Geological and geophysical constraints on Itokawa’s past spin periods

Hannah C.M. Susorney; Lydia C. Philpott; Ronald L. Ballouz; Catherine L. Johnson; Benjamin Rozitis; Erica R. Jawin

doi:10.1016/j.icarus.2020.114265

Geological and geophysical constraints on Itokawa’s past spin periods

Hannah C.M. Susorney^*
, Lydia C. Philpott
, Ronald L. Ballouz
, Catherine L. Johnson
, Benjamin Rozitis
, Erica R. Jawin

^*Corresponding author for this work

School of Earth Sciences

Research output: Contribution to journal › Article (Academic Journal) › peer-review

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Abstract

Itokawa has two distinct terrain types, rough highlands, and smooth lowlands. The lowlands formed by the movement of fine-grained materials from the highlands into topographic lows, covering up large boulders and producing a smooth surface. The topography of asteroids is a function of the shape, interior density, and spin rate. Itokawa, like many near-earth objects, may have experienced changes in its spin period due to YORP. Changes in spin period compared with the current 12.13 h period, may result in changes in the location of topographic lows and thus the concentration of fines in the lows. Under faster spin periods, 8 h or less, the northern topographic low, currently Sagamihara, changes location, but the southern lowland, Muses-Sea, stays in the same location. Above 8 h the topographic lows match the current geographic extent of the fine-grain lowlands. Current estimates of the timescale of regolith migration based on seismic shaking span several orders of magnitude. However, if these can be further refined, the location of the northern lowlands could be used as a constraint on the past spin rates of Itokawa The methods used in this study could be applied to other asteroids and may place an independent constraint on past spin periods.

Original language	English
Article number	114265
Number of pages	7
Journal	Icarus
Volume	357
Early online date	11 Dec 2020
DOIs	https://doi.org/10.1016/j.icarus.2020.114265
Publication status	Published - 15 Mar 2021

Bibliographical note

Funding Information:
We thank the two reviewers who provided helpful reviews on this manuscript. This research was supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada (HCMS, LCP, CLJ) and by the UK Science Technology Facilities Council (BR). HCMS was additionally supported by the European Unions H2020 Marie Sklodowska-Curie Individual Research Fellowship . We thank the developers of the Small Body Mapping Tool and the OSIRIS-REX Altimetry Toolkit which were used in this study. Both software packages are available at sbmt.jhuapl.edu .

Publisher Copyright:
© 2020 Elsevier Inc.

Keywords

Asteroids
Topography
25143 Itokawa
YORP

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10.1016/j.icarus.2020.114265

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title = "Geological and geophysical constraints on Itokawa{\textquoteright}s past spin periods",

abstract = "Itokawa has two distinct terrain types, rough highlands, and smooth lowlands. The lowlands formed by the movement of fine-grained materials from the highlands into topographic lows, covering up large boulders and producing a smooth surface. The topography of asteroids is a function of the shape, interior density, and spin rate. Itokawa, like many near-earth objects, may have experienced changes in its spin period due to YORP. Changes in spin period compared with the current 12.13 h period, may result in changes in the location of topographic lows and thus the concentration of fines in the lows. Under faster spin periods, 8 h or less, the northern topographic low, currently Sagamihara, changes location, but the southern lowland, Muses-Sea, stays in the same location. Above 8 h the topographic lows match the current geographic extent of the fine-grain lowlands. Current estimates of the timescale of regolith migration based on seismic shaking span several orders of magnitude. However, if these can be further refined, the location of the northern lowlands could be used as a constraint on the past spin rates of Itokawa The methods used in this study could be applied to other asteroids and may place an independent constraint on past spin periods.",

keywords = "Asteroids, Topography, 25143 Itokawa, YORP",

author = "Susorney, \{Hannah C.M.\} and Philpott, \{Lydia C.\} and Ballouz, \{Ronald L.\} and Johnson, \{Catherine L.\} and Benjamin Rozitis and Jawin, \{Erica R.\}",

