The discovery and orbit of 1993 (243)1 Dactyl

Michael J S Belton, Beatrice E A Mueller, Louis A. D'Amario, Dennis V. Byrnes, Kenneth P. Klaasen, Steven Synnott, Herbert Breneman, Torrence V. Johnson, Peter C. Thomas, Joseph Veverka, Ann P. Harch, Merton E. Davies, William J. Merline, Clark R. Chapman, Donald Davis, Tilmann Denk, Gerhard Neukum, Jean Marc Petit, Richard J. Greenberg, Alex Storrs & 1 others Benjamin Zellner

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida-Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate features being consistent with radiation hits. We deduce a manifold of osculating two-body orbits that approximate Dactyl's motion over the observed orbital arc depending on the assumed mass of Ida. At the time of Galileo's encounter, Dactyl was found to be 85 km from the center of Ida, moving at ∼6 m · sec-1 in the same direction as Ida's retrograde spin. The inclination of its orbit is ∼172° in Ida's equatorial system (IAU definition). It was not possible to obtain a definitive orbit or measure of Ida's mass from the observed motion even though supplemental techniques (search for Dactyl's shadow on Ida, changes in angular diameter and brightness, and attempts to determine the spin of Dactyl) were explored. The influence of Ida's irregular gravitational field and solar perturbations on two-body motion are evaluated and found to be undetectable in the observed orbital arc. These effects may, however, strongly influence the motion over orbital time scales. Limits to the value of Ida's gravitation parameter, GM, are derived. A robust lower limit, GM > 0.0023 km3 · sec-2, is obtained by requiring Dactyl's orbit to be bound. Hubble Space Telescope observations, which show no evidence of Dactyl on a hyperbolic orbit, excludes values of GM in the range 0.00216 < GM < 0.0023 km3 · sec-2. An upper limit, GM < 0.0031 km3 · sec-2, deduced by requiring that the orbital motion has a long lifetime in a realistic approximation to Ida's gravitational field, is illustrated with numerical calculations. Ida's mass is therefore constrained to the range 4.2 ± 0.6 × 1019 g, which, together with a volume of 16,100 ± 1900 km3 (Thomas P. C., M. J. S. Belton, B. Carcich, C. R. Chapman, M. E. Davies, R. Sullivan, and J. Veverka 1996. Icarus 120, 20-32.) yields a bulk density of 2.6 ± 0.5 g · cm-3 (Belton, M. J. S., C. R. Chapman, P. C. Thomas, M. E. Davies, R. Greenberg, K. Klaasen, D. Byrnes, L. D'Amario, S. Synnott, T. V. Johnson, A. McEwen, W. Merline, D. R. Davis, J-M. Petit, A. Storrs, J. Veverka, and B. Zellner 1995. Nature 374, 785-788.).

Original languageEnglish (US)
Pages (from-to)185-199
Number of pages15
JournalIcarus
Volume120
Issue number1
DOIs
StatePublished - Mar 1996

Fingerprint

natural satellites
orbits
asteroid
bulk density
perturbation
orbitals
encounters
gravitational fields
timescale
Ida asteroid
arcs
Galileo spacecraft
two body problem
playbacks
Hubble Space Telescope
inclination
brightness
gravitation
solid state
life (durability)

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Belton, M. J. S., Mueller, B. E. A., D'Amario, L. A., Byrnes, D. V., Klaasen, K. P., Synnott, S., ... Zellner, B. (1996). The discovery and orbit of 1993 (243)1 Dactyl. Icarus, 120(1), 185-199. https://doi.org/10.1006/icar.1996.0044

The discovery and orbit of 1993 (243)1 Dactyl. / Belton, Michael J S; Mueller, Beatrice E A; D'Amario, Louis A.; Byrnes, Dennis V.; Klaasen, Kenneth P.; Synnott, Steven; Breneman, Herbert; Johnson, Torrence V.; Thomas, Peter C.; Veverka, Joseph; Harch, Ann P.; Davies, Merton E.; Merline, William J.; Chapman, Clark R.; Davis, Donald; Denk, Tilmann; Neukum, Gerhard; Petit, Jean Marc; Greenberg, Richard J.; Storrs, Alex; Zellner, Benjamin.

In: Icarus, Vol. 120, No. 1, 03.1996, p. 185-199.

