Space telescopes, planet formation
and the ingredients for life.

About Me

I am an astronomer at the Space Telescope Science Institute (STScI) located in Baltimore, Maryland. I work on the formation of planets and the origin of our own Solar System. One particularly exciting question is how common the ingredients for life are such as water) and whether they naturally evolve as part of new planets.

I also work as a James Webb Space Telescope Project Scientist at STScI. JWST is the scientific successor to the Hubble Space Telescope and the Spitzer Space Telescope. As the largest optical/infrared telescope ever put into space, it is expected to spot the most distant galaxies in the Universe, dust and molecular gas around young stars in the process of making their own planetary systems, and, not least, to characterize the atmospheres of exoplanets.


I study the formation of planets in around young stars. The aim is to understand how the Solar System formed, how extra-solar planets form and how the chemical composition of their surfaces and atmospheres develop. The Solar System is 4.6 billion years old, an ancient place, a full third of the age of the Universe. It contains perhaps up to 20 objects - planets, moons and the new class of dwarf planets - large enough that they can be considered "worlds". The Solar System is also littered with rocks and snowballs, with sizes ranging from mountains to boulders and even the tiny flecks that can be seen as meteors when entering the Earth's atmosphere. While the surface of the Earth is constantly being remodeled by erosion, volcanic eruptions and the movement of tectonic plates, some of the rocks of the Solar System have been orbiting the Sun virtually unchanged for billions of years.

They carry locked within them clues to how the Solar System formed. They tell a story of a nebula, hot with activity, bathed in ultraviolet radiation from an infant star. It was rich place, filled with water vapor and other more noxious gases, some of which must have contributed to the organic soup of Earths first oceans that gave rise to the first life forms. It also tells a violent story of the planets being formed from dust. Beginning with tiny smoke-like grains of minerals and carbon, growing and sticking together like snow flakes, ending with planetesimals up to a thousand miles across, some only to be destroyed in massive collisions. Those that survived formed the planets and moons we know today but with an amazing variety, from the icy geysers of Enceladus, the sulphuric hell of Io, the waters of Earth and the barren, rocky wasteland of Mercury. Such an incredible spectacle, how exciting it would be to have been around then, to witness the incredible formation of the Solar System, to understand the diversity and ultimately discover if the same story unfolds around many young stars - because if it does - then Earth is probably only one of many life-bearing worlds in the Universe.

Artist's impression of a protoplanetary disk

Water and organic molecules in planet-forming matter

Data and Tools

Here you will find links to download software and a number of astronomical databases of infrared spectroscopy of disks and young stars. The data are free to use with appropriate reference to their original publication.

RADLite (download)

RADLite is a fast, easy-to-use line raytracer for axisymmetric geometries, developed as an add-on to the widely used RADMC continuum Monte Carlo code by Kees Dullemond. Written Fortran with an IDL wrapper, It is optimized for rapid rendering of the complex infrared spectra of molecular gas in protostars and protoplanetary disks, using input from the HITRAN database, but is inherently versatile. It includes IDL scripts for simulating line and line imaging observations. The code is described in greater detail in: Pontoppidan et al. 2009, ApJ.

VLT-CRIRES database of protoplanetary spectra (download)

Here you will find fully processed L- and M-band high resolution spectra of protoplanetary disks and young stellar objects. The data were obtained during 2007-2009 as part of a large ESO program 179.C-0151 (The planet-forming zones of disks around solar-mass stars) and 082.C-0432 (The distribution of water vapor in the terrestrial zones of protoplanetary disks). In total, the database includes CRIRES 2-5 micron data collected during 30 nights of VLT time.

Team: The CRIRES protoplanetary disks program is a collaboration between investigators at various European and US institutions, including the California Institute of Technology, Leiden University, Max-Planck Institute for Extra-terrestrial Physics, UCLA, ESO and the Space Telescope Science Institute. Team members (original affiliations):
Ewine van Dishoeck (Leiden/MPE), Klaus Pontoppidan (STScI), Geoffrey Blake (Caltech), Joanna Brown (CfA), Gregory J. Herczeg (MPE), Rachel Smith (UCLA), Jeanette Bast (Leiden), Avi Mandell (NASA GSFC), Alain Smette (ESO), Hans Ulrich Kaufl (ESO), Wing-Fai Thi (Edinburgh/Grenoble), Bill Dent (Edinburgh), Isa Oliveira (Leiden)

Spitzer-IRS database of high-resolution spectra protoplanetary disks (download)

This page contains fully reduced Spitzer-IRS high resolution spectra of disks from the Spitzer archive. The spectra are reduced using my pipeline CHIP (Caltech High-Res IRS Pipeline). It makes extensive use of standard star spectra to achieve the highest possible fidelity to uncover faint emission lines on top of bright continua. These spectra were used to characterize the spectra of water and other molecules from disks around young solar-type stars (e.g., Pontoppidan et al. )

VLT-ISAAC database of circumstellar ices (download)

This page contains fully reduced spectra, obtained as part of a large ESO VLT program (164.I-0605) to observe ices toward (mainly low-mass) protostars in the 3-5 micron region with the near-infrared ISAAC spectrometer on the VLT. The spectra contain the 3.1 micron water ice band and the 4.7 micron CO ice band. In general, the former was observed using the low resolution mode of ISAAC, resulting in resolving powers of R~600-1,200 (depending on slit width), while the latter used the medium resolution mode, leading to resolving powers of R~5,000-10,000. The data were obtained between 2000-2003. The Spitzer c2d spectroscopic sample was to a large degree based on the original ISAAC dataset.

Team: Ewine van Dishoeck, Emmanuel Dartois, Klaus Pontoppidan, Wing-Fai Thi, Louis d'Hendecourt, Adwin Boogert, Helen Fraser, Willem Schutte, Xander Tielens


Klaus Pontoppidan
Space Telescope Science Institute
3700 San Martin Drive
Baltimore, MD 21030
410 338 4744
pontoppi at