B., Spencer, J. R., Weaver, H. A., Young, L. A., Andert, T., Andrews, J., Banks, M., Bauer, B., Bauman, J., Barnouin, O. S., Bedini, P., Beisser, K., Beyer, R. A., Bhaskaran, S., Binzel, R. P., Birath, E., Bird, M., Bogan, D. J., Bowman, A., Bray, V. J., Brozovic, M., Bryan, C., Buckley, M. R., Buie, M. W., Buratti, B. J., Bushman, S. S., Calloway, A., Carcich, B., Cheng, A. F., Conard, S., Conrad, C. A., Cook, J. C., Cruikshank, D. P., Custodio, O. S., Ore, Dalle C. M., Deboy, C., Dischner, Z. J. B., Dumont, P., Earle, A M., Elliott, H. A, Ercol, J., Ernst, C. M., Finley, T., Flanigan, S. H., Fountain, G., Freeze, M. J., Greathouse, T., Green, J. L., Guo, Y., Hahn, M., Hamilton, D. P., Hamilton, S. A., Hanley, J., Harch, A., Hart, H. M., Hersman, C. B., Hill, A., Hill, M. E., Hinson, D. P., Holdridge, M. E., Horanyi, M., Howard, A. D., Howett, C. J. A., Jackman, C., Jacobson, R. A., Jennings, D. E., Kammer, J. A., Kang, H. K., Kaufmann, D. E., Kollmann, P., Krimigis, S. M., Kusnierkiewicz, D., Lauer, T. R., Lee, J. E., Lindstrom, K. L., Linscott, I. R., Lisse, C. M., Lunsford, A. W., Mallder, V. A., Martin, N., McComas, D. J., McNutt, R. L., Jr., Mehoke, D., Mehoke, T., Melin, E. D., Mutchler, M., Nelson, D., Nimmo, F., Nunez, J. I., Ocampo, A., Owen, W. M., Paetzold, M., Page, B., Parker, A. H., Parker, J. W., Pelletier, F., Peterson, J., Pinkine, N., Piquette, M., Porter, S. B., Protopapa, S., Redfern, J., Reitsema, H. J., Reuter, D. C., Roberts, J. H., Bobbins, S. J., Rogers, G., Rose, D., Runyon, K., Retherford, K. D., Ryschkewitsch, M. G., Schenk, P., Schindhelm, E., Sepan, B., Showalter, M. R., Singer, K. N., Soluri, M., Stanbridge, D., Steffl, A. J., Strobel, D. F., Stryk, T., Summers, M. E., Szalay, J. R., Tapley, M., Taylor, A., Taylor, H., Throop, H. B., Tsang, C. C. C., Tyler, G. L., Umurhan, O. M., Verbiscer, A. J., Versteeg, M. H., Vincent, M., Webbert, R., Weidner, S., Weigle, G. E., II, White, O. L., Whittenburg, K., Williams, B. G., Williams, K., Williams, S., Woods, W. W., Zangari, A. M., and Zirnstein, E.

Published
2015
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5. The formation of Charons red poles from seasonally cold-trapped volatiles

Author

Grundy, W. M., Cruikshank, D. P., Gladstone, G. R., Howett, C. J. A., Lauer, T. R., Spencer, J. R., Summers, M. E., Buie, M. W., Earle, A. M., Ennico, K., Parker, J. Wm., Porter, S. B., Singer, K. N., Stern, S. A., Verbiscer, A. J., Beyer, R. A., Binzel, R. P., Buratti, B. J., Cook, J. C., Dalle Ore, C. M., Olkin, C. B., Parker, A. H., Protopapa, S., Quirico, E., Retherford, K. D., Robbins, S. J., Schmitt, B., Stansberry, J. A., Umurhan, O. M., Weaver, H. A., Young, L. A., Zangari, A. M., Bray, V. J., Cheng, A. F., McKinnon, W. B., McNutt, R. L., Moore, J. M., Nimmo, F., Reuter, D. C., Schenk, P. M., Bagenal, F., Andert, T., Barnouin, O., Bird, M., Brozovi, M., Elliott, H. A., Greathouse, T. K., Hahn, M., Hamilton, D. P., Hill, M. E., Hinson, D. P., Hofgartner, J., Hornyi, M., Howard, A. D., Jennings, D. E., Kammer, J. A., Kollmann, P., Lavvas, P., Linscott, I. R., Lisse, C. M., Lunsford, A. W., McComas, D. J., McNutt Jr., R. L., Mutchler, M., Nunez, J. I., Paetzold, M., Wm. Parker, J., Philippe, S., Piquette, M., Reitsema, H. J., Roberts, J. H., Runyon, K., Schindhelm, E., Showalter, M. R., Steffl, A. J., Strobel, D. F., Stryk, T., Szalay, J. R., Throop, H. B., Tsang, C. C. C., Tyler, G. L., Versteeg, M. H., Weigle II, G. E., White, O. L., Woods, W. W., and Young, E. F.