Research output: Contribution to journalArticle

Belton, MJS, Mueller, BEA, D'Amario, LA, Byrnes, DV, Klaasen, KP, Synnott, S, Breneman, H, Johnson, TV, Thomas, PC, Veverka, J, Harch, AP, Davies, ME, Merline, WJ, Chapman, CR, Davis, D, Denk, T, Neukum, G, Petit, JM, Greenberg, RJ, Storrs, A & Zellner, B 1996, 'The discovery and orbit of 1993 (243)1 Dactyl', Icarus, vol. 120, no. 1, pp. 185-199. https://doi.org/10.1006/icar.1996.0044
Belton MJS, Mueller BEA, D'Amario LA, Byrnes DV, Klaasen KP, Synnott S et al. The discovery and orbit of 1993 (243)1 Dactyl. Icarus. 1996 Mar;120(1):185-199. https://doi.org/10.1006/icar.1996.0044
Belton, Michael J S ; Mueller, Beatrice E A ; D'Amario, Louis A. ; Byrnes, Dennis V. ; Klaasen, Kenneth P. ; Synnott, Steven ; Breneman, Herbert ; Johnson, Torrence V. ; Thomas, Peter C. ; Veverka, Joseph ; Harch, Ann P. ; Davies, Merton E. ; Merline, William J. ; Chapman, Clark R. ; Davis, Donald ; Denk, Tilmann ; Neukum, Gerhard ; Petit, Jean Marc ; Greenberg, Richard J. ; Storrs, Alex ; Zellner, Benjamin. / The discovery and orbit of 1993 (243)1 Dactyl. In: Icarus. 1996 ; Vol. 120, No. 1. pp. 185-199.
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abstract = "Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida-Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate features being consistent with radiation hits. We deduce a manifold of osculating two-body orbits that approximate Dactyl's motion over the observed orbital arc depending on the assumed mass of Ida. At the time of Galileo's encounter, Dactyl was found to be 85 km from the center of Ida, moving at ∼6 m · sec-1 in the same direction as Ida's retrograde spin. The inclination of its orbit is ∼172° in Ida's equatorial system (IAU definition). It was not possible to obtain a definitive orbit or measure of Ida's mass from the observed motion even though supplemental techniques (search for Dactyl's shadow on Ida, changes in angular diameter and brightness, and attempts to determine the spin of Dactyl) were explored. The influence of Ida's irregular gravitational field and solar perturbations on two-body motion are evaluated and found to be undetectable in the observed orbital arc. These effects may, however, strongly influence the motion over orbital time scales. Limits to the value of Ida's gravitation parameter, GM, are derived. A robust lower limit, GM > 0.0023 km3 · sec-2, is obtained by requiring Dactyl's orbit to be bound. Hubble Space Telescope observations, which show no evidence of Dactyl on a hyperbolic orbit, excludes values of GM in the range 0.00216 < GM < 0.0023 km3 · sec-2. An upper limit, GM < 0.0031 km3 · sec-2, deduced by requiring that the orbital motion has a long lifetime in a realistic approximation to Ida's gravitational field, is illustrated with numerical calculations. Ida's mass is therefore constrained to the range 4.2 ± 0.6 × 1019 g, which, together with a volume of 16,100 ± 1900 km3 (Thomas P. C., M. J. S. Belton, B. Carcich, C. R. Chapman, M. E. Davies, R. Sullivan, and J. Veverka 1996. Icarus 120, 20-32.) yields a bulk density of 2.6 ± 0.5 g · cm-3 (Belton, M. J. S., C. R. Chapman, P. C. Thomas, M. E. Davies, R. Greenberg, K. Klaasen, D. Byrnes, L. D'Amario, S. Synnott, T. V. Johnson, A. McEwen, W. Merline, D. R. Davis, J-M. Petit, A. Storrs, J. Veverka, and B. Zellner 1995. Nature 374, 785-788.).",
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T1 - The discovery and orbit of 1993 (243)1 Dactyl

AU - Belton, Michael J S

AU - Mueller, Beatrice E A

AU - D'Amario, Louis A.

AU - Byrnes, Dennis V.

AU - Klaasen, Kenneth P.

AU - Synnott, Steven

AU - Breneman, Herbert

AU - Johnson, Torrence V.

AU - Thomas, Peter C.

AU - Veverka, Joseph

AU - Harch, Ann P.

AU - Davies, Merton E.

AU - Merline, William J.

AU - Chapman, Clark R.

AU - Davis, Donald

AU - Denk, Tilmann

AU - Neukum, Gerhard

AU - Petit, Jean Marc

AU - Greenberg, Richard J.

