Related papers: Free-floating planets: a viable option for pansper…
At this point in time, there is very little empirical evidence on the likelihood of a space-faring species originating in the biosphere of a habitable world. However, there is a tension between the expectation that such a probability is…
The dominant mechanism for generating free-floating planets has so far remained elusive. One suggested mechanism is that planets are ejected from planetary systems due to planet-planet interactions. However, instability around a single star…
Material from the surface of a planet can be ejected into space by a large impact, and could carry primitive life forms with it. We performed n-body simulations of such ejecta to determine where in the Solar System rock from Earth and Mars…
Secular perturbations from binary stars and distant massive planets can drive cold planets onto nearly parabolic orbits with pericenter passages extremely close to their host stars. Meanwhile, short-period super-Earths are frequently…
The proposition that life can spread from one planetary system to another (interstellar panspermia) has a long history, but this hypothesis is difficult to test through observations. We develop a mathematical model that takes parameters…
The evolution of life has been a big enigma despite rapid advancements in the fields of biochemistry, astrobiology, and astrophysics in recent years. The answer to this puzzle has been as mind-boggling as the riddle relating to evolution of…
Open clusters(OCs) are usually young and suitable for studying the formation and evolution of planetary systems. Hitherto, only four planets have been found with radial velocity measurements in OCs. Meanwhile, a lot of free-floating…
In the past 15 years, astronomers have revealed that a significant fraction of the stars should harbor planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e.…
The modestly eccentric and non-coplanar orbits of the giant planets pose a challenge to solar system formation theories which generally indicate that the giant planets emerged from the protoplanetary disk in nearly perfectly circular and…
Recent imaging campaigns indicate the likely existence of massive planets (~ 1-10 MJ) on ~1000 year orbits about a few percent of stars. Such objects are not easily explained in most current planet formation models. In this Letter we use…
Based on numbers of stars, supernova rates, and metallicity, a prior study (Dayal et al. 2015) concluded that large elliptical galaxies contain up to 10,000 times more habitable planets than the Milky Way and are thus the "cradles of life".…
In star clusters, close stellar encounters can strongly impact the architecture of a planetary system or even destroy it. We present a systematic study on the effects of stellar flybys on two-planet systems. When such a system experiences…
The Panspermia hypothesis posits that either life's building blocks (molecular Panspermia) or life itself (organism-based Panspermia) may have been interplanetary transferred to facilitate the Origins of Life (OoL) on a given planet,…
With recent observations confirming exoplanets orbiting white dwarfs, there is growing interest in exploring and quantifying the habitability of temperate rocky planets around white dwarfs. In this work, the limits of the habitable zone of…
Close-in giant planets are thought to have formed in the cold outer regions of planetary systems and migrated inward, passing through the orbital parameter space occupied by the terrestrial planets in our own Solar System. We present…
A simple stochastic model for evolution, based upon the need to pass a sequence of n critical steps (Carter 1983, Watson 2008) is applied to both terrestrial and extraterrestrial origins of life. In the former case, the time at which humans…
Planet-planet scattering is the leading mechanism to explain the broad eccentricity distribution of observed giant exoplanets. Here we study the orbital stability of primordial giant planet moons in this scenario. We use N-body simulations…
An instability among the giant planets' orbits can match many aspects of the Solar System's current orbital architecture. We explore the possibility that this dynamical instability was triggered by the close passage of a star or substellar…
The transformation of organic molecules into the simplest self-replicating living system,a microorganism, is accomplished from a unique event or rare events that occurred early in the Universe. The subsequent dispersal on cosmic scales and…
The chance that a planetary system will interact with another member of its host star's nascent cluster would be greatly increased if gas giant planets form in situ on wide orbits. In this paper, we explore the outcomes of planet-planet…