First ENA observations at Mars: Solar-wind ENAs on the nightside

K. Brinkfeldt; H. Gunell; P. C. Brandt; S. Barabash; R. A. Frahm; J. D. Winningham; E. Kallio; M. Holmström; Y. Futaana; A. Ekenbäck; R. Lundin; H. Andersson; M. Yamauchi; A. Grigoriev; J. R. Sharber; J. R. Scherrer; A. J. Coates; D. R. Linder; D. O. Kataria; H. Koskinen; T. Säles; P. Riihelä; W. Schmidt; J. Kozyra; J. Luhmann; E. Roelof; D. Williams; S. Livi; C. C. Curtis; K. C. Hsieh; B. R. Sandel; M. Grande; M. Carter; J. A. Sauvaud; A. Fedorov; J. J. Thocaven; S. McKenna-Lawler; S. Orsini; R. Cerulli-Irelli; M. Maggi; P. Wurz; P. Bochsler; N. Krupp; J. Woch; M. Fränz; K. Asamura; C. Dierker

doi:10.1016/j.icarus.2005.12.023

First ENA observations at Mars: Solar-wind ENAs on the nightside

K. Brinkfeldt^*, H. Gunell, P. C. Brandt, S. Barabash, R. A. Frahm, J. D. Winningham, E. Kallio, M. Holmström, Y. Futaana, A. Ekenbäck, R. Lundin, H. Andersson, M. Yamauchi, A. Grigoriev, J. R. Sharber, J. R. Scherrer, A. J. Coates, D. R. Linder, D. O. Kataria, H. KoskinenT. Säles, P. Riihelä, W. Schmidt, J. Kozyra, J. Luhmann, E. Roelof, D. Williams, S. Livi, C. C. Curtis, K. C. Hsieh, B. R. Sandel, M. Grande, M. Carter, J. A. Sauvaud, A. Fedorov, J. J. Thocaven, S. McKenna-Lawler, S. Orsini, R. Cerulli-Irelli, M. Maggi, P. Wurz, P. Bochsler, N. Krupp, J. Woch, M. Fränz, K. Asamura, C. Dierker

^*Corresponding author for this work

Department of Physics

Research output: Contribution to journal › Article › peer-review

26 Citations (Scopus)

Abstract

We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direction for several minutes as the spacecraft moves into the eclipse. However, our ENA imager is also sensitive to UV photons and we compare the measurements to ENA simulations and a simplified model of UV scattering in the exosphere. Simulations and further comparisons with an electron spectrometer sensitive to photoelectrons generated when UV photons interact with the spacecraft suggest that what we are seeing in Mars' eclipse are ENAs from upstream of the bow shock produced in charge exchange with solar wind ions with a non-zero temperature. The measurements are a precursor to a new technique called ENA sounding to measure solar wind and planetary exosphere properties in the future.

Original language	English
Pages (from-to)	439-447
Number of pages	9
Journal	Icarus
Volume	182
Issue number	2
DOIs	https://doi.org/10.1016/j.icarus.2005.12.023
Publication status	Published - Jun 2006

Keywords

Magnetospheres
Mars
Solar wind

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Brinkfeldt, K., Gunell, H., Brandt, P. C., Barabash, S., Frahm, R. A., Winningham, J. D., Kallio, E., Holmström, M., Futaana, Y., Ekenbäck, A., Lundin, R., Andersson, H., Yamauchi, M., Grigoriev, A., Sharber, J. R., Scherrer, J. R., Coates, A. J., Linder, D. R., Kataria, D. O., ... Dierker, C. (2006). First ENA observations at Mars: Solar-wind ENAs on the nightside. Icarus, 182(2), 439-447. https://doi.org/10.1016/j.icarus.2005.12.023

