In my first post about the Berlin Fulbright Seminar, I mentioned that I had the awesome opportunity to talk about my work in front of about 600 people. Talking about radio astronomy and astrochemistry to a group that was made up of many people who had never heard about either of these areas of science was a lot of fun, and preparing for the talk forced me to think about how to convey radio astronomy as an intriguing and significant field.
Below, I've included the slides from my presentation, accompanied by a transcript of what I told the audience. (Clicking on the image of a slide will allow you to view a larger version of it.)
When I was a kid, I thought that the black spaces between the stars were empty, and until about 50 years ago, many astronomers thought the same. They believed that the radiation of interstellar space was so extreme that it would be impossible for any molecules to exist there. Although interstellar space is quite empty by Earth’s standards, the advent of radio astronomy has led to the revelation of an invisible universe.
Radio astronomy was born in the 1930s, and it has enabled us to see wavelengths of light that are invisible to our unaided eye. Before radio astronomy, our universe looked a lot blacker.
Consider a galaxy floating in a plane of other galaxies outside our own Milky Way. Using optical telescopes, we see a spiral galaxy in which interstellar spaces are evident among bright stars.
However, using a radio telescope, we see that this galaxy is much larger than perceived before. Furthermore, we see that this galaxy is populated by molecular gas clouds. These two images—to the same scale—show a galaxy of a much different size and composition depending on the lens through which it is viewed.
Radio images are made possible through the use of radio telescopes, such as the Radioteleskop Effelsberg just an hour-and-a-half southwest of Cologne. Using instruments like the one at Effelsberg allows astronomers to learn about the physical and chemical make-up of distant stars and galaxies. This is something that is limited by conventional optical scopes.
To collect radio data, the dishes of radio telescopes are pointed towards a region of the sky which is emitting radio waves. These waves travel hundreds and even thousands of light-years to Earth, where they are collected by a dish and reflected into a receiver. From there, astronomers can untangle the chemical make-up of a target object using the aid of computers.
From radio telescopes, we receive a type of fingerprint in the form of a spectrum. Just like when investigating a crime scene, we can use this fingerprint to learn more about a subject by cross-referencing it with a database. Gathering information for this database is part of my task as a Fulbright fellow at the University of Cologne.
At the University of Cologne, I gather and analyze spectral data of complex organic molecules that might be found in space. These molecules are interesting because they may answer questions regarding the fundamental chemistry of the early universe and may even give some insight to the evolution of the chemistry that led to life as we know it. Many astronomers also hope that astrochemistry will help us discover new lifeforms.
My husband and I are very happy that as part of the Fulbright adventure, we have encountered our own new lifeform.
Thank you. The only thing that will make this better is if when he shows up next month, he looks less like an extraterrestrial.
To study complex organic molecules, I pump them (as a gas) into a glass cell, which is placed under vacuum to have a pressure of about one-millionth of that in this room. From there, I measure the rotations and vibrations of these molecules, creating a spectrum that simulates what such a molecule would look if observed in space using a radio telescope.
The results of my work will be compiled into the Cologne Database for Molecular Spectroscopy, or CDMS. The CDMS is perhaps the most widely-used molecular database for radio astronomers, and has been instrumental in helping astronomers tune into the radio waves of our universe. To date, nearly 200 molecules have been identified in interstellar space where the existence of such molecules was formerly thought to be impossible.
For all of us, Fulbright is about crossing international and cultural borders to learn more about our place in this world; for me, it is also about crossing interstellar borders, learning about our place in this universe.