Related papers: A Fast, Semi-analytical Model for the Venusian Bin…
There are a handful of spectral windows in the near-IR through which we can see down to Venus' surface on the night side of the planet. The surface of our sister planet has thus been imaged by sensors on Venus-orbiting platforms (Venus…
What constitutes a habitable planet is a frontier to be explored and requires pushing the boundaries of our terracentric viewpoint for what we deem to be a habitable environment. Despite Venus' 700 K surface temperature being too hot for…
The initial reports of the presence of phosphine in the cloud decks of Venus has led to the suggestion that volcanism was the source of phosphine, through volcanic phosphides ejected into the clouds. Here we examine the idea that mantle…
Optical emission lines have now been detected from about 20 high velocity clouds. These emission lines -- primarily H-alpha, secondarily [N II] and [S II] -- are very faint and diffuse, spread over the surfaces of the clouds. We compile…
The potential detection of ppb levels phosphine (PH3) in the clouds of Venus through millimeter-wavelength astronomical observations is extremely surprising as PH3 is an unexpected component of an oxidized environment of Venus. A thorough…
In our solar system, the densely cloud-covered atmosphere of Venus stands out as an example of how polarimetry can be used to gain information on cloud composition and particle mean radius. With current interest running high on discovering…
High-velocity clouds consist of cold gas that appears to be raining down from the halo to the disc of the Milky Way. Over the past fifty years, two competing scenarios have attributed their origin either to gas accretion from outside the…
High-Velocity Clouds (HVCs) have radial velocities that cannot be explained by the global Galactic rotation; their distances remain mostly unknown, and their true nature and origin are still a mystery. Some of them could be of galactic…
Molecular cloud observations show that clouds have non-thermal velocity dispersions that scale with the cloud size as $\sigma\propto R^{1/2}$ at constant surface density, and for varying surface density scale with both the cloud`s size and…
In the Galactic fountain scenario, supernovae and/or stellar winds propel material into the Galactic halo. As the material cools, it condenses into clouds. By using FLASH three-dimensional magnetohydrodynamic simulations, we model and study…
A model is proposed for determining the distances to falling interstellar clouds in the galactic halo by measuring the cloud velocity and column density and assuming a model for the vertical density distribution of the Galactic interstellar…
We report vertical thermal structure and wind velocities in the Venusian mesosphere retrieved from carbon monoxide (12CO J=2-1 and 13CO J=2-1) spectral line observations obtained with the Heinrich Hertz Submillimeter Telescope (HHSMT). We…
The emergence of organized multiscale patterns resulting from convection is ubiquitous, observed throughout different cloud types. The reproduction of such patterns by general circulation models remains a challenge due to the complex nature…
An unknown absorber near the cloud top level of Venus generates a broad absorption feature from the ultraviolet (UV) to visible, peaking around 360 nm, and therefore plays a critical role in the solar energy absorption. We present a…
The Venus Life Finder Missions are a series of focused astrobiology mission concepts to search for habitability, signs of life, and life itself in the Venus atmosphere. While people have speculated on life in the Venus clouds for decades,…
We demonstrate that the observationally inferred rapid onset of star formation after parental molecular clouds have assembled can be achieved by flow-driven cloud formation of atomic gas, using our previous three-dimensional numerical…
In this work we investigate the possibility of two-stream instability in the Venusian atmosphere to lead to momentum transfer to subsequent escape of Hydrogen and Oxygen ions from the ionosphere. We employ the hydrodynamic model and obtain…
Firstly identified in images from JAXA's orbiter Akatsuki, the cloud discontinuity of Venus is a planetary-scale phenomenon known to be recurrent since, at least, the 1980s. Interpreted as a new type of Kelvin wave, this disruption is…
In an atmosphere, a cloud condensation region is characterized by a strong vertical gradient in the abundance of the related condensing species. On Earth, the ensuing gradient of mean molecular weight has relatively few dynamical…
Clouds form in atmospheres of brown dwarfs and planets. The cloud particle formation processes are similar to the dust formation process studied in circumstellar shells of AGB stars and in Supernovae. Cloud formation modelling in substellar…