Cometary Dust

Levasseur-Regourd, A. C.; Agarwal, Jessica; Cottin, Hervé; Engrand, C.; Flynn, G. J.; Fulle, M.; Gombosi, T. I.; Langevin, Y.; Lasue, J.; Mannel, Thurid; Merouane, S.; Poch, Olivier; Thomas, N.; Westphal, A. J.

doi:10.1007/s11214-018-0496-3

Cited by 107 publications

(91 citation statements)

References 324 publications

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“…This ratio is about a factor of 2 larger than the Fe/Ni ratio of 18 in CI chondrites (Asplund et al, 2009). Since Ni mainly resides in meteorites as Ni-Fe-S grains, which melt at a lower temperature than the Fe-containing silicate phase (Levasseur-Regourd et al, 2018), it is unlikely that Ni will ablate less efficiently than Fe. Therefore, the twofold depletion of Ni indicates that Ni is more efficiently sequestered as Ni + or neutral reservoir species, compared with Fe.…”

Section: Discussionmentioning

confidence: 85%

“…A typical Fe column abundance in January-March at midlatitudes is 1.5 · 10 10 cm −2 (Kane & Gardner, 1993), which implies a Fe/Ni ratio around 38. Since Ni mainly resides in meteorites as Ni-Fe-S grains, which melt at a lower temperature than the Fe-containing silicate phase (Levasseur-Regourd et al, 2018), it is unlikely that Ni will ablate less efficiently than Fe. Since Ni mainly resides in meteorites as Ni-Fe-S grains, which melt at a lower temperature than the Fe-containing silicate phase (Levasseur-Regourd et al, 2018), it is unlikely that Ni will ablate less efficiently than Fe.…”

Section: Discussionmentioning

confidence: 99%

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Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions

Gerding

Daly

Plane

2019

Geophysical Research Letters

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During six nights between January and March 2018 we observed the mesospheric Ni layer by lidar from Kühlungsborn, Germany (54°N, 12°E). For most of the soundings we utilized for the first time a transition from the low‐lying excited Ni(3D) state at 341 nm. For additional soundings we used the ground‐state Ni(3F) transition at 337 nm, giving similar results but a worse signal‐to‐noise ratio. We observed nightly mean Ni peak densities between ∼280 and 450 cm−3 and column abundances between 3.1·108 and 4.9·108 cm−2. Comparing with iron densities we get a Fe/Ni ratio of 38, which is a factor of 2 larger than the ratio in CI chondrites and factor of 32 larger than the Fe/Ni ratio observed by the only previous measurement of mesospheric Ni (Collins et al., 2015, https://doi.org/10.1002/2014GL062716). The underabundance of Ni compared to CI chondrites suggests that Ni is more efficiently sequestered as Ni+ or neutral reservoir species than Fe.

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Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions

Gerding

Daly

Plane

2019

Geophysical Research Letters

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“…The dust particles ejected from the nucleus of comet 67P/Churyumov-Gerasimenko (thereafter 67P/C-G), indeed one JFC, have been studied from the ESA Rosetta rendezvous spacecraft, which orbited the nucleus of 67P/C-G in 2014-2016, from 13 months before its perihelion passage to 13 months after it, as reviewed in Levasseur-Regourd et al (2018).…”

Section: Properties Of Near-earth Tiny Meteoroids a Post Rosetta Appmentioning

confidence: 99%

“…Secondly, their morphologies and porous structures allow their temperatures to remain low enough so that significant amounts of organics may survive in the atmosphere; fluffy aggregates may indeed bring up to π 3 times more material in volume without being ablated to the Earth's surface than compact spherical particles (see Fig. 10, Levasseur-Regourd et al 2018).…”

Section: Comparison With Cosmic Dust Particles Collected In the Stratmentioning

confidence: 99%

Linking studies of tiny meteoroids, zodiacal dust, cometary dust and circumstellar disks

Levasseur-Regourd

Lasue

Milli

et al. 2020

Planetary and Space Science

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Tiny meteoroids entering the Earth's atmosphere and inducing meteor showers have long been thought to originate partly from cometary dust. Together with other dust particles, they form a huge cloud around the Sun, the zodiacal cloud. From our previous studies of the zodiacal light, as well as other independent methods (dynamical studies, infrared observations, data related to Earth's environment), it is now established that a significant fraction of dust particles entering the Earth's atmosphere comes from Jupiterfamily comets (JFCs).This paper relies on our understanding of key properties of the zodiacal cloud and of comet 67P/Churyumov-Gerasimenko, extensively studied by the Rosetta mission to a JFC. The interpretation, through numerical and experimental simulations of zodiacal light local polarimetric phase curves, has recently allowed us to establish that interplanetary dust is rich in absorbing organics and consists of fluffy particles. The ground-truth provided by Rosetta presently establishes that the cometary dust particles are rich in organic compounds and consist of quite fluffy and irregular aggregates. Our aims are as follows: (1) to make links, back in time, between peculiar micrometeorites, tiny meteoroids, interplanetary dust particles, cometary dust particles, and the early evolution of the Solar System, and (2) to show how detailed studies of such meteoroids and of cometary dust particles can improve the interpretation of observations of dust in protoplanetary and debris disks. Future modeling of dust in such disks should favor irregular porous particles instead of more conventional compact spherical particles.

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“…What is common between very different objects, such as interstellar dust, protoplanetary discs [1-3], comets [4] and dust devils on Mars [5], Earth [6] and possibly other planets? All these systems are comprised of size and mass polydisperse dust particles immersed in molecular gas.…”

Section: Introductionmentioning

confidence: 99%

Size-polydisperse dust in molecular gas: Energy equipartition versus nonequipartition

2020

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We investigate numerically and analytically size-polydisperse granular mixtures immersed into a molecular gas. We show that the equipartition of granular temperatures of particles of different sizes is established; however, the granular temperatures significantly differ from the temperature of the molecular gas. This result is surprising since, generally, the energy equipartition is strongly violated in driven granular mixtures. Qualitatively, the obtained results do not depend on the collision model, being valid for a constant restitution coefficient ε, as well as for the ε for viscoelastic particles. Our findings may be important for astrophysical applications, such as protoplanetary disks, interstellar dust clouds, and comets.

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Cometary Dust

Cited by 107 publications

References 324 publications

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions

Linking studies of tiny meteoroids, zodiacal dust, cometary dust and circumstellar disks

Size-polydisperse dust in molecular gas: Energy equipartition versus nonequipartition

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Cometary Dust

Cited by 107 publications

References 324 publications

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(3F) and Ni(3D) Transitions

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(3F) and Ni(3D) Transitions

Linking studies of tiny meteoroids, zodiacal dust, cometary dust and circumstellar disks

Size-polydisperse dust in molecular gas: Energy equipartition versus nonequipartition

Contact Info

Product

Resources

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Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(³F) and Ni(³D) Transitions