Pinastry Science Duty Logs

Moderator: Kermie Mistwallow

User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220731.2313

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080100.01
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.09 percent
Oxygen = 20.12 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.27 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.01 magnitude in brightness.


Today's project : The nature of the radio source detected towards the exoplanet system 1RXS1609.1−210524.

Several studies have been carried out to detect radio emissions from known exoplanets. Some of these studies have resulted in tentative detections of radio sources near the position of known exoplanets. One such planet/brown dwarf around which a radio source was detected is 1RXS1609.1−210524 (hereafter 1RX) b. A radio source near 1RX was detected with the TIFR GMRT Sky Survey (TGSS) at 150 MHz and the NRAO VLA Sky Survey (NVSS) at 1.4 GHz. However, since these surveys’ spatial resolution was low, it was not possible to ascertain whether the radio emission originated from the system or a background source. This work presents results from the 1RX field’s targeted observations at 150, 325, and 610 MHz with Giant Meterwave Radio Telescope (GMRT). These observations have a higher angular resolution as compared to TGSS and NVSS. I detected the radio source near the position of 1RX at all frequencies with GMRT. I further used the Very Large Array Sky Survey (VLASS) data at 3 GHz to determine the flux density and position at high frequency. With the targeted GMRT observations and observations from VLASS, I show that the radio emission does not originate from the 1RX b but is from a background source about ∼13 arcsec away from the host star. Further, no radio emission was detected from the position of 1RX.


-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220801.2322

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080200.01
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's + 1 cadet Intelligence Branch
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.08 percent
Oxygen = 20.10 percent
Argon = 0.86 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.31 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.07 magnitude in brightness.


Today's project : Atmospheric Overturning Circulation on Dry, Tidally Locked Rocky Planets Is Mainly Driven by Radiative Cooling.

In this study, we examine the driving mechanism for the atmospheric overturning circulation on dry, tidally locked rocky planets without the condensation of water vapor or other species. We find that the main driving process is the radiative cooling of CO2 (or other noncondensable greenhouse gases) rather than CO2 greenhouse warming or stellar radiation. Stellar radiation is the ultimate mechanism but not the direct mechanism. Due to the combination of the uneven distribution in the stellar radiation and effective horizontal energy transports in the free troposphere, there is strong temperature inversion in the area away from the substellar region. This inversion makes CO2 have a radiative cooling effect rather than a radiative warming effect for the atmosphere, the same as that in the stratosphere of Earth's atmosphere. This cooling effect produces negative buoyancy and drives large-scale downwelling, supporting the formation of a global-scale overturning circulation. If CO2 is excluded from the atmosphere, the overturning circulation becomes very weak, regardless of the level of stellar radiation. This mechanism is completely different from that for the atmospheric overturning circulation on Earth or on moist, tidally locked rocky planets, where latent heat release and/or baroclinic instability are the dominated mechanisms. Our study improves the understanding of the atmospheric circulation on tidally locked exoplanets and also on other dry planets, such as Venus and Mars in the solar system.


-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220802.2344

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080300.30
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.09 percent
Oxygen = 20.10 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.29 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.01 magnitude in brightness.


Today's project : The effects of nonlinearities on tidal flows in the convective envelopes of rotating stars and planets in exoplanetary systems

In close exoplanetary systems, tidal interactions drive orbital and spin evolution of planets and stars over long timescales. Tidally-forced inertial waves (restored by the Coriolis acceleration) in the convective envelopes of low-mass stars and giant gaseous planets contribute greatly to the tidal dissipation when they are excited and subsequently damped (e.g. through viscous friction), especially early in the life of a system. These waves are known to be subject to nonlinear effects, including triggering differential rotation in the form of zonal flows. In this study, we use a realistic tidal body forcing to excite inertial waves through the residual action of the equilibrium tide in the momentum equation for the waves. By performing 3D nonlinear hydrodynamical simulations in adiabatic and incompressible convective shells, we investigate how the addition of nonlinear terms affects the tidal flow properties, and the energy and angular momentum redistribution. In particular, we identify and justify the removal of terms responsible for unphysical angular momentum evolution observed in a previous numerical study. Within our new set-up, we observe the establishment of strong cylindrically-sheared zonal flows, which modify the tidal dissipation rates from prior linear theoretical predictions. We demonstrate that the effects of this differential rotation on the waves neatly explains the discrepancies between linear and nonlinear dissipation rates in many of our simulations. We also highlight the major role of both corotation resonances and parametric instabilities of inertial waves, which are observed for sufficiently high tidal forcing amplitudes or low viscosities, in affecting the tidal flow response.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220803.2307

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080400.05
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.07 percent
Oxygen = 20.11 percent
Argon = 0.86 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.27 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.02 magnitude in brightness.


