Galactic Panspermia

  title={Galactic Panspermia},
  author={Idan Ginsburg and Manasvi Lingam and Abraham Loeb},
  journal={The Astrophysical Journal},
We present an analytic model to estimate the total number of rocky or icy objects that could be captured by planetary systems within the Milky Way galaxy and result in panspermia should they harbor life. We estimate the capture rate of objects ejected from planetary systems over the entire phase space as well as time. Our final expression for the capture rate depends upon the velocity dispersion as well as the characteristic biological survival time and the size of the captured object. We… Expand

Figures from this paper

The Habitability of the Galactic Bulge
Analytical models of the star density in the bulge are used to provide estimates of the rate of catastrophic events and of the diffusion timescales for life over interstellar distances. Expand
On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets
This work employs the simple but yet comprehensive model of intergalactic microprojectile capture by the gravity of exoplanets which enables it to estimate the map of collisional probabilities for an available sample of ex planets in habitable zones around host stars. Expand
Quantifying the information impact of future searches for exoplanetary biosignatures
It is shown that even a single detection of biosignatures in the vicinity of the authors' stellar system, in a survey of similar size to what will be obtainable in the next 2 decades, would affect significantly their prior belief on the frequency of life in the universe. Expand
Possible Transfer of Life by Earth-Grazing Objects to Exoplanetary Systems
It is found that 107–109 objects discovered to graze the Earth’s atmosphere and shift into a Jupiter-crossing orbit could have been captured by binary star systems over the lifetime of the Solar System. Expand
Brown Dwarf Atmospheres as the Potentially Most Detectable and Abundant Sites for Life
We show that the total habitable volume in the atmospheres of cool brown dwarfs with effective temperatures of $\sim 250$-$350$ K is possibly larger by two orders of magnitude than that of Earth-likeExpand
Active Galactic Nuclei: Boon or Bane for Biota?
Active Galactic Nuclei (AGNs) emit substantial fluxes of high-energy electromagnetic radiation, and have therefore attracted some recent attention for their negative impact on galactic habitability.Expand
Prospects for Life on Temperate Planets around Brown Dwarfs
There is growing evidence that brown dwarfs may be comparable to main-sequence stars in terms of their abundance. In this paper, we explore the prospects for the existence of life on Earth-likeExpand
On the Habitable Lifetime of Terrestrial Worlds with High Radionuclide Abundances
The presence of a liquid solvent is widely regarded as an essential prerequisite for habitability. We investigate the conditions under which worlds outside the habitable zones of stars are capable ofExpand
Role of stellar physics in regulating the critical steps for life
  • M. Lingam, A. Loeb
  • Environmental Science, Physics
  • International Journal of Astrobiology
  • 2019
Abstract We use the critical step model to study the major transitions in evolution on Earth. We find that a total of five steps represents the most plausible estimate, in agreement with previousExpand
Exploring Biogenic Dispersion Inside Star Clusters with System Dynamics Modeling
The discovery of a growing number of exoplanets and even extrasolar systems supports the scientific consensus that it is possible to find other signs of life in the universe. The present workExpand


Enhanced interplanetary panspermia in the TRAPPIST-1 system
  • M. Lingam, A. Loeb
  • Physics, Medicine
  • Proceedings of the National Academy of Sciences
  • 2017
A simple model for estimating the probability of interplanetary panspermia in the recently discovered system of seven planets orbiting the ultracool dwarf star TRAPPIST-1 is presented and it is found that panspermIA is potentially orders of magnitude more likely to occur in the TRAPPist-1 system compared with the Earth-to-Mars case. Expand
Lithopanspermia in star-forming clusters.
The lithopanspermia hypothesis in star-forming groups and clusters is considered, where the chances of biological material spreading from one solar system to another is greatly enhanced because of the close proximity of the systems and lower relative velocities. Expand
Implications of Captured Interstellar Objects for Panspermia and Extraterrestrial Life
We estimate the capture rate of interstellar objects by means of three-body gravitational interactions. We apply this model to the Sun-Jupiter system and the Alpha Centauri A\&B binary system, andExpand
Interstellar Interlopers: Number Density and Origin of ‘Oumuamua-like Objects
We provide a calculation of Pan-STARRS' ability to detect objects similar to the interstellar object 1I/2017 U1 (hereafter 'Oumuamua), including the most detectable approach vectors and the effect ofExpand
Statistical Signatures of Panspermia in Exoplanet Surveys
A fundamental astrobiological question is whether life can be transported between extrasolar systems. We propose a new strategy to answer this question based on the principle that life which aroseExpand
A brief visit from a red and extremely elongated interstellar asteroid
Observations and analysis of the object 1I/2017 U1 (‘Oumuamua) that demonstrate its extrasolar trajectory, and that enable comparisons to be made between material from another planetary system and from the authors' own, reveal it to be asteroidal with no hint of cometary activity despite an approach within 0.25 astronomical units of the Sun. Expand
1I/‘Oumuamua as a Tidal Disruption Fragment from a Binary Star System
1I/'Oumuamua is the first known interstellar small body, probably being only about 100 m in size. Against expectations based on comets, 'Oumuamua does not show any activity and has a very elongatedExpand
Transit probabilities around hypervelocity and runaway stars
In the blooming field of exoplanetary science, NASA's Kepler Space Telescope has revolutionized our understanding of exoplanets. Kepler's very precise and long-duration photometry is ideal forExpand
Chaotic exchange of solid material between planetary systems: implications for lithopanspermia.
It is estimated that of the order of 3·10(8)·l (km) could potentially be life-bearing, where l is the depth of Earth's crust in kilometers that was ejected as the result of the early bombardment. Expand
The Feasibility and Benefits of In Situ Exploration of ‘Oumuamua-like Objects
A rapid accumulation of observations and interpretation have followed in the wake of 1I `Oumuamua's passage through the inner Solar System. We briefly outline the consequences that this firstExpand