Subjects
Charon (Satellite) -- Natural history -- Observations, Pluto (Dwarf planet) -- Natural history -- Observations, Planetary atmospheres -- Natural history -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): W. M. Grundy (corresponding author) [1]; D. P. Cruikshank [2]; G. R. Gladstone [3]; C. J. A. Howett [4]; T. R. Lauer [5]; J. R. Spencer [4]; M. E. [...]

Published
2016
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8. PHOTOMETRIC PROPERTIES OF PLUTO'S MAIN SURFACE UNITS.

Author

Protopapa, S., Olkin, C., Grundy, W., Li, J. Y., Verbiscer, A., Cruikshank, D. P., Howett, C. J. A., Stem, A., Weaver, H. A., and Young, L. A.

Subjects
PLUTO (Dwarf planet), PROPERTY, HORIZON
Published
2019

9. THE COLORS AND PHOTOMETRIC PROPERTIES OF PLUTO.

Author

Olkin, C. B., Howett, C. J. A., Protopapa, S., Grundy, W. M., Buie, M. W., Verbiscer, A., Stern, S. A., Weaver, H. A., Young, L. A., and Ennico, K.

Subjects
PLUTO (Dwarf planet), COLORS, LIGHT filters
Published
2019

10. CHARON'S COLORS AND PHOTOMETRIC PROPERTIES.

Author

Howett, C. J. A., Olkin, C. B., Protopapa, S., Grundy, W. M., Verbiscer, A., and Buratti, B. J.

Subjects
PLUTO (Dwarf planet), COLORS, LIGHT filters
Published
2019

11. PHOTOMETRY AND ALBEDO MAPS OF PLUTO AND CHARON.

Author

Buratti, B. J., Hofgartner, J., Hillier, J. H., Hicks, M. D., Verbiscer, A. J., Stern, S. A., Weaver, H. A., Howett, C. J. A., Young, L. A., Cheng, A., Ennico, K., and Olkin, C. B.

Subjects
PLUTO (Dwarf planet), ALBEDO, PHOTOMETRY, SOLAR system, SPACE sciences, KUIPER belt
Published
2019

12. Bolometric Bond Albedo and Thermal Inertia Maps of Mimas.

Author

Howett CJA, Spencer JR, and Nordheim T

Abstract

In 2011 a thermally anomalous region was discovered on Mimas, Saturn's innermost major icy satellite (Howett et al., 2011). The anomalous region is a lens-like shape located at low latitudes on Mimas' leading hemisphere. It manifests as a region with warmer nighttime temperatures, and cooler daytime ones than its surroundings. The thermally anomalous region is spatially correlated with a darkening in Mimas' IR/UV surface color (Schenk et al. 2011) and the region preferentially bombarded by high-energy electrons (Paranicas et al., 2012, 2014; Nordheim et al., 2017). We use data from Cassini's Composite Infrared Spectrometer (CIRS) to map Mimas' surface temperatures and its thermophysical properties. This provides a dramatic improvement on the work in Howett et al. (2011), where the values were determined at only two regions on Mimas (one inside, and another outside of the anomalous region). We use all spatially-resolved scans made by CIRS' focal plane 3 (FP3, 600 to 1100 cm -1 ) of Mimas' surface, which are largely daytime observations but do include one nighttime one. The resulting temperature maps confirm the presence and location of Mimas' previously discovered thermally anomalous region. No other thermally anomalous regions were discovered, although we note that the surface coverage is incomplete on Mimas' leading and anti-Saturn hemisphere. The thermal inertia map confirms that the anomalous region has a notably higher thermal inertia than its surroundings: 98±42 J m -2 K -1 s -1/2 inside of the anomaly, compared to 34±32 J m -2 K -1 s -1/2 outside. The albedo inside and outside of the anomalous region agrees within their uncertainty: 0.45±0.08 inside compared to 0.41±0.07 outside the anomaly. Interestingly the albedo appears brighter inside the anomaly region, which may not be surprising given this region does appear brighter at some UV wavelengths (0.338 μm, see Schenk et al., 2011). However, this result should be treated with caution because, as previously stated, statistically the albedo of these two regions is the same when their uncertainties are considered. These thermal inertia and albedo values determined here are consistent with those found by Howett et al. (2011), who determined the thermal inertia inside the anomaly to be 66±23 J m -2 K -1 s -1/2 and <16 J m -2 K -1 s -1/2 outside, with albedos that varied from 0.49 to 0.70.

