First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno

F. Allegrini; G. R. Gladstone; V. Hue; G. Clark; J. R. Szalay; W. S. Kurth; F. Bagenal; S. Bolton; J. E.P. Connerney; R. W. Ebert; T. K. Greathouse; G. B. Hospodarsky; M. Imai; P. Louarn; B. H. Mauk; D. J. McComas; J. Saur; A. H. Sulaiman; P. W. Valek; R. J. Wilson

doi:10.1029/2020GL089732

First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno

F. Allegrini, G. R. Gladstone, V. Hue, G. Clark, J. R. Szalay, W. S. Kurth, F. Bagenal, S. Bolton, J. E.P. Connerney, R. W. Ebert, T. K. Greathouse, G. B. Hospodarsky, M. Imai, P. Louarn, B. H. Mauk, D. J. McComas, J. Saur, A. H. Sulaiman, P. W. Valek, R. J. Wilson

Astrophysical Sciences

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Abstract

We report the first in situ observations of electron measurements at a Europa footprint tail (FPT) crossing in the auroral region. During its 12th science perijove pass, Juno crossed magnetic field lines connected to Europa's FPT. We find that electrons in the range ~0.4 to ~25 keV, with a characteristic energy of 3.6 ± 0.5 keV, precipitate into Jupiter's atmosphere to create the footprint aurora. The energy flux peaks at ~36 mW/m², while the peak ultraviolet (UV) brightness is estimated at 37 kR. We estimate the peak electron density and temperature to be 17.3 cm⁻³ and 1.8 ± 0.1 keV, respectively. Using magnetic flux shell mapping, we estimate that the radial width of the interaction at Europa's orbit spans roughly 3.6 ± 1.0 Europa radii. In contrast to typical Io FPT crossings, the instrument background caused by penetrating energetic radiation (> ~5–10 MeV electrons) increased during the Europa FPT crossing.

Original language	English (US)
Article number	e2020GL089732
Journal	Geophysical Research Letters
Volume	47
Issue number	18
DOIs	https://doi.org/10.1029/2020GL089732
State	Published - Sep 28 2020

All Science Journal Classification (ASJC) codes

Geophysics
General Earth and Planetary Sciences

Keywords

Europa footprint tail
Jupiter aurora
electrons

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10.1029/2020GL089732

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Allegrini, F., Gladstone, G. R., Hue, V., Clark, G., Szalay, J. R., Kurth, W. S., Bagenal, F., Bolton, S., Connerney, J. E. P., Ebert, R. W., Greathouse, T. K., Hospodarsky, G. B., Imai, M., Louarn, P., Mauk, B. H., McComas, D. J., Saur, J., Sulaiman, A. H., Valek, P. W., & Wilson, R. J. (2020). First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno. Geophysical Research Letters, 47(18), Article e2020GL089732. https://doi.org/10.1029/2020GL089732

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title = "First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno",

abstract = "We report the first in situ observations of electron measurements at a Europa footprint tail (FPT) crossing in the auroral region. During its 12th science perijove pass, Juno crossed magnetic field lines connected to Europa's FPT. We find that electrons in the range ~0.4 to ~25 keV, with a characteristic energy of 3.6 ± 0.5 keV, precipitate into Jupiter's atmosphere to create the footprint aurora. The energy flux peaks at ~36 mW/m2, while the peak ultraviolet (UV) brightness is estimated at 37 kR. We estimate the peak electron density and temperature to be 17.3 cm−3 and 1.8 ± 0.1 keV, respectively. Using magnetic flux shell mapping, we estimate that the radial width of the interaction at Europa's orbit spans roughly 3.6 ± 1.0 Europa radii. In contrast to typical Io FPT crossings, the instrument background caused by penetrating energetic radiation (> ~5–10 MeV electrons) increased during the Europa FPT crossing.",

