scholarly journals Celestial mechanics and polarization optics of the Kordylewski dust cloud in the Earth–Moon Lagrange point L5 – Part II. Imaging polarimetric observation: new evidence for the existence of Kordylewski dust cloud

2018 ◽  
Vol 482 (1) ◽  
pp. 762-770 ◽  
Author(s):  
Judit Slíz-Balogh ◽  
András Barta ◽  
Gábor Horváth
Keyword(s):  
Celestial Mechanics ◽  
Dust Cloud ◽  
Lagrange Point ◽  
Polarimetric Observation ◽  
The Earth ◽  
Polarization Optics ◽  
New Evidence

Destiny+ Dust Analyzer – Campaign & timeline preparation for interplanetary & interstellar dust observation during the 4-year transfer phase from Earth to Phaethon

2020 ◽  
Author(s):  
Maximilian Sommer ◽  
Harald Krüger ◽  
Ralf Srama ◽  
Takayuki Hirai ◽  
Masanori Kobayashi ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Interstellar Dust ◽  
Impact Ionization ◽  
Interplanetary Space ◽  
Dust Cloud ◽  
Dust Particles ◽  
Transfer Phase ◽  
Moon System ◽  
The Earth ◽  
The Impact

<p align="justify">The Destiny+ mission (Demonstration and Experiment of Space Technology for Interplanetary voyage Phaethon fLyby and dUst Science) has been selected as part of its M-class Space Science Program by the Japanese space agency JAXA/ISAS and is set to launch in 2023/2024. The mission target is the active asteroid (3200) Phaethon with a projected flyby in early 2028. The scientific payload consists of two cameras (the Telescopic Camera for Phaethon, TCAP, and the Multi-band Camera for Phaethon, MCAP), and the Destiny+ Dust Analyzer (DDA). DDA is the technological successor to the Cosmic Dust Analyzer (CDA) aboard Cassini-Huygens, which prominently investigated the dust environment of the Saturnian system. The DDA sensor is designed as a combination of impact ionization time-of-flight mass spectrometer and trajectory sensor, which will allow for the analysis of sub-micron and micron sized dust particles with respect to their composition (mass resolution m/Δm ≈ 100-150), mass, electrical charge, velocity (about 10% accuracy), and impact direction (about 10° accuracy).</p> <p align="justify">Besides attempting to sample the impact-generated dust cloud around Phaethon during the flyby, DDA will be actively observing the interplanetary & interstellar dust environment over the roughly four years spanning cruise phase from the Earth-Moon system through interplanetary space. After launch into a GTO-like orbit, Destiny+ will first employ its solar-electric propulsion system to spiral up to the lunar orbit within about 18 months, followed by a series of lunar swingbys and interim coasting phases in distant cislunar space, accumulating momentum to leave the Earth-Moon system at high excess velocity. The subsequent roughly 2-year interplanetary transfer to intercept Phaethon will be characterized by moderate orbital eccentricity of up to 0.1 and largely unpowered coasting phases.</p> <p align="justify">During these four years, the DDA sensor will benefit from a maximum pointing coverage range enabled by its dual-axis pointing mechanism and spacecraft attitude flexibility (during times of unpowered flight). This will allow for exhaustive mapping and analysis of the different interplanetary dust populations, as well as interstellar dust encountered in the region between 0.9-1.1 AU.</p> <p align="justify">Here, we give a progress report on the science planning efforts for the 4-year transfer phase. We present a tentative observation timeline that assigns scientific campaigns to different phases of the mission, taking into account results of various dust models, as well as operational and technical constraints.</p>

scholarly journals SIRTF: A Unique Opportunity for Probing the Zodiacal Cloud

1996 ◽  
Vol 150 ◽  
pp. 159-162
Author(s):  
Sumita Jayaraman ◽  
Stanley F. Dermott ◽  
Michael Werner
Keyword(s):  
Thermal Emission ◽  
Dust Cloud ◽  
Thermal Characteristics ◽  
Dust Particles ◽  
Infrared Telescope ◽  
The Earth ◽  
Telescope Facility ◽  
Asteroidal Dust ◽  
Infrared Telescope Facility ◽  
Dust Ring

AbstractThe Space Infrared Telescope Facility (SIRTF) is planned for launch by NASA in 2001 in a heliocentric orbit at 1.01 AU The spacecraft will drift away from the Earth slowly, reaching a distance of 0.3 AU behind the Earth at the end of its 2.5 year mission. This implies that SIRTF will spiral through the Earth's resonant dust ring (Wright et al., 1995) and, in particular, that it will traverse the dust cloud in the ring that trails the Earth in its orbit. We have used a dynamical model of the ring (Dermott et al., 1994) followed by simulation of the SIRTF orbit to predict the variations in the zodiacal thermal emission due to the trailing dust cloud as seen by SIRTF. Because the dust ring is inclined to the ecliptic, the latitude of peak flux of the trailing cloud will have yearly oscillations about the ecliptic. The amplitude of the oscillations will increase as SIRTF approaches the cloud, reaching a maximum of 20 during the mission. The magnitude of the flux variations can be as high as 4 – 5% or 2–3 MJy/Sr, SIRTF's measurements of these effects will allow us to model the number density and thermal characteristics of asteroidal dust particles near the Earth.

The Formation of Micro-Diamonds in Decompression-Cracks During the Uplift of the Kimberlite Controlled by the C:O:H Ratio in NAMS

2021 ◽  
Author(s):  
Holger Sommer ◽  
Dorrit Jacob ◽  
Klaus Regenauer-Lieb
Keyword(s):  
Planar Defect ◽  
Formation Mechanisms ◽  
Defect Structures ◽  
The Earth ◽  
Micro Cracks ◽  
Nitrogen Concentrations ◽  
Ft Ir ◽  
New Evidence ◽  
Ir And Raman ◽  
Bearing Part

<p>We show new evidence that natural micro-diamonds can be formed in decompression-cracks by C:O:H bearing volatiles in a bimineralic eclogite. The investigated rock sample is a heterogeneous kyanite- bearing and bimineralic eclogite from the Roberts Victor mine, South Africa. Kyanite reacts out in the kyanite bearing part of the sample, but metastable relics are still present within the bimineralic part of the rock. The presence of these metastable kyanite relicts, suggest very low fH2O during the phase transition from the kyanite- bearing into the bimineralic eclogite. High-spatial-resolution synchrotron based FT-IR and RAMAN spectroscopy have been used to detect C:O:H-bearing volatiles around micro diamonds in planar defect structures in garnet in the bimineralic parts of the sample and N concentration has been analyzed within the micro-diamonds. In micro-diamond-bearing planar defect structures, a correlation between C:O:H-bearing volatiles can be identified whereas in micro-diamond -ree planar defect structures no correlation of the different C:O:H containing volatiles was detected. We suggest that the micro-diamond forming reaction was triggered by water released by the breakdown of water-bearing kyanite. We propose that the C:O:H bearing volatiles acted as a catalyst, changing in composition with changing P-T conditions in the rock during metamorphism. This catalytic process leads to permanent modification of C:O:H ratios and under favourable thermodynamic, stoichiometric and kinetic conditions micro-diamonds can be formed. Nitrogen concentrations in the analyzed micro-diamonds suggest that the formation of the micro-diamonds took place shortly before the uplift of the eclogite from the Earth mantle to the surface. The conclusions from our study proves that C:O:H-bearing volatiles, and their distribution pattern around the investigated micro-cracks, are indicative of the formation mechanisms of micro-diamonds controlled by C:O:H bearing fluids rather than by the solid-solid transformation from graphite into diamond.</p>

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