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13-17 May 2019, Leiden Observatory


To determine what techniques and approaches are the most expedient at determining exocomet composition and what future work would most benefit our understanding of how exocomets affects exoplanet atmospheres and the emergence of life throughout the Universe.


Which systems provide the best candidates for follow-up observations?

Are there any other gas tracers other than the CO molecule which are worth pursuing?

Solar System Comets

How unique are Solar System comets?

Do exocomets have a similar composition to the comets in the Solar System?

Exoplanet Atmospheres

Can we measure the impact of exocomets on planetary atmospheres?

How is the evolution of exoplanet atmospheres impacted by exocomets?


What role do exocomets play in the formation of planetary systems?

What organic molecules might we be able to detect with ALMA?


Do impacts help or hurt in kick starting life?

Are we able to detect complex molecules which may have originated from exocomets? Which ones?

Why have a workshop on Exocomets?

Comets are small icy bodies which vaporise on close approach to the Sun leaving behind a tail of dust and gas. Together with asteroids they are regarded as the unused building blocks of the Solar System, providing astronomers with pristine samples of the formation and evolution conditions of the early Solar System. Much is to be gained by studying their composition as they provide important clues to the formation of life on Earth through the delivery of complex organic molecules and large quantities of water which may have laid the seeds of early organic chemistry on Earth.

Young stellar systems, some of them many light years away, resemble the early Solar System by showing the hallmarks of being surrounded by a vast number of comets that we are now able to detect. These comets orbiting other stars, referred to as exocomets, give us the important foundation for which to make a comparison with the comets in our Solar System and allow us put their composition in perspective. Exocomets also provide us with information valuable for understanding the composition of exoplanet atmospheres and may help us understand the early chemistry of Earth.

Despite the great opportunity for exocometary scientists, the Solar System comet community, the exoplanet atmosphere researchers, disk community and astrobiologists to learn from each other and exchange experiences and techniques, there has been surprisingly little collaboration between these communities. This Lorentz workshop will, for the first time, bring experts from each of these communities together in the same room to share ideas and exchange knowledge which will undoubtedly foster new insights and develop fresh approaches to a very timely topic.

Workshop program

Please have a look at our program. We have speakers from the exocomet, Solar System, exoplanet, disk and astrobiology communities.

We intend to:

Summarise the most recent results from exocomet research and the Rosetta mission to give attendees a common foundation.

Brainstorm new methods for determining the composition of exocomets, soliciting advice from the Solar System community on what chemical species to look for.

Explore new avenues for determining exocomet composition. E.g. what organic molecules might we be able to detect with ALMA and what JWST observations would be most beneficial for determining exoplanet composition?

Form working groups to develop different approaches to determining exocomet composition using a collection of publicly available exocometary data.

Create links between the exocomet and atmosphere communities to be able to predict the spectra of impact dominated planets in order too look for them with e.g JWST or ELT.

Explore how realistic the new proposed pathways that can lead to the building blocks of life (DNA, amino acids) are using the exocomet modeller/observer inputs to feed into the astrobiologist (chemical) models.

Determine what theoretical and observational work would be most beneficial to the field. Form collective of researchers willing to further collaborate on the most pertinent work beyond the workshop.

Discuss how ESA missions can contribute to this field, both from comet results from Rosetta and by looking forward to possibilities for observing exocomets with CHEOPS, PLATO and ARIEL.

Through the group work we wish to establish future collaborations between the different communities beyond the workshop.


Paul A. Wilson
University of Warwick
Sarah Rugheimer
University of Oxford
Quentin Kral
Paris Observatory
Pic - Snodgrass
Colin Snodgrass
University of Edinburgh
Melissa K. McClure
Anton Pannekoek Institute

How to get there

Closest airport is Amsterdam Schiphol. From there it is a quick (~20 min) train ride to Leiden, followed by a walk to the workshop venue.

Workshop venue

3rd Floor Oort Building
Niels Bohrweg 2