Published
2020
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13. The geology and geophysics of Kuiper Belt object (486958) Arrokoth.

Author

Spencer JR, Stern SA, Moore JM, Weaver HA, Singer KN, Olkin CB, Verbiscer AJ, McKinnon WB, Parker JW, Beyer RA, Keane JT, Lauer TR, Porter SB, White OL, Buratti BJ, El-Maarry MR, Lisse CM, Parker AH, Throop HB, Robbins SJ, Umurhan OM, Binzel RP, Britt DT, Buie MW, Cheng AF, Cruikshank DP, Elliott HA, Gladstone GR, Grundy WM, Hill ME, Horanyi M, Jennings DE, Kavelaars JJ, Linscott IR, McComas DJ, McNutt RL Jr, Protopapa S, Reuter DC, Schenk PM, Showalter MR, Young LA, Zangari AM, Abedin AY, Beddingfield CB, Benecchi SD, Bernardoni E, Bierson CJ, Borncamp D, Bray VJ, Chaikin AL, Dhingra RD, Fuentes C, Fuse T, Gay PL, Gwyn SDJ, Hamilton DP, Hofgartner JD, Holman MJ, Howard AD, Howett CJA, Karoji H, Kaufmann DE, Kinczyk M, May BH, Mountain M, Pätzold M, Petit JM, Piquette MR, Reid IN, Reitsema HJ, Runyon KD, Sheppard SS, Stansberry JA, Stryk T, Tanga P, Tholen DJ, Trilling DE, and Wasserman LH

Abstract

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, is composed of primitive objects preserving information about Solar System formation. In January 2019, the New Horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) Arrokoth (provisional designation 2014 MU 69 ). Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters in diameter) within a radius of 8000 kilometers. Arrokoth has a lightly cratered, smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Published
2020
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14. Initial results from the New Horizons exploration of 2014 MU 69 , a small Kuiper Belt object.

Author

Stern SA, Weaver HA, Spencer JR, Olkin CB, Gladstone GR, Grundy WM, Moore JM, Cruikshank DP, Elliott HA, McKinnon WB, Parker JW, Verbiscer AJ, Young LA, Aguilar DA, Albers JM, Andert T, Andrews JP, Bagenal F, Banks ME, Bauer BA, Bauman JA, Bechtold KE, Beddingfield CB, Behrooz N, Beisser KB, Benecchi SD, Bernardoni E, Beyer RA, Bhaskaran S, Bierson CJ, Binzel RP, Birath EM, Bird MK, Boone DR, Bowman AF, Bray VJ, Britt DT, Brown LE, Buckley MR, Buie MW, Buratti BJ, Burke LM, Bushman SS, Carcich B, Chaikin AL, Chavez CL, Cheng AF, Colwell EJ, Conard SJ, Conner MP, Conrad CA, Cook JC, Cooper SB, Custodio OS, Dalle Ore CM, Deboy CC, Dharmavaram P, Dhingra RD, Dunn GF, Earle AM, Egan AF, Eisig J, El-Maarry MR, Engelbrecht C, Enke BL, Ercol CJ, Fattig ED, Ferrell CL, Finley TJ, Firer J, Fischetti J, Folkner WM, Fosbury MN, Fountain GH, Freeze JM, Gabasova L, Glaze LS, Green JL, Griffith GA, Guo Y, Hahn M, Hals DW, Hamilton DP, Hamilton SA, Hanley JJ, Harch A, Harmon KA, Hart HM, Hayes J, Hersman CB, Hill ME, Hill TA, Hofgartner JD, Holdridge ME, Horányi M, Hosadurga A, Howard AD, Howett CJA, Jaskulek SE, Jennings DE, Jensen JR, Jones MR, Kang HK, Katz DJ, Kaufmann DE, Kavelaars JJ, Keane JT, Keleher GP, Kinczyk M, Kochte MC, Kollmann P, Krimigis SM, Kruizinga GL, Kusnierkiewicz DY, Lahr MS, Lauer TR, Lawrence GB, Lee JE, Lessac-Chenen EJ, Linscott IR, Lisse CM, Lunsford AW, Mages DM, Mallder VA, Martin NP, May BH, McComas DJ, McNutt RL Jr, Mehoke DS, Mehoke TS, Nelson DS, Nguyen HD, Núñez JI, Ocampo AC, Owen WM, Oxton GK, Parker AH, Pätzold M, Pelgrift JY, Pelletier FJ, Pineau JP, Piquette MR, Porter SB, Protopapa S, Quirico E, Redfern JA, Regiec AL, Reitsema HJ, Reuter DC, Richardson DC, Riedel JE, Ritterbush MA, Robbins SJ, Rodgers DJ, Rogers GD, Rose DM, Rosendall PE, Runyon KD, Ryschkewitsch MG, Saina MM, Salinas MJ, Schenk PM, Scherrer JR, Schlei WR, Schmitt B, Schultz DJ, Schurr DC, Scipioni F, Sepan RL, Shelton RG, Showalter MR, Simon M, Singer KN, Stahlheber EW, Stanbridge DR, Stansberry JA, Steffl AJ, Strobel DF, Stothoff MM, Stryk T, Stuart JR, Summers ME, Tapley MB, Taylor A, Taylor HW, Tedford RM, Throop HB, Turner LS, Umurhan OM, Van Eck J, Velez D, Versteeg MH, Vincent MA, Webbert RW, Weidner SE, Weigle GE 2nd, Wendel JR, White OL, Whittenburg KE, Williams BG, Williams KE, Williams SP, Winters HL, Zangari AM, and Zurbuchen TH