@article{33dcd5f366a04bcfbd21f2bf35fc3cb8,

title = "First ENA observations at Mars: Solar-wind ENAs on the nightside",

abstract = "We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direction for several minutes as the spacecraft moves into the eclipse. However, our ENA imager is also sensitive to UV photons and we compare the measurements to ENA simulations and a simplified model of UV scattering in the exosphere. Simulations and further comparisons with an electron spectrometer sensitive to photoelectrons generated when UV photons interact with the spacecraft suggest that what we are seeing in Mars' eclipse are ENAs from upstream of the bow shock produced in charge exchange with solar wind ions with a non-zero temperature. The measurements are a precursor to a new technique called ENA sounding to measure solar wind and planetary exosphere properties in the future.",

keywords = "Magnetospheres, Mars, Solar wind",

author = "K. Brinkfeldt and H. Gunell and Brandt, {P. C.} and S. Barabash and Frahm, {R. A.} and Winningham, {J. D.} and E. Kallio and M. Holmstr{\"o}m and Y. Futaana and A. Ekenb{\"a}ck and R. Lundin and H. Andersson and M. Yamauchi and A. Grigoriev and Sharber, {J. R.} and Scherrer, {J. R.} and Coates, {A. J.} and Linder, {D. R.} and Kataria, {D. O.} and H. Koskinen and T. S{\"a}les and P. Riihel{\"a} and W. Schmidt and J. Kozyra and J. Luhmann and E. Roelof and D. Williams and S. Livi and Curtis, {C. C.} and Hsieh, {K. C.} and Sandel, {B. R.} and M. Grande and M. Carter and Sauvaud, {J. A.} and A. Fedorov and Thocaven, {J. J.} and S. McKenna-Lawler and S. Orsini and R. Cerulli-Irelli and M. Maggi and P. Wurz and P. Bochsler and N. Krupp and J. Woch and M. Fr{\"a}nz and K. Asamura and C. Dierker",

note = "Funding Information: The ASPERA-3 experiment on the European Space Agency (ESA) Mars Express mission is a joint effort between 15 laboratories in 10 countries, all sponsored by their national agencies. We thank all these agencies as well as the various departments/institutes hosting these efforts. This work was partially supported by the Swedish National Graduate School of Space Technology. Support for the Electron Spectrometer design, construction, operation and data analysis of the ASPERA-3 data was provided by NASA Contract NASW00003. We also acknowledge the Swedish National Space Board for their support of the main PI-institute and we are indebted to ESA for their courage in embarking on the Mars Express program, the first ESA mission to the red planet. Copyright: Copyright 2006 Elsevier B.V., All rights reserved.",

year = "2006",

month = jun,

doi = "10.1016/j.icarus.2005.12.023",

language = "English",

volume = "182",

pages = "439--447",

journal = "Icarus",

issn = "0019-1035",

publisher = "Elsevier",

number = "2",

}

Brinkfeldt, K, Gunell, H, Brandt, PC, Barabash, S, Frahm, RA, Winningham, JD, Kallio, E, Holmström, M, Futaana, Y, Ekenbäck, A, Lundin, R, Andersson, H, Yamauchi, M, Grigoriev, A, Sharber, JR, Scherrer, JR, Coates, AJ, Linder, DR, Kataria, DO, Koskinen, H, Säles, T, Riihelä, P, Schmidt, W, Kozyra, J, Luhmann, J, Roelof, E, Williams, D, Livi, S, Curtis, CC, Hsieh, KC, Sandel, BR, Grande, M, Carter, M, Sauvaud, JA, Fedorov, A, Thocaven, JJ, McKenna-Lawler, S, Orsini, S, Cerulli-Irelli, R, Maggi, M, Wurz, P, Bochsler, P, Krupp, N, Woch, J, Fränz, M, Asamura, K & Dierker, C 2006, 'First ENA observations at Mars: Solar-wind ENAs on the nightside', Icarus, vol. 182, no. 2, pp. 439-447. https://doi.org/10.1016/j.icarus.2005.12.023

TY - JOUR

T1 - First ENA observations at Mars

T2 - Solar-wind ENAs on the nightside

AU - Brinkfeldt, K.