AU - Storrs, Alex

AU - Zellner, Benjamin

PY - 1996/3

Y1 - 1996/3

N2 - Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida-Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate features being consistent with radiation hits. We deduce a manifold of osculating two-body orbits that approximate Dactyl's motion over the observed orbital arc depending on the assumed mass of Ida. At the time of Galileo's encounter, Dactyl was found to be 85 km from the center of Ida, moving at ∼6 m · sec-1 in the same direction as Ida's retrograde spin. The inclination of its orbit is ∼172° in Ida's equatorial system (IAU definition). It was not possible to obtain a definitive orbit or measure of Ida's mass from the observed motion even though supplemental techniques (search for Dactyl's shadow on Ida, changes in angular diameter and brightness, and attempts to determine the spin of Dactyl) were explored. The influence of Ida's irregular gravitational field and solar perturbations on two-body motion are evaluated and found to be undetectable in the observed orbital arc. These effects may, however, strongly influence the motion over orbital time scales. Limits to the value of Ida's gravitation parameter, GM, are derived. A robust lower limit, GM > 0.0023 km3 · sec-2, is obtained by requiring Dactyl's orbit to be bound. Hubble Space Telescope observations, which show no evidence of Dactyl on a hyperbolic orbit, excludes values of GM in the range 0.00216 < GM < 0.0023 km3 · sec-2. An upper limit, GM < 0.0031 km3 · sec-2, deduced by requiring that the orbital motion has a long lifetime in a realistic approximation to Ida's gravitational field, is illustrated with numerical calculations. Ida's mass is therefore constrained to the range 4.2 ± 0.6 × 1019 g, which, together with a volume of 16,100 ± 1900 km3 (Thomas P. C., M. J. S. Belton, B. Carcich, C. R. Chapman, M. E. Davies, R. Sullivan, and J. Veverka 1996. Icarus 120, 20-32.) yields a bulk density of 2.6 ± 0.5 g · cm-3 (Belton, M. J. S., C. R. Chapman, P. C. Thomas, M. E. Davies, R. Greenberg, K. Klaasen, D. Byrnes, L. D'Amario, S. Synnott, T. V. Johnson, A. McEwen, W. Merline, D. R. Davis, J-M. Petit, A. Storrs, J. Veverka, and B. Zellner 1995. Nature 374, 785-788.).

AB - Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida-Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate features being consistent with radiation hits. We deduce a manifold of osculating two-body orbits that approximate Dactyl's motion over the observed orbital arc depending on the assumed mass of Ida. At the time of Galileo's encounter, Dactyl was found to be 85 km from the center of Ida, moving at ∼6 m · sec-1 in the same direction as Ida's retrograde spin. The inclination of its orbit is ∼172° in Ida's equatorial system (IAU definition). It was not possible to obtain a definitive orbit or measure of Ida's mass from the observed motion even though supplemental techniques (search for Dactyl's shadow on Ida, changes in angular diameter and brightness, and attempts to determine the spin of Dactyl) were explored. The influence of Ida's irregular gravitational field and solar perturbations on two-body motion are evaluated and found to be undetectable in the observed orbital arc. These effects may, however, strongly influence the motion over orbital time scales. Limits to the value of Ida's gravitation parameter, GM, are derived. A robust lower limit, GM > 0.0023 km3 · sec-2, is obtained by requiring Dactyl's orbit to be bound. Hubble Space Telescope observations, which show no evidence of Dactyl on a hyperbolic orbit, excludes values of GM in the range 0.00216 < GM < 0.0023 km3 · sec-2. An upper limit, GM < 0.0031 km3 · sec-2, deduced by requiring that the orbital motion has a long lifetime in a realistic approximation to Ida's gravitational field, is illustrated with numerical calculations. Ida's mass is therefore constrained to the range 4.2 ± 0.6 × 1019 g, which, together with a volume of 16,100 ± 1900 km3 (Thomas P. C., M. J. S. Belton, B. Carcich, C. R. Chapman, M. E. Davies, R. Sullivan, and J. Veverka 1996. Icarus 120, 20-32.) yields a bulk density of 2.6 ± 0.5 g · cm-3 (Belton, M. J. S., C. R. Chapman, P. C. Thomas, M. E. Davies, R. Greenberg, K. Klaasen, D. Byrnes, L. D'Amario, S. Synnott, T. V. Johnson, A. McEwen, W. Merline, D. R. Davis, J-M. Petit, A. Storrs, J. Veverka, and B. Zellner 1995. Nature 374, 785-788.).

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