note = "Funding Information: We thank the two reviewers who provided helpful reviews on this manuscript. This research was supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada (HCMS, LCP, CLJ) and by the UK Science Technology Facilities Council (BR). HCMS was additionally supported by the European Unions H2020 Marie Sklodowska-Curie Individual Research Fellowship . We thank the developers of the Small Body Mapping Tool and the OSIRIS-REX Altimetry Toolkit which were used in this study. Both software packages are available at sbmt.jhuapl.edu . Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",

year = "2021",

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doi = "10.1016/j.icarus.2020.114265",

language = "English",

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AU - Susorney, Hannah C.M.

AU - Philpott, Lydia C.

AU - Ballouz, Ronald L.

AU - Johnson, Catherine L.

AU - Rozitis, Benjamin

AU - Jawin, Erica R.

N1 - Funding Information: We thank the two reviewers who provided helpful reviews on this manuscript. This research was supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada (HCMS, LCP, CLJ) and by the UK Science Technology Facilities Council (BR). HCMS was additionally supported by the European Unions H2020 Marie Sklodowska-Curie Individual Research Fellowship . We thank the developers of the Small Body Mapping Tool and the OSIRIS-REX Altimetry Toolkit which were used in this study. Both software packages are available at sbmt.jhuapl.edu . Publisher Copyright: © 2020 Elsevier Inc.

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N2 - Itokawa has two distinct terrain types, rough highlands, and smooth lowlands. The lowlands formed by the movement of fine-grained materials from the highlands into topographic lows, covering up large boulders and producing a smooth surface. The topography of asteroids is a function of the shape, interior density, and spin rate. Itokawa, like many near-earth objects, may have experienced changes in its spin period due to YORP. Changes in spin period compared with the current 12.13 h period, may result in changes in the location of topographic lows and thus the concentration of fines in the lows. Under faster spin periods, 8 h or less, the northern topographic low, currently Sagamihara, changes location, but the southern lowland, Muses-Sea, stays in the same location. Above 8 h the topographic lows match the current geographic extent of the fine-grain lowlands. Current estimates of the timescale of regolith migration based on seismic shaking span several orders of magnitude. However, if these can be further refined, the location of the northern lowlands could be used as a constraint on the past spin rates of Itokawa The methods used in this study could be applied to other asteroids and may place an independent constraint on past spin periods.

AB - Itokawa has two distinct terrain types, rough highlands, and smooth lowlands. The lowlands formed by the movement of fine-grained materials from the highlands into topographic lows, covering up large boulders and producing a smooth surface. The topography of asteroids is a function of the shape, interior density, and spin rate. Itokawa, like many near-earth objects, may have experienced changes in its spin period due to YORP. Changes in spin period compared with the current 12.13 h period, may result in changes in the location of topographic lows and thus the concentration of fines in the lows. Under faster spin periods, 8 h or less, the northern topographic low, currently Sagamihara, changes location, but the southern lowland, Muses-Sea, stays in the same location. Above 8 h the topographic lows match the current geographic extent of the fine-grain lowlands. Current estimates of the timescale of regolith migration based on seismic shaking span several orders of magnitude. However, if these can be further refined, the location of the northern lowlands could be used as a constraint on the past spin rates of Itokawa The methods used in this study could be applied to other asteroids and may place an independent constraint on past spin periods.

KW - Asteroids

KW - Topography

KW - 25143 Itokawa

KW - YORP

U2 - 10.1016/j.icarus.2020.114265

DO - 10.1016/j.icarus.2020.114265

M3 - Article (Academic Journal)

SN - 0019-1035

VL - 357

JO - Icarus

JF - Icarus

M1 - 114265

ER -

Geological and geophysical constraints on Itokawa’s past spin periods

Abstract

Bibliographical note

Keywords

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