Mass Extinctions and The Sun's Encounters with Spiral Arms

Abstract

The terrestrial fossil record shows that the exponential rise in biodiversity since the Precambrian period has been punctuated by large extinctions, at intervals of 40 to 140 Myr. These mass extinctions represent extremes over a background of smaller events and the natural process of species extinction. We point out that the non-terrestrial phenomena proposed to explain these events, such as boloidal impacts (a candidate for the end-Cretaceous extinction), and nearby supernovae, are collectively far more effective during the solar system's traversal of spiral arms. Using the best available data on the location and kinematics of the Galactic spiral structure (including distance scale and kinematic uncertainties), we present evidence that arm crossings provide a viable explanation for the timing of the large extinctions.

Latex, aaspp4.sty, 8 pages, 2 Postscript figures, to appear in New Astronomy 3 (1998) 51-56

Cited by in corpus (30)

• Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models
• The Spiral Structure of the Milky Way, Cosmic Rays, and Ice Age Epochs on Earth
• Direct determination of the spiral pattern rotation speed of the Galaxy
• Ice Age Epochs and the Sun's Path Through the Galaxy
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. VIII. Identification of 44 newly detected hard X-ray sources
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. III. Observations of seven southern sources
• IGR J18483-0311: an accreting X-ray pulsar observed by INTEGRAL
• The evidence for and against astronomical impacts on climate change and mass extinctions: A review
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. X. A new multi-year, multi-observatory campaign
• Solar System Physics for Exoplanet Research
• A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun: I. Atmospheric parameters and color similarity to the Sun
• Hard X-ray flares in IGR J08408-4503 unveil clumpy stellar winds
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. IV. A study of six new hard X-ray sources
• On The Timescale Forcing in Astrobiology
• Fermi's Paradox - The Last Challenge for Copernicanism?
• Astrobiologically Interesting Stars within 10 parsecs of the Sun
• Lunar Palaeoregolith Deposits as Recorders of the Galactic Environment of the Solar System and Implications for Astrobiology
• Corotation: its influence on the chemical abundance pattern of the Galaxy
• The "Carina Flare" Supershell: Probing the Atomic and Molecular ISM in a Galactic Chimney
• Impact cratering and the Oort cloud
• Assessing the influence of the solar orbit on terrestrial biodiversity
• Galactic Punctuated Equilibrium: How to Undermine Carter's Anthropic Argument in Astrobiology
• Taming the Runaway Problem of Inflationary Landscapes
• Astrobiological Complexity with Probabilistic Cellular Automata
• Is CGCS 5926 a symbiotic X-ray binary?
• Short-term Variations in the Galactic Environment of the Sun
• Searching for supergiant fast X-ray transients with Swift
• The genetic signature of (astronomically induced) life extinctions
• The lunar surface as a recorder of astrophysical processes
• The SOL $\text{(Solar Origin and Life)}$ Project: Detailed characterization of candidates for the ZAMS and Subgiant stages