g way that could be picked up by telescopes. Instead, Solomon used levels of CO to extrapolate the amount of hydrogen gas present. Finding one molecule of carbon monoxide could mean that there were millions more hydrogen gas molecules in the vicinity [9], and thus, was an important advancement in detecting star formation. Today, Dr. Koda uses the techniques developed by Dr. Solomon to study gas behavior and evolution in GMCs. In his studies, he uses data from CO emission to extrapolate the locations and structures of GMCs [4]. Figure 2 There are many types of radio telescopes, which use various wavelengths of the electromagnetic spectrum [10]. Recent Advances in Radio Astronomy According to Professor Koda, the field of radio astronomy is growing quite rapidly, as there have been many groundbreaking discoveries due to its use. For instance, radio astronomy could be used to find extraterrestrial life. In 2007, researchers found evidence of radio emission of the “pre-biotic” molecules, methanimine and hydrogen cyanide, which are building blocks of amino acids found in DNA. The galaxy in which these molecules were found, Arp 220, is 250 million light years away from the Milky Way galaxy and has a relatively high rate of star formation. Since these molecules are found so far from Earth, they could be a sign pointing to the existence of life outside the solar system [12]. Research has also suggested that binary star systems may be potential hosts for extraterrestrial life, and they have thus been closely studied by the use of radio astronomy. Binary star systems are two stars orbiting around a point, which is the center of their mass. In the last few years, scientists using the Very Large Array telescope in New Mexico have discovered that binary stars form from a process called “disk fragmentation,” in which the gas and dust surrounding a protostar collapse onto themselves and form another star nearby. Their recent observations confirmed the fragmentation theory [13]. Another study by scientists working at the National Radio Astronomy Observatory has found what influences the size of a newly-formed star [14]. Smaller stars like the sun form fairly quickly in their molecular clouds, with little time to grow. Yet for some larger stars, the presence of deuterium, a heavier hydrogen isotope, can provide a force that will delay the collapse of a molecular cloud, which will result in a more massive star. Discoveries in the broader field of general astronomy have also affected our knowledge of radio astronomy techniques. One example is dark matter. Though dark matter is now known as the force that pulls galaxies apart and accounts for the faster rate of expansion in the universe [11], its importance was understated and poorly understood in the past. As Dr. Koda said, “Fifteen years ago, dark matter and dark energy had yet to be better understood. [Now], it’s a very important concept, so even the most basic textbooks have to be rewritten.” The Future of Radio Astronomy Radio astronomy will become increasingly significant in studying the connection between galaxy collisions and star formations. When galaxies interact, the collision triggers a burst of star formation from gas, becoming dense and packed. Scientists are now observing collisions of galaxies, which may give insight to the Milky Way’s predicted collision with Andromeda in four billion years. From the Hubble Space Telescope’s images, it is theorized that the nearby Triangulum Galaxy will join the collision. Eventually, the three galaxies, which are currently spiral galaxies, will merge together to form a smooth elliptical galaxy [15]. Current observations and images of other galaxy collisions will help scientists draw conclusions about the blueprint of the upcoming three-galaxy collision. For example, the Atacama Large Millimeter/submillimeter Array telescope (ALMA), in its radio images of the Antennae Galaxies (which are two galaxies currently in collision 70 million light years away), provide a revelation about how stars form from galaxy interactions [16]. The radio images show the density of gas in the two galaxies and their relevance to star formation. As the field of radio astronomy is growing quickly, new breakthroughs will continue to further our knowledge of how stars form. Professor Koda remains optimistic that there will be new major discoveries as the field continues to advance. “Fifteen years ago, people said that galaxies formed by themselves,” Dr. Koda said. “In your lifetime, the view of the universe has changed. I’m hoping ten years from now, we can write one chapter in the textbooks about the formation process of stars in terms of gas behavior.” References 1. Scoville, Nick. 2009. Obituary: Philip Solomon, 1939-2008. Bulletin of the Astronomical Society, 41: 579. 2. Schombert, J. Star Formation. University of Oregon Department of Physics. . 3. Smith, H.E. Gene Smith’s Astronomy Tutorial: The Interstellar Medium. University of California, San Diego Center for Astrophysics & Space Sciences. . 4. Koda, J. 2013. Evolution of Giant Molecular Clouds in Nearby Galaxies. Ast Soc of the Pacific. 476: 49. 5. Donovan, J. Starbirth in Nearby Galaxies. . 6. Rebolledo, D., Wong, T., Leroy, A., Koda, J., and Donovan Meyer, J. 2012. Giant Molecular Clouds and Star Formation in the Non-Grand Design Spiral Galaxy NGC 6946. The Astrophysical Journal. Institute of Physics. 7. MIT Haystack Observatory. The History of Radio Astronomy. . 8. National Radio Astronomy Observatory. Prediction of 21cm Line Radiation. . 9. The Interstellar Medium: Gas. . 10. Cardiff University. Plank Mission. Millimeter Radioastronomy. . 11. National Air and Space Administration. Dark Energy, Dark Matter. . 12. Salter, C.J., Ghosh, T., Catinella, B., Lebron, M., Lerner, M.S., Minchin, R., and Momjian, E. 2008. The Arecibo Arp 220 Spectral Census I: Discovery of the Pre-Biotic Molecule Methanimine and New Cm-wavelength Transitions of Other Molecules. The Astronomical Journal. 13. National Radio Astronomy Observatory. 2013. New Studies Give Strong Boost to Binary-Star Formation Theory. . 14. National Radio Astronomy Observatory. 2013. Starless cloud cores reveal why some stars are bigger than others. . 15. National Air and Space Administration. NASA’s Hubble Shows Milky Way is Destined for Head-On Collision. 2012. . 16. Atacama Large Millimeter/submillimeter Array. ALMA view of the Antennae Galaxies. . 17. Koda, Jin. Personal Interview. 30 Jan 2014. 25