Better Astrochemistry Through ALMA | Out Of This World Weekly

Years ago, scientists thought that space was so harsh that molecules would not form.  Instead of complex molecules forming in space, they would immediately be broken apart by intense energies and cold voids.  We have discovered that this is not true.  Complex molecules can exist in space and now we are going to be able to detect them with the technology being implemented at the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile.  New technology is allowing astrochemists to speed up the process of analyzing chemicals based on their signature elecromagnetic emissions.  Over 170 chemicals have already been discovered through intense study, yet the amount of time and effort put into these discoveries has been intense.  With this new technology, we should be able to look at a nebula and quickly determine what chemicals are there and which are not.

If we are to investigate the universe, we don’t just want to know the distances, energies, and masses involved.  We want to understand what a place is like and understanding what chemicals and molecules are there is key to this type of understanding.  We need to know things like “Is there water there?”, or “Is the environment so acidic or toxic that our basis of life could never exist or survive?”.  Scientists have also been able to find many of the building blocks of life just floating freely in cloudy nebulae and this type of information is essential in the understanding of how life forms.  By understanding large gaseous nebulae, we can better understand the chemicals and molecules involved in the formation of stars and planets.  A better understanding of the chemical composition of the universe will ultimately give us a greater knowledge of exactly what role chemistry plays on a universal scale. 

To be able to determine what chemicals exist in a region of space, scientists first determine the spectral lines associated with a variety of chemicals.  When these chemicals undergo changes they give off radio waves in very specific frequencies.  Then pictures of the region of space are taken with high precision telescopes and compared with those characteristic spectral lines.  If they match up perfectly, then that chemical is present in that region of space and if they don’t match up, then they are not present.  ALMA is allowing for a much more sensitive analysis of the chemical emissions and it is also allowing for a much faster analysis.  This is key because recently only a few chemicals have been found per year for the last decade.  We have already used this technology to understand the basic composition of the outer planets, asteroids, and comets.  The knowledge that planets outside our solar system have water in their atmospheres is also due to this technology.  As our ability to quickly understand what chemicals are present in our own and in distant galaxies increases, we are certainly going to obtain a greater understanding of the workings of the universe as a whole.