Abstract

The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU 69 , a cold classical Kuiper Belt object approximately 30 kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU 69 is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU 69 's origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Published
2019
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15. Maps of Tethys' Thermophysical Properties.

Author

Howett CJA, Spencer JR, Hurford T, Verbiscer A, and Segura M

Abstract

On 11 th April 2015 Cassini's Composite Infrared Spectrometer (CIRS) made a series of observations of Tethys' daytime anti-Saturn hemisphere over a nine-hour time period. During this time the sub-spacecraft position was remarkably stable (0.3° S to 3.9° S; 153.2° W to 221.8° W), and so these observations provide unprecedented coverage of diurnal temperature variations on Tethys' anti-Saturn hemisphere. In 2012 a thermal anomaly was discovered at low latitudes on Tethys' leading hemisphere; it appears cooler during the day and warmer at night than its surroundings (Howett et al., 2012) and is spatially correlated with a decrease in the IR3/UV3 visible color ratio (Schenk et al., 2011). The cause of this anomaly is believed to be surface alteration by high-energy electrons, which preferentially bombard low-latitudes of Tethys' leading hemisphere (Schenk et al., 2011; Howett et al., 2012; Paranicas et al. 2014; Schaible et al., 2017). The thermal anomaly was quickly dubbed "Pac-Man" due to its resemblance to the 1980s video game icon. We use these daytime 2015 CIRS data, along with two sets of nighttime CIRS observations of Tethys (from 27 June 2007 and 17 August 2015) to make maps of bolometric Bond albedo and thermal inertia variations across the anti-Saturn hemisphere of Tethys (including the edge of its Pac-Man region). These maps confirm the presence of the Pac-Man thermal anomaly and show that while Tethys' bolometric Bond albedo varies negligibly outside and inside the anomaly (0.69±0.02 inside, compared to 0.71±0.04 outside) the thermal inertia varies dramatically (29±10 J m -2 K -1 s -1/2 inside, compared to 9±4 J m -2 K -1 s -1/2 outside). These thermal inertias are in keeping with previously published values: 25±3 J m -2 K -1 s -1/2 inside, and 5±1 J m -2 K -1 s -1/2 outside the anomaly (Howett et al., 2012). A detailed analysis shows that on smaller spatial-scales the bolometric Bond albedo does vary: increasing to a peak value at 180° W. For longitudes between ~100° W and ~160° W the thermal inertia increases from northern to southern latitudes, while the reverse is true for bolometric Bond albedo. The thermal inertia on Tethys generally increases towards the center of its leading hemisphere but also displays other notable small-scale variations. These thermal inertia and bolometric Bond albedo variations are perhaps due to differences in competing surface modification by E ring grains and high-energy electrons which both bombard Tethys' leading hemisphere (but in different ways). A comparison between the observed temperatures and our best thermal model fits shows notable discrepancies in the morning warming curve, which may provide evidence of regional variations in surface roughness effects, perhaps again due to variations in surface alteration mechanisms.

Published
2019
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