Today's project : Estimating the potential of ionizing radiation-induced radiolysis for microbial metabolism in terrestrial planets with rarefied atmospheres

Ionizing radiation is known to have a destructive impact on biology by causing damage to the DNA, cells, and production of Reactive Oxygen Species (ROS) among other things. While direct exposure to high radiation dose is indeed not favorable for biological activity, ionizing radiation can, and in some cases is known to produce a number of biologically useful products. One such mechanism is the production of biologically useful products via charged particle-induced radiolysis. Energetic charged particles interact with surfaces of planetary objects such as Mars, Europa and Enceladus without much shielding from their rarefied atmospheres. Depending on the energy of said particles, they can penetrate several meters deep below the surface and initiate a number of chemical reactions along the way. Some of the byproducts are impossible to produce with lower-energy radiation (such as sunlight), opening up new avenues for life to utilize them. For each of these cases, we calculate the energy deposition rate as a function of depth, and estimate the energy availability for potential metabolic activity. We discuss various mechanisms through which life could support itself utilizing the byproducts of these ionizing radiation-induced reactions, such as chemoautotrophs using solvated electrons, extracellular electron transfer, and indirect electrophy to facilitate processes like carbon fixation, nitrogen fixation and sulfate reduction, and possibly for ATP production.



-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220804.2322

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080500.20
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.06 percent
Oxygen = 20.12 percent
Argon = 0.87 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.24 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.03 magnitude in brightness.


Today's project : Star-Planet Interaction: Wave Structures and Wing-Wing Interaction.

Electromagnetic Star-Planet Interaction (SPI) describes the phenomenon, when a planet couples to its host star via electromagnetic forces. Alfvén waves can establish such a coupling by forming Alfvén wings. SPI allows phenomena that we do not know from the Solar System. Wing-wing interaction is such an example, where the Alfvén wings of two planets merge and interact non-linearly. In this paper we focus on the effects that SPI has on other planets and the stellar wind. First, we analyse the different wave structures connected to SPI. The second part then investigates wing-wing interaction. Our study applies a magnetohydrodynamic model to describe a stellar system with multiple possible planets. As an example, we chose TRAPPIST-1 and its two innermost planets. We extended the PLUTO code to simulate collisions between atmospheric neutral particles and plasma ions. Neutral gas clouds imitate the planets and move through the simulation domain. That allows the simulation of fully time-dependent stellar systems. We analysed the wave structures, which result from the interaction between stellar wind and TRAPPIST-1 b. The inward going wave structure is an Alfvén wing. The outward going part of the interaction consists of an Alfvén wing, slow mode waves, the planetary wake and a slow shock. We quantified the strength of the respective wave perturbations at the outer planets to be on the order of 10\% to 40\% of the local background values of thermal, magnetic and dynamic pressure. Wing-wing interaction occurs due to the relative position of two planets during their conjunction and shows three phases. First there is an initial, non-linear intensification of the Poynting flux by 20%, an intermediate phase with reduced Poynting flux and a third phase when the Alfvén wing of planet c goes through planet b's wave structures with another intensification of the Poynting flux.



-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220807.0022

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080701.20
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.05 percent
Oxygen = 20.10 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.27 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. Three active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.01 magnitude in brightness.


Today's project : H2S and SO2 detectability in Hot Jupiters: Sulfur species as indicator of metallicity and C/O ratio.

