[seminar] Astro Journal Club on 11 March

[Oskari Miettinen]

Dear all,

The Astro Journal Club will be held on Wednesday at 10:15 in the seminar
room F-201 of the Physics Department. This time we will discuss about the
possible connection between the Galactic dark matter and mass extinctions.

Presenter: Oskari Miettinen
Paper title: Disc dark matter in the Galaxy and potential cycles of
extraterrestrial impacts, mass extinctions and geological events
Author: Rampino, M. R.

Abstract:
A cycle in the range of 26-30 Myr has been reported in mass extinctions,
and terrestrial impact cratering may exhibit a similar cycle of 31+/-5
Myr. These cycles have been attributed to the Sun's vertical oscillations
through the Galactic disc, estimated to take from 30 to 42 Myr between
Galactic plane crossings. Near the Galactic mid-plane, the Solar system's
Oort Cloud comets could be perturbed by Galactic tidal forces, and
possibly a thin dark matter (DM) disc, which might produce periodic comet
showers and extinctions on the Earth. Passage of the Earth through
especially dense clumps of DM, composed of Weakly Interacting Massive
Particles (WIMPs) in the Galactic plane, could also lead to heating in the
core of the planet through capture and subsequent annihilation of DM
particles. This new source of periodic heating in the Earth's interior
might explain a similar 30 Myr periodicity observed in terrestrial
geologic activity, which may also be involved in extinctions. These
results suggest that cycles of geological and biological evolution on the
Earth may be partly controlled by the rhythms of Galactic dynamics.

Link to the paper: http://adsabs.harvard.edu/abs/2015MNRAS.448.1816R

Hope to see you all on Wednesday!

Best regards,
Oskari