Who is this?
Core group:

Melvyn B. Davies

Anders Johansen
Birger Schmitz

Ross Church
Lennart Lindegren
Paul McMillan

Alex Mustill (Senior research fellow)

Giorgi Kokaia (PhD student)
Simona Pirani (PhD student)


Yann Alibert
Philip Armitage
Willy Benz
Andrew Levan
Chris Lintott
Cole Miller
Richard Parker
Giampaolo Piotto
Philipp Podsiadlowski
Serena Repetto
Steinn Sigurdsson
Nail Tanvir
Chris Tout
Dimitri Veras
Lund Observatory
Local events
Lund University

IMPACT: Comets, asteroids and the habitability of planets

IMPACT is a project grant funded by the Knut and Alice Wallenberg Foundation (2015-2020).

The Universe is a dangerous place. Close encounters with other stars send comets from the Solar System's Oort Cloud into Earth-crossing orbits. Gravitational interactions within the asteroid belt also scatter asteroids onto Earth-crossing orbits. Inevitably, some of these comets and asteroids strike the Earth. Their impacts have profound effects, both on the climate and on the evolution of life on Earth. Stars passing through the spiral arms of the Galaxy encounter an increased rate of nearby supernova explosions whose radiation may destroy the protective ozone layers of habitable planets similar to the Earth. Using data from the European astrometric space mission Gaia, which launched successfully in December 2013, we will determine the spiral arm pattern of our Galaxy and the Sun's orbital motion within the Galaxy. Thus we will be able to calculate when the Sun passed through the spiral arms and compare these times to the occurrence of large impacts, mass extinctions and increases in the flux of cosmic rays coming from supernovae. Furthermore IMPACT will make use of two unique facilities located in Lund: the Medicon Village Astrogeobiological Laboratory (MV-AGB), which will be used to search in sedimentary rock samples for meteoritic spinel minerals which can be used to determine the geological history of impact rates and cosmic ray fluxes; and the Luis W. Alvarez Iridium Coincidence Spectrometer (LA-ICS) which will be used to analyse sedimentary rock for iridium originating from impacting bodies. This geological data will be exploited and interpreted in an astronomical framework by comparing with computations of impact rates and supernova rates on the Earth as well as on habitable planets around other stars.

Funding from the Knut and Alice Wallenberg foundation allows us to create a unique research environment where astrophysicists and geologists come together to understand how impacts and cosmic rays affect the habitability of the Earth and other planets. The project consists of three components:

  • Determination of the impact history of the Earth

  • Calculation of bombardment rates on habitable planets around other stars

  • Investigation of how the Galactic environment affects habitability

Lund Observatory, Box 43, SE-221 00 Lund, Sweden
Visiting address: Sölvegatan 27
Phone: +46 46 22 27300, Fax: +46 46 22 24614
Publisher: Melvyn Davies
E-mail: webmaster@astro.lu.se
Last updated: 2016 August 4