The high cosmic abundance and the intermediate volatility and chemical properties of sulfur allow the use of S-bearing species as a tracer of the chemical processes in the atmospheres of hot Jupiters. Nevertheless, despite its properties and relevance as a tracer of the giant planets' formation history, little attention has been paid to this species in the context of hot Jupiter's atmospheres. In this paper, we provide an overview of the abundances of sulfur-bearing species in hot Jupiter atmospheres under different conditions and explore their observability. We use the photochemical kinetics code VULCAN to model hot Jupiter atmospheric disequilibrium chemistry. Transmission spectra for these atmospheres are created using the modelling framework ARCiS. We vary model parameters such as the diffusion coefficient Kzz, and we study the importance of photochemistry on the resulting mixing ratios. Furthermore, we vary the chemical composition of the atmosphere by increasing the metallicity from solar to ~10 times solar. We also explore different C/O ratios. We find that H2S and SO2 are the best candidates for detection between 1 and 10 micron, using a spectral resolution that is representative of the instruments on board the James Webb Space Telescope (JWST). H2S is easiest to detect at an equilibrium temperature of ~1500 K and C/O ratios between 0.7 and 0.9, with the ideal value increasing slightly for increasing metallicity. SO2 is most likely to be detected at an equilibrium temperature of ~1000 K at low C/O ratios and high metallicities. Nevertheless, among these two molecules, we expect SO2 detection to be more common, as is the most favoured scenario from formation models. We conclude that H2S and SO2 will most likely be detected in the coming years with the JWST and that the detection of these species will provide information on atmospheric processes and planet formation scenarios.



-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220807.2331

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080800.01
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's + Major Lei Hanfoi
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.06 percent
Oxygen = 20.11 percent
Argon = 0.87 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.23 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. Three active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.04 magnitude in brightness.


Today's project : Edge-of-the-Multis: Evidence for a Transition in the Outer Architectures of Compact Multiplanet Systems.

Although the architectures of compact multiple-planet systems are well characterized, there has been little examination of their "outer edges," or the locations of their outermost planets. Here we present evidence that the observed high-multiplicity Kepler systems truncate at smaller orbital periods than can be explained by geometric and detection biases alone. To show this, we considered the existence of hypothetical planets orbiting beyond the observed transiting planets with properties dictated by the "peas-in-a-pod" patterns of intrasystem radius and period ratio uniformity. We evaluated the detectability of these hypothetical planets using (1) a novel approach for estimating the mutual inclination dispersion of multitransiting systems based on transit chord length ratios, and (2) a model of transit probability and detection efficiency that accounts for the impacts of planet multiplicity on completeness. Under the assumption that the "peas-in-a-pod" patterns continue to larger orbital separations than observed, we find that ≳35% of Kepler compact multis should possess additional detected planets beyond the known planets, constituting a ∼7σ discrepancy with the lack of such detections. These results indicate that the outer (∼100–300 days) regions of compact multis experience a truncation (i.e., an "edge-of-the-multis") or a significant breakdown of the "peas-in-a-pod" patterns, in the form of systematically smaller radii or larger period ratios. We outline future observations that can distinguish these possibilities, and we discuss implications for planet formation theories.



-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220809.0008

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22080901.00
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.08 percent
Oxygen = 20.09 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.22 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. Two active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.01 magnitude in brightness.


Today's project : Datumless Topography: A Universally Consistent Way to Quantify Relief.

Despite having long been the standard for quantifying relief on Earth and beyond, elevation has its limitations. The zero-elevation datum is defined by arbitrary and inconsistent conventions, especially on planets without a sea level, hence the lack of a universally standardized way to quantify relief. Furthermore, when quantifying relief on such planets, the elevation of a point is rather meaningless on its own, deriving most of its value when compared to the elevation of other points. In light of these considerations, this paper introduces a universally consistent framework for quantifying relief that does not require a datum altogether, and is instead based on physically meaningful concepts. Designed to be mathematically elegant and free of arbitrary parameters, the so-called datumless measures are divided into the datumless point measures and the datumless surface measures. As opposed to elevation, which describes the vertical position of a point relative to a datum, the datumless point measures directly describe the vertical position of a point relative to local terrain, making them useful for comparing the relief of features such as mountains across different planets. In the meantime, the datumless surface measures quantify various aspects of relief within a region, as opposed to that of a single point. This is done through datumless formulations of surface area and surface mean value, which can be directly applied to the fractal-like planetary surface without projecting it onto a reference ellipsoid. Altogether, this paper lays the groundwork for a datumless framework that enables future topographic tasks to transcend the limitations of elevation.



