Effects of high-energy astrophysical events on habitable planets

Abstract

With the possible exception of meteor impacts, high-energy astrophysical events such as supernovae, gamma-ray bursts (GRB) and flares are usually not taken into account for biological and evolutionary studies due to their low rates of occurrence. We show that a class of these events may occur at distances and time scales in which their biological effects are non-negligible, maybe more frequent than the impacts of large asteroids. We review the effects of four transient astrophysical sources of ionizing radiation on biospheresstellar flares, giant flares from soft gamma repeaters (SGR), supernovae and GRB. The main damaging features of them are briefly discussed and illustrated. We point out some open problems and ongoing work.

Colloquium: Physical constraints for the evolution of life on exoplanets

“…The second aspect that we highlight concerns the effect of planetary magnetic fields in regulating the amount of cosmic rays that reach the surface. This is particularly relevant since high-energy radiation can drive the radiolysis (decomposition via radiation) of complex biomolecules (Dartnell, 2011;Horvath and Galante, 2012). It is wellknown that the planet's magnetospheric shielding (for deflecting charged particles) influences the amount of radiation that reaches the surface (Grießmeier et al, 2009), but more recent studies have revealed that the dependence on the magnetic moment M p is very sensitive to the atmospheric column density (Atri et al, 2013).…”

Solar system exposure to supernova γ radiation

“…The predicted effects of hard photon radiation on Earth include temporarily elevated levels of cosmogenic isotopes such as 14 C, 10 Be and 36 Cl, ionization of N species in the atmosphere, depletion of the ozone layer, increased UV radiation at the Earth's surface and delivery of fixed N to the Earth's surface. There is a rich literature describing these potential effects (Terry and Tucker, 1968; Ruderman, 1974; Clark et al ., 1977; Rood et al ., 1979; Thorsett, 1995; Scalo and Wheeler, 2002; Gehrels et al ., 2003; Melott et al ., 2003, 2005; Thomas et al ., 2005; Galante and Horvath, 2007; Martín et al ., 2009; Thomas, 2009; Horvath and Galante, 2012; Gowanlock, 2016). If sufficiently intense, the radiation events can also affect other solar system atmospheres and surfaces (Duggan et al ., 2001; Scalo and Wheeler, 2002; Fox et al ., 2017).…”

Terrestrial effects of moderately nearby supernovae

“…Supernovae have been considered as a possible cause of terrestrial extinctions and lesser events for a long time, at least since Schindewolf (1954). Later work was done by Ruderman (1974); Whitten et al (1976); Gehrels et al (2003); Horvath and Galante (2012); ; Melott et al (2015Melott et al ( , 2017. Due to recent detections, there have been new computations which shed light on the effects of events at moderate distances, such as 150 to 300 light years.…”