相关论文: Interstellar Escape from Proxima b is Barely Possi…
We report Spitzer Space Telescope observations during predicted transits of the exoplanet Proxima Centauri b. As the nearest terrestrial habitable-zone planet we will ever discover, any potential transit of Proxima b would place strong…
Atmospheric escape is an important process that influences the evolution of planetary atmospheres. A variety of physical mechanisms can contribute to escape from an atmosphere, including thermal escape, ion escape, photochemical escape, and…
The preponderance of white dwarfs in the Milky Way were formed from the remnants of stars of the same or somewhat higher mass as the Sun, i.e., from G-stars. We know that life can exist around G-stars. Any technologically advanced…
From the point of view of radiation safety, interstellar space is not an empty void. Interstellar gas and cosmic rays, which consist of hydrogen and helium nucleons, present a severe radiation hazard to crew and electronics aboard a…
We investigate analytically whether in a close encounter with a star, a Dark Matter particle can be accelerated above the escape speed of a Globular Cluster and be ejected. We find that this mechanism is not sufficient to eject a massive,…
Extrasolar planets and belts of debris orbiting post-main-sequence single stars may become unbound as the evolving star loses mass. In multiple star systems, the presence or co-evolution of the additional stars can significantly complicate…
A long-lived civilization will inevitably have to migrate towards a nearby star as its home star runs out of nuclear fuel. One way to achieve such a migration is by transforming its star into a stellar engine, and to control its motion in…
We have carried out a series of calculations involving bacteria and viruses embedded in dust grains, which are ejected from our solar system by radiation pressure, and travel through space to other star systems. Under many conditions, this…
It is often suggested that extraterrestial life sufficiently advanced to be capable of interstellar travel or communication must be rare, since otherwise we would have seen evidence of it by now. This in turn is sometimes taken as indirect…
In the future interstellar exploration at near-relativistic speeds will be possible using beamed energy laser propulsion. With this, spacecraft as small as gm mass picospacecraft become candidates for the exploration of deep space, with a…
The fate of metals after they are released in starburst episodes is still unclear. What phases of the interstellar medium are involved, in which timescales? Evidence has grown over the past few years that the neutral phase of blue compact…
We analyze the evolution of the potentially habitable planet Proxima Centauri b to identify environmental factors that affect its long-term habitability. We consider physical processes acting on size scales ranging from the galactic to the…
Advanced civilizations capable of interstellar travel, if they exist, are likely to have advanced propulsion methods. Spaceships moving at high speeds would leave a particular signature which could be detected from Earth. We propose a…
A vast wealth of literature exists on the topic of rocket trajectory optimisation, particularly in the area of interplanetary trajectories due to its relevance today. Studies on optimising interstellar and intergalactic trajectories are…
The habitable zone (HZ) is commonly defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist on a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere…
The galactic environment has been suspected to influence planetary habitability in many ways. Very metal-poor regions of the Galaxy, or those largely devoid of atoms more massive than H and He, are thought to be unable to form habitable…
Water has been identified as a critical resource both to sustain human-life but also for use in propulsion, attitude-control, power, thermal and radiation pro-tection systems. Water may be obtained off-world through In-Situ Resource…
The fact that we apparently live in an accelerating universe places limitations on where humans might visit. If the current energy density of the universe is dominated by a cosmological constant, a rocket could reach a galaxy observed today…
The closest potentially habitable worlds outside our Solar system orbit a different kind of star than our Sun: smaller red dwarf stars. Such stars can flare frequently, bombarding their planets with biologically damaging high-energy UV…
You have a rocket in a high circular orbit around a massive central body (a planet, or the Sun) and wish to escape with the fastest possible speed at infinity for a given amount of fuel.