Exoplanets: The search for planets beyond our solar system

Report of a seminar held in London on 15 June 2011 to discuss progress, recent results and future projects in the discovery and study of planets orbiting stars other than our Sun.

Exoplanets: The search for planets beyond our solar system

The existence of worlds other than our own has always excited popular interest. This curiosity has grown over the past two decades since the first discovery of planets outside our solar system. 

Using ground-based telescopes and space missions,more than 700 extrasolar planets – or “exoplanets” – have now been identified, and thousands more candidates are awaiting confirmation. 

Advances in technology, combined with ingenious detection methods, have not only speeded up the rate at which exoplanets are being found, but have also enabled scientists to infer many of their characteristics, including atmospheric composition, size, mass and temperature. 

In this way, they are starting to construct a picture of how planets form and what the galactic planetary population looks like. Further scientific and technological progress should give us a clearer idea of how common Earth-like planets are, and whether they could harbour life.

This seminar explored the various methods used to detect exoplanets, describing some of the current and proposed searches. 

The speakers at the seminar highlighted some of the most significant discoveries and technical advances, and speculated on future prospects for exoplanet science. 

Prof. Dame Jocelyn Bell Burnell, president of the Institute of Physics, who is well known for her role in the discovery of rotating neutron stars, or pulsars, chaired the seminar. 

Prof. Hugh Jones of the University of Hertfordshire gave an overview of exoplanet discovery and described one of the main techniques employed, the radial velocity method. 

Dr Suzanne Aigrain of the University of Oxford explained the role of the other main technique used so far in exoplanet hunting – the transit method – and summarised how scientists are slowly building up a view of planetary demographics across our galaxy. 

Dr Giovanna Tinetti from University College London discussed how the transit method could be employed to analyse and study the atmospheres of exoplanets, thus establishing a new field of galactic planetology and paving the way to identify planets that might be hosting life.