Related papers: UFOs: Just Hot Air or Something Meteor?
Close planetary flybys are frequently employed as a technique to place spacecraft on extreme solar system trajectories that would otherwise require much larger booster vehicles or may not even be feasible when relying solely on chemical…
A collection is made of presently unexplained phenomena within our Solar system and in the universe. These phenomena are (i) the Pioneer anomaly, (ii) the flyby anomaly, (iii) the increase of the Astronomical Unit, (iv) the quadrupole and…
Recent observational and theoretical results on blazars are presented and discussed. We are beginning to understand the rich phenomenology of blazars, and we are finding trends which will hopefully lead us to unveil the physics of these…
We use a simple yet Earth-like atmospheric model to propose a new framework for understanding the mathematics of blocking events. Analysing error growth rates along a very long model trajectory, we show that blockings are associated with…
High altitude meteors become luminous at altitudes above $\sim$130 km, where the standard ablation theory of meteor light production is not applicable. The physical mechanism responsible for their glow has not been known. We present a model…
Context. Comet 46P/Wirtanen is a near-Earth object (NEO) for which no associated meteor shower has ever been reported. Aims. This study is aimed at improving our understanding of why there has been no observed shower activity for this NEO…
Ultra-hot Jupiters, an extreme class of planets not found in our solar system, provide a unique window into atmospheric processes. The extreme temperature contrasts between their day- and night-sides pose a fundamental climate puzzle: how…
The discovery of exoplanets has both focused and expanded the search for extraterrestrial intelligence. The consideration of Earth as an exoplanet, the knowledge of the orbital parameters of individual exoplanets, and our new understanding…
Video observations of Jupiter obtained by amateur astronomers over the past eight years have shown five flashes of light of 1-2 s. The first three of these events occurred on 3 June 2010, 20 August 2010, and 10 September 2012. Previous…
Pulsar wind nebulae are now well established as important probes both of neutron stars' relativistic winds and of the surrounding interstellar medium. Amongst this diverse group of objects, pulsar bow shocks have long been regarded as an…
Context. Ultra fast outflows (UFOs) from active galactic nuclei (AGN) are expected to lead to the formation of sub-relativistic strong shocks expanding in a dense circumnuclear medium, and thus have the potential for being efficient…
Meteor physics can provide new clues about the size, structure, and density of cometary disintegration products, establishing a bridge between different research fields. From meteor magnitude data we have estimated the mass distribution of…
We present a comparison of the parameters of accretion disc outflows and the jet of the broad-line radio galaxy 3C 111 on sub-pc scales. We make use of published X-ray observations of ultra-fast outflows (UFOs) and new 43GHz VLBA images to…
There have been several reports of exotic nuclear fragments, with highly unusual charge to mass ratio, in cosmic ray experiments. Although there exist experimental uncertainties which make them, at best, only candidate "exotic" events, it…
We perform a thorough investigation of (ultra)relativistic freeze-out (UFO) during reheating. While the standard WIMP (non-relativistic freeze-out) and FIMP (freeze-in) paradigms have been explored in detail during the reheating epoch, UFO…
Recently new data from the Cosmo-LEP project appeared, this time from DELPHI detector. They essentially confirm the findings reported some time ago by ALEPH, namely the appearence of bundles of muons with unexpectedly high multiplicities,…
Firm evidence for a radio emission counterpart of cosmic ray air showers is presented. By the use of an antenna array set up in coincidence with ground particle detectors, we find a collection of events for which both time and arrival…
Extreme Scattering Events are radio-wave lensing events caused by AU-sized concentrations of ionised gas. Although they were discovered more than a decade ago we still have no clear picture of the physical nature of the lenses. To…
The encounter of the meteoric material from 73P/Schmassmann--Wachmann~3 produced during the comet's 1995 outburst in May 2022 provides a rare and valuable opportunity to understand a fragmenting comet. Here we explore various ejection…
A conjecture on imminent earthquake prediction is presented. Drastic geological deformations of crustal rock strata taking place immediately (hours/days) before an earthquake may cause fast air or gas emission/absorption vertically in…