-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220811.0422

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081101.30
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.07 percent
Oxygen = 20.11 percent
Argon = 0.87 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.24 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. Two active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.08 magnitude in brightness.


Today's project : The space coronagraph optical bench (SCoOB): 2. wavefront sensing and control in a vacuum-compatible coronagraph testbed for spaceborne high-contrast imaging technology
The 2020 Decadal Survey on Astronomy and Astrophysics endorsed space-based high contrast imaging for the detection and characterization of habitable exoplanets as a key priority for the upcoming decade. To advance the maturity of starlight suppression techniques in a space-like environment, we are developing the Space Coronagraph Optical Bench (SCoOB) at the University of Arizona, a new thermal vacuum (TVAC) testbed based on the Coronagraphic Debris Exoplanet Exploring Payload (CDEEP), a SmallSat mission concept for high contrast imaging of circumstellar disks in scattered light. When completed, the testbed will combine a vector vortex coronagraph (VVC) with a Kilo-C microelectromechanical systems (MEMS) deformable mirror from Boston Micromachines Corp (BMC) and a self-coherent camera (SCC) with a goal of raw contrast surpassing 10−8 at visible wavelengths. In this proceedings, we report on our wavefront sensing and control efforts on this testbed in air, including the as-built performance of the optical system and the implementation of algorithms for focal-plane wavefront control and digging dark holes (regions of high contrast in the focal plane) using electric field conjugation (EFC) and related algorithms.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220813.2325

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081400.25
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.09 percent
Oxygen = 20.09 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.26 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.01 magnitude in brightness.


Today's project : Orbital Characterization of Superbolides Observed from Space: Dynamical Association with Near-Earth Objects, Meteoroid Streams, and Identification of Hyperbolic Meteoroids.

There is an unceasing incoming flux of extraterrestrial materials reaching the Earth atmosphere. Some of these objects produce luminous columns when they ablate during the hypersonic encounter with air molecules. A few fireballs occur each year bright enough to be detected from space. The source of these events is still a matter of debate, but it is generally accepted that they are of sporadic origin. We studied the NASA-JPL Center for NEOs Studies (CNEOS) fireball database to infer the dynamic origin of large bolides produced by meter-sized projectiles that impacted our planet. These likely meteorite-dropping events were recorded by the US Government satellite sensors. We estimated the false-positive rate and analyzed the time evolution of multiple orbit dissimilarity criteria concerning potential associations with near-Earth objects and meteoroid streams. We found that at least 16% of the large bolides could be associated with meteoroid streams, about 4% are likely associated with near-Earth asteroids, and 4% may be linked to near-Earth comets. This implies that a significant fraction of meter-sized impactors producing large bolides may have an asteroidal or cometary origin. In addition, we found at least three bolides having hyperbolic orbits with high tensile strength values. Meter-sized meteoroids of interstellar origin could be more common than previously thought, representing about 1% of the flux of large bolides. The inferred bulk physical properties suggest that the interstellar medium could bias these projectiles toward high strength rocks with the ability to survive prolonged exposure to the harsh interstellar space conditions.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220814.2324

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081500.20
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.07 percent
Oxygen = 20.07 percent
Argon = 0.86 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.29 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.05 magnitude in brightness.

Today's project : Project Lyra: A mission to 1I/’Oumuamua without Solar Oberth Manoeuvre.

To settle the question of the nature of the interstellar object 1I/’Oumuamua requires in-situ observations via a spacecraft, as the object is already out of range of existing telescopes. Most previous proposals for reaching 1I/’Oumuamua using near-term technologies are based on the Solar Oberth Manoeuvre (SOM), as trajectories without the SOM are generally significantly inferior in terms of lower mission duration and higher total velocity requirement. While the SOM allows huge velocity gains, it is also technically challenging and thereby increases programmatic and mission-related risks. In this paper, we identify an alternative route to the interstellar object 1I/’Oumuamua, based on a launch in 2028, which does not require a SOM but has a similar performance as missions with a SOM. It instead employs a Jupiter Oberth Manoeuvre (JOM) with a total time of flight of around 26 years or so. The efficacy of this trajectory is a result of it significantly reducing the V to Jupiter by exploiting the VEEGA sequence. The total V of the trajectory is 15.8 and the corresponding payload mass is 115 for a SLS Block 1B or 241 for a Block 2. A further advantage of the JOM is that the arrival speed relative to 1I/’Oumuamua is approximately 18 , much lower than the equivalent for the SOM of around 30 .