keywords = "Europa footprint tail, Jupiter aurora, electrons",

author = "F. Allegrini and Gladstone, {G. R.} and V. Hue and G. Clark and Szalay, {J. R.} and Kurth, {W. S.} and F. Bagenal and S. Bolton and Connerney, {J. E.P.} and Ebert, {R. W.} and Greathouse, {T. K.} and Hospodarsky, {G. B.} and M. Imai and P. Louarn and Mauk, {B. H.} and McComas, {D. J.} and J. Saur and Sulaiman, {A. H.} and Valek, {P. W.} and Wilson, {R. J.}",

year = "2020",

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doi = "10.1029/2020GL089732",

language = "English (US)",

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Allegrini, F, Gladstone, GR, Hue, V, Clark, G, Szalay, JR, Kurth, WS, Bagenal, F, Bolton, S, Connerney, JEP, Ebert, RW, Greathouse, TK, Hospodarsky, GB, Imai, M, Louarn, P, Mauk, BH, McComas, DJ, Saur, J, Sulaiman, AH, Valek, PW & Wilson, RJ 2020, 'First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno', Geophysical Research Letters, vol. 47, no. 18, e2020GL089732. https://doi.org/10.1029/2020GL089732

TY - JOUR

T1 - First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno

AU - Allegrini, F.

AU - Gladstone, G. R.

AU - Hue, V.

AU - Clark, G.

AU - Szalay, J. R.

AU - Kurth, W. S.

AU - Bagenal, F.

AU - Bolton, S.

AU - Connerney, J. E.P.

AU - Ebert, R. W.

AU - Greathouse, T. K.

AU - Hospodarsky, G. B.

AU - Imai, M.

AU - Louarn, P.

AU - Mauk, B. H.

AU - McComas, D. J.

AU - Saur, J.

AU - Sulaiman, A. H.

AU - Valek, P. W.

AU - Wilson, R. J.

PY - 2020/9/28

Y1 - 2020/9/28

N2 - We report the first in situ observations of electron measurements at a Europa footprint tail (FPT) crossing in the auroral region. During its 12th science perijove pass, Juno crossed magnetic field lines connected to Europa's FPT. We find that electrons in the range ~0.4 to ~25 keV, with a characteristic energy of 3.6 ± 0.5 keV, precipitate into Jupiter's atmosphere to create the footprint aurora. The energy flux peaks at ~36 mW/m2, while the peak ultraviolet (UV) brightness is estimated at 37 kR. We estimate the peak electron density and temperature to be 17.3 cm−3 and 1.8 ± 0.1 keV, respectively. Using magnetic flux shell mapping, we estimate that the radial width of the interaction at Europa's orbit spans roughly 3.6 ± 1.0 Europa radii. In contrast to typical Io FPT crossings, the instrument background caused by penetrating energetic radiation (> ~5–10 MeV electrons) increased during the Europa FPT crossing.

AB - We report the first in situ observations of electron measurements at a Europa footprint tail (FPT) crossing in the auroral region. During its 12th science perijove pass, Juno crossed magnetic field lines connected to Europa's FPT. We find that electrons in the range ~0.4 to ~25 keV, with a characteristic energy of 3.6 ± 0.5 keV, precipitate into Jupiter's atmosphere to create the footprint aurora. The energy flux peaks at ~36 mW/m2, while the peak ultraviolet (UV) brightness is estimated at 37 kR. We estimate the peak electron density and temperature to be 17.3 cm−3 and 1.8 ± 0.1 keV, respectively. Using magnetic flux shell mapping, we estimate that the radial width of the interaction at Europa's orbit spans roughly 3.6 ± 1.0 Europa radii. In contrast to typical Io FPT crossings, the instrument background caused by penetrating energetic radiation (> ~5–10 MeV electrons) increased during the Europa FPT crossing.

KW - Europa footprint tail

KW - Jupiter aurora

KW - electrons

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DO - 10.1029/2020GL089732

M3 - Article

AN - SCOPUS:85091476969

SN - 0094-8276

VL - 47

JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 18

M1 - e2020GL089732

ER -

First Report of Electron Measurements During a Europa Footprint Tail Crossing by Juno

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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