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PX443 Planets, Exo-Planets and Life

Lecturers: Dan Bayliss and Farzana Meru
Weighting: 15 CATS

The detection of planets orbiting stars other than the sun is technically challenging and it was not achieved until 1995. This module looks at how exoplanets are now being discovered in large numbers and how these discoveries are challenging existing theories of planet formation and evolution. Various methods of detection are considered, as well as methods used to determine physical properties such as temperature, density and composition. We explore likely physical explanations for the observed properties and identify questions that remain open in this active research field. Finally, we consider the prospects for detecting life on distant planets.

To explore the impact of recent advances in the field on our understanding of planet formation, structure and evolution. To illustrate how established theories can be challenged using careful experimentation.

At the end of this module you should:

  • Be able to describe the interior, atmospheric composition and structure of the Solar System planets
  • Be aware of the experimental methods used to search for extra-solar system planets
  • Understand the models being developed to describe planet formation and structure
  • Be aware of the wide range of planets observed and of the open questions
  • Be familiar with current thinking on the conditions needed for life to evolve and be able evaluate critically the prospects for the discovery of extra-terrestrial life


  • Geometry and contents of the Solar System; the interior, atmospheric composition and structure of the Solar System planets;
  • Models of planet formation developed to explain the observed properties of the Solar System: accretion discs, dust coagulation, planetesimal formation, gas accretion, orbital evolution, disc evaporation;
  • Challenges and opportunities presented by exoplanetary systems; Debris discs and protoplanetary discs;
  • Observational techniques relevant to exoplanets: precision radial velocities, transits, microlensing, direct imaging, polarimetry, astrometry, Rossiter-McLaughlin effect, transmission spectroscopy;
  • Physical properties of exoplanets: mass, radius, temperature, albedo, composition, irradiation, evaporation, meteorology, orbital orientation, dynamical stability;
  • Challenges to planet formation theory: migration, evaporation, system geometry, free-floating planets. Future observational techniques: extreme adaptive optics, nulling interferometry;
  • Conditions for life: definition of life, extremophiles, energy sources, carbon chemistry, water, habitable zone, alternative habitats; detection of extra-terrestrial life: in-situ measurements, atmospheric spectroscopy, biomarkers, planned space missions, Drake equation, SETI.

Commitment: 30 Lectures

Assessment: 2 hour examination

The module has a website.

Recommended Texts:
R Dvorak (Ed.), Extrasolar Planets, Wiley-VCH;
I de Pater and JJ Lissauer, Planetary Sciences, CUP;
M Perryman, 2011, The Exoplanet Handbook, CUP;
Philip J. Armitage, Astrophysics of Planet Formation, CUP

Leads from: