In a popular science talk on June 3 Leonardo Testi compared the chemical complexity on Earth, for example in the human body, with the very different one found in the Sun and the gas giants, and posed the question of how they are linked. What is needed for a habitable planet is a finely tuned source of energy, liquid water and complex molecules. It is known that the first simple life forms existed soon after the formation of Earth. The process from a diffuse cloud to a sun and a planetary system is also a process from atoms and simple molecules to life.
One of the questions the programme has worked with is how much of those processes are happening in the gas phase and how much in the solid state, i.e. how far the complexity of molecules goes in the interstellar medium. As for now, the most complex molecules that have been found around protostars consist of 10–11 atoms. To be able to watch the dust molecules in the gas clouds, radio telescopes observing millimeter wave lengths are used. To avoid disturbances from the atmosphere telescopes are built in special places, such as the ALMA telescope in the Atacama desert in Chile, one of the driest places on earth.
Molecules such as glycolaldehyde, formamide, acetone and ethyl formate have been discovered, but not yet amino acids. Those consists of an amine group and a carboxylic acid group, with side-chains. In the form of proteins they are the second-largest component of the human body, after water. To find amino acids is one of the goals of the ALMA telescope and of radio astronomy. The three themes of the GoCAS programme have been: to organize what we know of complex molecules and how molecules are formed in an interstellar medium, to review current and future techniques to observe complex molecules and planetary systems, and to discuss how planets are actually formed and how common our own solar system is.
Read more about the programme
Text and photos: Setta Aspström