相关论文: The meteoroid hazard for space navigation
The population of artificial satellites and space debris orbiting the Earth imposes non-negligible constraints on both space operations and ground-based optical and radio astronomy. The ongoing deployment of several satellite…
Earth is constantly being bombarded with material from space. Most of the natural material end up being dust grains that litter the surface of Earth, but larger bodies are known to impact every few decades. The most recent large impact was…
Understanding extreme space weather events is of paramount importance in efforts to protect technological systems in space and on the ground. Particularly in the thermosphere, the subsequent extreme magnetic storms can pose serious threats…
Radiation hazard on board of a relativistic rocket can be of internal and external origin. Because of its highest specific energy density, antimatter is considered to be the preferred rocket fuel for accelerating a multi-ton rocket up to…
Large satellite constellations in low-Earth orbit seek to be the infrastructure for global broadband Internet and other telecommunication needs. We briefly review the impacts of satellite constellations on astronomy and show that the…
Private space companies are increasingly commercializing near-earth space. Some estimates show that more than 100,000 satellites may orbit the Earth by 2030. This increase in the number of satellites has many consequences for science,…
Every year, more and more objects are sent to space. While staying in orbit at high altitudes, objects at low altitudes reenter the atmosphere, mostly disintegrating and adding material to the upper atmosphere. The increasing number of…
Satellites around large asteroids are preferentially found among those with the most rapid rotation and elongated shape. The taxonomic statistics are similarly skewed; in total, 13 asteroids larger than 100 km are known to have satellites,…
In this paper, a meteoric plasma is analyzed from a physical viewpoint, with particular emphasis on its interaction with radio waves. The attention is drawn to some macroscopic characteristics of a meteoric plasma and it is shown that the…
The equations governing motion of the satellite under the effect of oblateness of Earth and atmospheric drag have been simulated, for a fixed initial position and three different initial velocities, till satellite collapses on Earth.…
Astrophysical fluids are turbulent, magnetized and frequently partially ionized. As an example of astrophysical turbulence, the interstellar turbulence extends over a remarkably large range of spatial scales and participates in key…
We investigate how the survival of dark matter satellites inside virialized halos depends on tidal stripping and dynamical friction. We use an analytic approach and then compare the results with N-Body simulations. Both the satellites and…
Planetary satellites are an integral part of the heirarchy of planetary systems. Here we make two predictions concerning their formation. First, primordial satellites, which have an array of distinguishing characteristics, form only around…
Every year, a few metre-sized meteoroids impact the atmosphere of the Earth. Most (if not all) of them are undetectable before the impact. Therefore, predicting where and how they will fall seems to be an impossible task. In this letter we…
The number of space objects will grow several times in a few years due to the planned launches of constellations of thousands microsatellites. It leads to a significant increase in the threat of satellite collisions. Spacecraft must…
Like all natural hazards, space weather exhibits occasional extreme events over timescales of decades to centuries. Historical events provoked much interest but had little economic impact. However, the widespread adoption of advanced…
500,000 to 1 million satellites are expected in the next decades, primarily to build internet constellations called megaconstellations. These megaconstellations are disposable and will constantly re-enter and be replaced, hence creating a…
This paper calculates the spatial distribution of the plasma responsible for radar head echoes by applying the kinetic theory developed in the companion paper (Dimant and Oppenheim, arXiv:1608.08524). This results in a set of analytic…
Shock waves and the associated phenomena generated by strongly ablating meteoroids with sizes greater than a few millimeters in the lower transitional flow regime of the Earth's atmosphere are the least explored aspect of meteor science. In…
Large satellite constellations are one of the main reasons for an increasing amount of mass being brought into low Earth orbit in recent years. After end of life, the satellites, as well as rocket stages, reenter Earth's atmosphere. This…