Related papers: Free-floating planets: a viable option for pansper…
In the last years several exoplanets have been discovered that orbit one component of a compact binary system (separation < 50 astronomical units), the probably best-known case is gamma-Cephei. So far, all attempts to explain the in-situ…
We present a series of calculations aimed at examining how an inner system of planetesimals/protoplanets, undergoing terrestrial planet formation, evolves under the influence of a giant planet undergoing inward type II migration through the…
The large number of exoplanets found to orbit their host stars in very close orbits have significantly advanced our understanding of the planetary formation process. It is now widely accepted that such short-period planets cannot have…
As of today over 40 planetary systems have been discovered in binary star systems. In all cases the configuration appears to be circumstellar, where the planets orbit around one of the stars, the secondary acting as a perturber. The…
Gas giant planets have been detected on eccentric orbits several hundreds of astronomical units in size around other stars. It has been proposed that even the Sun hosts a wide-orbit planet of 5-10 Earth masses, often called Planet Nine,…
The data recently accumulated by the Kepler mission have demonstrated that small planets are quite common and that a significant fraction of all stars may have an Earth-like planet within their Habitable Zone. These results are combined…
Among the methods proposed to detect extrasolar planets, microlensing is the only technique that can detect free-floating planets. Free-floating planets are detected through the channel of short-duration isolated lensing events. However, if…
Most stars form in star clusters and stellar associated. To understand the roles of star cluster environments in shaping the dynamical evolution of planetary systems, we carry out direct $N$-body simulations of four planetary systems models…
Many observed giant planets lie on eccentric orbits. Such orbits could be the result of strong scatterings with other giant planets. The same dynamical instability that produces these scatterings may also cause habitable planets in interior…
Most stars form in a clustered environment. Both single and binary stars will sometimes encounter planetary systems in such crowded environments. Encounter rates for binaries may be larger than for single stars, even for binary fractions as…
The discovery of 1I/`Oumuamua confirmed that planetesimals must exist in great numbers in interstellar space. Originally generated during planet formation, they are scattered from their original systems and subsequently drift through…
A modified version of panspermia theory, named Nebula-Relay hypothesis or local panspermia, is introduced to explain the origin of life on Earth. Primitive life, acting as the seeds of life on Earth, originated at pre-solar epoch through…
A scenario is presented for the formation of first life in the universe based on hydro-gravitational-dynamics (HGD) cosmology. From HGD, the dark matter of galaxies is H-He gas dominated planets (primordial-fog-particle PFPs) in million…
The Fermi paradox is the discrepancy between the strong likelihood of alien intelligent life emerging (under a wide variety of assumptions) and the absence of any visible evidence for such emergence. We use this intriguing unlikeness to…
Recent observations from NASA's Kepler mission detected the first planets in circumbinary orbits. The question we try to answer is where these planets formed in the circumbinary disk and how far inside they migrated to reach their present…
In most extrasolar planetary systems, the present orbits of known giant planets admit the existence of stable terrestrial planets. Those same giant planets, however, have typically eccentric orbits that hint at violent early dynamics less…
Microlensing observations suggest that the mass distribution of free-floating planets (FFPs) follows a declining power-law with increasing mass. The origin of such distribution is unclear. Using a population synthesis framework, we…
Our understanding of the processes that are relevant to the formation and maintenance of habitable planetary systems is advancing at a rapid pace, both from observation and theory. The present review focuses on recent research that bears on…
The study of the origin of life on Earth has been broadened due to panspermia models that suggest that early life may have been transferred between planets. Mars likely once had conditions that could support life, and it is interesting…
Free-floating planets (FFPs) can result from dynamical scattering processes happening in the first few million years of a planetary system's life. Several models predict the possibility, for these isolated planetary-mass objects, to retain…