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220815.2301

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081600.01
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.05 percent
Oxygen = 20.04 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.31 percent (elevated levels, still within range but something to keep an eye on).
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with low active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Brightned by 0.05 magnitude in brightness.

Today's project : Neural-Rendezvous: Learning-based Robust Guidance and Control to Encounter Interstellar Objects.

Interstellar objects (ISOs), astronomical objects not gravitationally bound to the Sun, are likely representatives of primitive materials invaluable in understanding exoplanetary star systems. Due to their poorly constrained orbits with generally high inclinations and relative velocities, however, exploring ISOs with conventional human-in-the-loop approaches is significantly challenging. This paper presents Neural-Rendezvous -- a deep learning-based guidance and control framework for encountering any fast-moving objects, including ISOs, robustly, accurately, and autonomously in real-time. It uses pointwise minimum norm tracking control on top of a guidance policy modeled by a spectrally-normalized deep neural network, where its hyperparameters are tuned with a newly introduced loss function directly penalizing the state trajectory tracking error. We rigorously show that, even in the challenging case of ISO exploration, Neural-Rendezvous provides 1) a high probability exponential bound on the expected spacecraft delivery error; and 2) a finite optimality gap with respect to the solution of model predictive control, both of which are indispensable especially for such a critical space mission. In numerical simulations, Neural-Rendezvous is demonstrated to achieve a terminal-time delivery error of less than 0.2 km for 99% of the ISO candidates with realistic state uncertainty, whilst retaining computational efficiency sufficient for real-time implementation.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220816.2324

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081700.20
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.08 percent
Oxygen = 20.08 percent
Argon = 0.87 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.29 percent (lower level again, wonder what triggered those high values yesterday).
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with average active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Dimmed by 0.03 magnitude in brightness.



Today's project : A mini-chemical scheme with net reactions for 3D general circulation models.

Context. Growing evidence has indicated that the global composition distribution plays an indisputable role in interpreting observational data. Three-dimensional general circulation models (GCMs) with a reliable treatment of chemistry and clouds are particularly crucial in preparing for upcoming observations. In attempts to achieve 3D chemistry-climate modeling, the challenge mainly lies in the expensive computing power required for treating a large number of chemical species and reactions.

Aims. Motivated by the need for a robust and computationally efficient chemical scheme, we devise a mini-chemical network with a minimal number of species and reactions for H2-dominated atmospheres.

Methods. We apply a novel technique to simplify the chemical network from a full kinetics model, VULCAN, by replacing a large number of intermediate reactions with net reactions. The number of chemical species is cut down from 67 to 12, with the major species of thermal and observational importance retained, including H2O, CH4, CO, CO2, C2H2, NH3, and HCN. The size of the total reactions is also greatly reduced, from ~800 to 20. We validated the mini-chemical scheme by verifying the temporal evolution and benchmarking the predicted compositions in four exoplanet atmospheres (GJ 1214b, GJ 436b, HD 189733b, and HD 209458b) against the full kinetics of VULCAN.

Results. The mini-network reproduces the chemical timescales and composition distributions of the full kinetics well within an order of magnitude for the major species in the pressure range of 1 bar–0.1 mbar across various metallicities and carbon-to-oxygen (C/O) ratios.

Conclusions. We have developed and validated a mini-chemical scheme using net reactions to significantly simplify a large chemical network. The small scale of the mini-chemical scheme permits simple use and fast computation, which is optimal for implementation in a 3D GCM or a retrieval framework. We focus on the thermochemical kinetics of net reactions in this paper and address photochemistry in a follow-up paper.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220818.0010

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081801.00
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.06 percent
Oxygen = 20.09 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.27 percent (keeps dropping but still a bit higher than normal).
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with average active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Dimmed by 0.015 magnitude in brightness.



Today's project : Planetary occurrence rates around early-M dwarfs.