AU - Gunell, H.

AU - Brandt, P. C.

AU - Barabash, S.

AU - Frahm, R. A.

AU - Winningham, J. D.

AU - Kallio, E.

AU - Holmström, M.

AU - Futaana, Y.

AU - Ekenbäck, A.

AU - Lundin, R.

AU - Andersson, H.

AU - Yamauchi, M.

AU - Grigoriev, A.

AU - Sharber, J. R.

AU - Scherrer, J. R.

AU - Coates, A. J.

AU - Linder, D. R.

AU - Kataria, D. O.

AU - Koskinen, H.

AU - Säles, T.

AU - Riihelä, P.

AU - Schmidt, W.

AU - Kozyra, J.

AU - Luhmann, J.

AU - Roelof, E.

AU - Williams, D.

AU - Livi, S.

AU - Curtis, C. C.

AU - Hsieh, K. C.

AU - Sandel, B. R.

AU - Grande, M.

AU - Carter, M.

AU - Sauvaud, J. A.

AU - Fedorov, A.

AU - Thocaven, J. J.

AU - McKenna-Lawler, S.

AU - Orsini, S.

AU - Cerulli-Irelli, R.

AU - Maggi, M.

AU - Wurz, P.

AU - Bochsler, P.

AU - Krupp, N.

AU - Woch, J.

AU - Fränz, M.

AU - Asamura, K.

AU - Dierker, C.

N1 - Funding Information: The ASPERA-3 experiment on the European Space Agency (ESA) Mars Express mission is a joint effort between 15 laboratories in 10 countries, all sponsored by their national agencies. We thank all these agencies as well as the various departments/institutes hosting these efforts. This work was partially supported by the Swedish National Graduate School of Space Technology. Support for the Electron Spectrometer design, construction, operation and data analysis of the ASPERA-3 data was provided by NASA Contract NASW00003. We also acknowledge the Swedish National Space Board for their support of the main PI-institute and we are indebted to ESA for their courage in embarking on the Mars Express program, the first ESA mission to the red planet. Copyright: Copyright 2006 Elsevier B.V., All rights reserved.

PY - 2006/6

Y1 - 2006/6

N2 - We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direction for several minutes as the spacecraft moves into the eclipse. However, our ENA imager is also sensitive to UV photons and we compare the measurements to ENA simulations and a simplified model of UV scattering in the exosphere. Simulations and further comparisons with an electron spectrometer sensitive to photoelectrons generated when UV photons interact with the spacecraft suggest that what we are seeing in Mars' eclipse are ENAs from upstream of the bow shock produced in charge exchange with solar wind ions with a non-zero temperature. The measurements are a precursor to a new technique called ENA sounding to measure solar wind and planetary exosphere properties in the future.

AB - We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direction for several minutes as the spacecraft moves into the eclipse. However, our ENA imager is also sensitive to UV photons and we compare the measurements to ENA simulations and a simplified model of UV scattering in the exosphere. Simulations and further comparisons with an electron spectrometer sensitive to photoelectrons generated when UV photons interact with the spacecraft suggest that what we are seeing in Mars' eclipse are ENAs from upstream of the bow shock produced in charge exchange with solar wind ions with a non-zero temperature. The measurements are a precursor to a new technique called ENA sounding to measure solar wind and planetary exosphere properties in the future.

KW - Magnetospheres

KW - Mars

KW - Solar wind

UR - http://www.scopus.com/inward/record.url?scp=33747333648&partnerID=8YFLogxK

U2 - 10.1016/j.icarus.2005.12.023

DO - 10.1016/j.icarus.2005.12.023

M3 - Article

AN - SCOPUS:33747333648

SN - 0019-1035

VL - 182

SP - 439

EP - 447

JO - Icarus

JF - Icarus

IS - 2

ER -

First ENA observations at Mars: Solar-wind ENAs on the nightside

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