On the physical origin of the homochirality of life

2005 ◽  
Vol 13 (S2) ◽  
pp. 49-59 ◽  
Author(s):  
DAVID B. CLINE
Keyword(s):  
Space Missions ◽  
Racemic Mixture ◽  
Physical Origin ◽  
Physical Mechanisms ◽  
The Earth ◽  
Future Space ◽  
The Galaxy

It seems to be well known that life cannot arise in a racemic mixture of molecules (L=D). The various physical mechanisms that could influence the homochirality of the molecules responsible for life are reviewed together with a model where these molecules might be produced in the galaxy prior to the formation of the earth. The focus is on the influence of a powerful supernovae explosion to affect the homochirality of these molecules. Possible tests of this concept with meteorites and future space missions are described.

scholarly journals 2.1.1 In-Situ Records of Interplanetary Dust Particles - Methods and Results

1976 ◽  
Vol 31 ◽  
pp. 143-158 ◽  
Author(s):  
H. Fechtig
Keyword(s):  
Interplanetary Dust ◽  
Space Missions ◽  
Dust Particles ◽  
Measure Data ◽  
Interplanetary Dust Particles ◽  
Detection Techniques ◽  
The Earth ◽  
Future Space

AbstractA review is given on the techniques used to record and to quantitatively measure data of individual interplanetary dust particles. New developments in detection techniques are briefly discussed.The main results from recent space missions at about 1 AU and in the earth-moon neighborhood are discussed and compared with the flux results from lunar microcrater studies. Spatial anisotropies and time fluctuations are found indicating that the earth is exposed to two main micrometeoroid dust populations: the “apex”-population and the B-meteoroids. The near planet-dust enrichments measured by HEOS 2 near the earth and by the Pioneer 10/11 near Jupiter are emphasized. The experimental data strongly suggest a fragmentation process associated with the earth. The role of the moon as a dust source is discussed. The important problems in the dust field for future space missions are summarized.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

scholarly journals Using supraglottic airways by paramedics for airway management in analogue microgravity increases speed and success of ventilation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jochen Hinkelbein ◽  
Anton Ahlbäck ◽  
Christine Antwerber ◽  
Lisa Dauth ◽  
James DuCanto ◽  
...  
Keyword(s):  
Airway Management ◽  
Success Rate ◽  
Simulated Microgravity ◽  
Laryngeal Tube ◽  
Space Missions ◽  
Airway Device ◽  
Future Space ◽  
Secondary Endpoints ◽  
Present Trial

AbstractIn the next few years, the number of long-term space missions will significantly increase. Providing safe concepts for emergencies including airway management will be a highly challenging task. The aim of the present trial is to compare different airway management devices in simulated microgravity using a free-floating underwater scenario. Five different devices for airway management [laryngeal mask (LM), laryngeal tube (LT), I-GEL, direct laryngoscopy (DL), and video laryngoscopy (VL)] were compared by n = 20 paramedics holding a diving certificate in a randomized cross-over setting both under free-floating conditions in a submerged setting (pool, microgravity) and on ground (normogravity). The primary endpoint was the successful placement of the airway device. The secondary endpoints were the number of attempts and the time to ventilation. A total of 20 paramedics (3 female, 17 male) participated in this study. Success rate was highest for LM and LT and was 100% both during simulated microgravity and normogravity followed by the I-GEL (90% during microgravity and 95% during normogravity). However, the success rate was less for both DL (60% vs. 95%) and VL (20% vs. 60%). Fastest ventilation was performed with the LT both in normogravity (13.7 ± 5.3 s; n = 20) and microgravity (19.5 ± 6.1 s; n = 20). For the comparison of normogravity and microgravity, time to ventilation was shorter for all devices on the ground (normogravity) as compared underwater (microgravity). In the present study, airway management with supraglottic airways and laryngoscopy was shown to be feasible. Concerning the success rate and time to ventilation, the optimum were supraglottic airways (LT, LM, I-GEL) as their placement was faster and associated with a higher success rate. For future space missions, the use of supraglottic airways for airway management seems to be more promising as compared to tracheal intubation by DL or VL.

scholarly journals On particle acceleration and transport in plasmas in the Galaxy: theory and observations

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
Elena Amato ◽  
Sabrina Casanova
Keyword(s):  
Particle Acceleration ◽  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Energetic Particles ◽  
Quality Data ◽  
Current Status ◽  
The Earth ◽  
The Galaxy ◽  
Formation And Evolution ◽  
Galaxy Assembly

Accelerated particles are ubiquitous in the Cosmos and play a fundamental role in many processes governing the evolution of the Universe at all scales, from the sub-AU scale relevant for the formation and evolution of stars and planets to the Mpc scale involved in Galaxy assembly. We reveal the presence of energetic particles in many classes of astrophysical sources thanks to their production of non-thermal radiation, and we detect them directly at the Earth as cosmic rays. In the last two decades both direct and indirect observations have provided us a wealth of new, high-quality data about cosmic rays and their interactions both in sources and during propagation, in the Galaxy and in the Solar System. Some of the new data have confirmed existing theories about particle acceleration and propagation and their interplay with the environment in which they occur. Some others have brought about interesting surprises, whose interpretation is not straightforward within the standard framework and may require a change of paradigm in terms of our ideas about the origin of cosmic rays of different species or in different energy ranges. In this article, we focus on cosmic rays of galactic origin, namely with energies below a few petaelectronvolts, where a steepening is observed in the spectrum of energetic particles detected at the Earth. We review the recent observational findings and the current status of the theory about the origin and propagation of galactic cosmic rays.