Aims. We present the complete Bayesian statistical analysis of the HArps-n red Dwarf Exoplanet Survey (HADES), which monitored the radial velocities of a large sample of M dwarfs with HARPS-N at TNG over the last 6 yr.

Methods. The targets were selected in a narrow range of spectral types from M0 to M3, 0.3 M⊙ < M★ < 0.71 M⊙, in order to study the planetary population around a well-defined class of host stars. We take advantage of Bayesian statistics to derive an accurate estimate of the detectability function of the survey. Our analysis also includes the application of a Gaussian Process approach to take into account stellar-activity-induced radial velocity variations and improve the detection limits around the most-observed and most-active targets. The Markov chain Monte Carlo and Gaussian process technique we apply in this analysis has proven very effective in the study of M-dwarf planetary systems, helping the detection of most of the HADES planets.

Results. From the detectability function we can calculate the occurrence rate of small-mass planets around early-M dwarfs, either taking into account only the 11 already published HADES planets or adding the five new planetary candidates discovered in this analysis, and compare them with the previous estimates of planet occurrence around M-dwarf or solar-type stars: considering only the confirmed planets, we find the highest frequency for low-mass planets (1 M⊕ < mp sin i < 10 M⊕) with periods 10 d < P < 100 d, , while for short-period planets (1 d < P < 10 d) we find a frequency of , significantly lower than for later-M dwarfs; if instead we also take into account the new candidates, we observe the same general behaviours, but with consistently higher frequencies of low-mass planets. We also present new estimates of the occurrence rates of long-period giant planets and temperate planets inside the habitable zone of early-M dwarfs: in particular we find that the frequency of habitable planets could be as low as η⊕ < 0.23. These results, and their comparison with other surveys focused on different stellar types, confirm the central role that stellar mass plays in the formation and evolution of planetary systems.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
User avatar
Ferre Flamand
Sciences - Lieutenant
Sciences - Lieutenant
Posts: 358
Joined: 211111.0543
Duty Post: Vice Chief Science Officer
Ship/Station Posted: SS Tranquility
Grid: Second Life
Location: Belgium
Has thanked: 185 times
Been thanked: 54 times
Contact:

220818.2328

Tranquility Station/Ops + Tranquility Science Lab - Stardate 22081900.05
Reporting Officer: Lt Ferre Flamand
Other Officers on Duty: 4 NPC's
Duty Log
Daily Scientific and Observation Report


Surface environmental conditions

Nitrogen = 77.07 percent
Oxygen = 20.11 percent
Argon = 0.88 percent
Neon, Helium, Krypton = 0.0008 percent
Carbon dioxide = 0.26 percent
Water vapor = 0 - 4 percent

Fauna and Flora = All specific data found in local database.
Daystar condition = Thermal radiation within acceptable margins. One active sunspot-grouping detected with average active flares. No communication interference can be expected. Warming-up sequence at normal rate within range.

Betelgeuse (Alpha Orionis) its variable magnitude intervals within range. Dimmed by 0.011 magnitude in brightness.



Today's project : Inferred Properties of Planets in Mean-Motion Resonances are Biased by Measurement Noise.

Planetary systems with mean-motion resonances (MMRs) hold special value in terms of their dynamical complexity and their capacity to constrain planet formation and migration histories. The key towards making these connections, however, is to have a reliable characterization of the resonant dynamics, especially the so-called "libration amplitude", which qualitatively measures how deep the system is into the resonance. In this work, we identify an important complication with the interpretation of libration amplitude estimates from observational data of resonant systems. Specifically, we show that measurement noise causes inferences of the libration amplitude to be systematically biased to larger values, with noisier data yielding a larger bias. We demonstrated this through multiple approaches, including using dynamical fits of synthetic radial velocity data to explore how the the libration amplitude distribution inferred from the posterior parameter distribution varies with the degree of measurement noise. We find that even modest levels of noise still result in a slight bias. The origin of the bias stems from the topology of the resonant phase space and the fact that the available phase space volume increases non-uniformly with increasing libration amplitude. We highlight strategies for mitigating the bias through the usage of particular priors. Our results imply that many known resonant systems are likely deeper in resonance than previously appreciated.

-- end log --

:communicator: Lt Ferre Flamand
Vice Chief Science Officer
SS Tranquility
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