scholarly journals Tidal interactions in rotating multiple stars and their impact on their evolution

2014 ◽  
Vol 9 (S307) ◽  
pp. 208-210
Author(s):  
P. Auclair-Desrotour ◽  
S. Mathis ◽  
C. Le Poncin-Lafitte
Keyword(s):  
Fluid Model ◽  
Orbital Evolution ◽  
Tidal Dissipation ◽  
Tidal Waves ◽  
Physical Mechanisms ◽  
Tidal Interactions ◽  
The Earth ◽  
Half Height ◽  
Multiple Stars ◽  
Stellar Interiors

AbstractTidal dissipation in stars is one of the key physical mechanisms that drive the evolution of binary and multiple stars. As in the Earth oceans, it corresponds to the resonant excitation of their eigenmodes of oscillation and their damping. Therefore, it strongly depends on the internal structure, rotation, and dissipative mechanisms in each component. In this work, we present a local analytical modeling of tidal gravito-inertial waves excited in stellar convective and radiative regions respectively. This model allows us to understand in details the properties of the resonant tidal dissipation as a function of the excitation frequencies, the rotation, the stratification, and the viscous and thermal properties of the studied fluid regions. Then, the frequencies, height, width at half-height, and number of resonances as well as the non-resonant equilibrium tide are derived analytically in asymptotic regimes that are relevant in stellar interiors. Finally, we demonstrate how viscous dissipation of tidal waves leads to a strongly erratic orbital evolution in the case of a coplanar binary system. We characterize such a non-regular dynamics as a function of the height and width of resonances, which have been previously characterized thanks to our local fluid model.

Development of double-stage ADR for future space missions

Cryogenics ◽  
2010 ◽  
Vol 50 (9) ◽  
pp. 597-602 ◽  
Author(s):  
Keisuke Shinozaki ◽  
Kazuhisa Mitsuda ◽  
Noriko Y. Yamasaki ◽  
Yoh Takei ◽  
Kensuke Masui ◽  
...  
Keyword(s):  
Space Missions ◽  
Future Space

scholarly journals Research and Development of Heat Switch for Future Space Missions

2014 ◽  
Vol 12 (ists29) ◽  
pp. Po_4_7-Po_4_11
Author(s):  
Keisuke SHINOZAKI ◽  
Takehiro NOHARA ◽  
Makiko ANDO ◽  
Atsushi OKAMOTO ◽  
Masakatsu MAEDA ◽  
...  
Keyword(s):  
Research And Development ◽  
Space Missions ◽  
Future Space

scholarly journals Past, Present, and Future of the Scaling Relations of Galaxies and Active Galactic Nuclei

2021 ◽  
Vol 8 ◽  
Author(s):  
Mauro D’Onofrio ◽  
Paola Marziani ◽  
Cesare Chiosi
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Formation ◽  
Galactic Nuclei ◽  
Scaling Relations ◽  
Short History ◽  
Physical Mechanisms ◽  
Galaxy Formation And Evolution ◽  
The Galaxy ◽  
History Of ◽  
Formation And Evolution

We review the properties of the established Scaling Relations (SRs) of galaxies and active galactic nuclei (AGN), focusing on their origin and expected evolution back in time, providing a short history of the most important progresses obtained up to now and discussing the possible future studies. We also try to connect the observed SRs with the physical mechanisms behind them, examining to what extent current models reproduce the observational data. The emerging picture clarifies the complexity intrinsic to the galaxy formation and evolution process as well as the basic uncertainties still affecting our knowledge of the AGN phenomenon. At the same time, however, it suggests that the detailed analysis of the SRs can profitably contribute to our understanding of galaxies and AGN.

scholarly journals SDSS-IV MaNGA: galaxy gas-phase metallicity gradients vary across the mass–size plane

2020 ◽  
Vol 501 (1) ◽  
pp. 948-953
Author(s):  
N F Boardman ◽  
G Zasowski ◽  
J A Newman ◽  
S F Sanchez ◽  
A Schaefer ◽  
...  
Keyword(s):  
Gas Phase ◽  
Physical Interpretation ◽  
Stellar Mass ◽  
Instrumental Effects ◽  
Physical Origin ◽  
The Galaxy ◽  
Mass Size ◽  
Nearby Galaxies

ABSTRACT Gas-phase abundances and abundance gradients provide much information on past stellar generations, and are powerful probes of how galaxies evolve. Gas abundance gradients in galaxies have been studied as functions of galaxies’ mass and size individually, but have largely not been considered across the galaxy mass–size plane. Thus, we investigate gas-phase abundance gradients across this plane, using a sample of over 1000 galaxies selected from the MApping Nearby Galaxies at APO (MaNGA) spectroscopic survey. We find that gradients vary systematically such that above 1010 M⊙, smaller galaxies display flatter gradients than larger galaxies at a given stellar mass. This mass–size behaviour cannot be explained by instrumental effects, nor is it simply a reflection of known trends between gradients and morphology. We explore multiple possibilities for a physical origin for this pattern, though further work is needed to establish a firm physical interpretation.

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