He is now in his second stint as a professor at the University of Chicago. Prior to that, he worked at the University of Notre Dame for eight years, during which he earned a PhD in astronomy from the university's Center for Astrophysics. Afterward, he held the post of professor of astronomy at the University of Arizona for two years, followed by another five years as a professor at the University of Texas at Austin. His contributions in this field include the development of a mathematical model describing the shape of spiral galaxies, which helped scientists to better understand the cause of dark matter's motion in the universe. In addition, he pioneered the creation of several computer software programs to better measure the velocity of stellar motions in the universe. This includes the SparsePak program used to create a three-dimensional map of the universe that was featured by Scientific American magazine in October 2009. He has received numerous awards for his work in astronomy, including the Sloan Foundation Fellowship and was named by Time magazine as one of the "Top 100 Living Computers." He is also an active researcher in the fields of solar wind, solar storms and space weather. His current project includes using ground-based telescopes to study the aurora that forms above the magnetosphere of the Earth. Auroras are among the most powerful natural light sources and are often visible in the polar regions of the night sky. Some auroras form at altitudes of more than a hundred thousand miles, but it has only recently been possible to capture images of these events. These light sources play an important role in space weather, and their study is made possible by new instruments that have been developed by JAXA. In January 2007, he and his colleagues observed the Northern Lights for almost three hours, the longest continuous observation of the lights ever made at the time. Auroras usually form when charged particles are accelerated up to such high energies as they encounter a magnetic field in space. This results in an electromagnetic radiation called a cyclotron emission, which can produce light displays at altitudes from just a few hundred kilometers to a few hundred thousand kilometers. These observations by JAXA ground-based telescopes are part of a project to measure the properties of auroras at different altitudes. For example, some auroral events were previously known to produce electron beams with energies exceeding one million electron volts (1 million electron volts = 1 MeV). "Observing the auroras at a higher altitude, such as about 100 kilo-meters, is the way to study the acceleration of electrons and ions, and the magnetic fields that confine them," Dr. Tsuboi said. Until recently, though, such a level of resolution was not possible. However, a new instrument called the Space-borne Electron Proton Alpha Monitor (SEPAM) was developed to measure the electron energy distribution from these events. The SEPAM data also enable scientists to study the relationship between the ion and electron populations, which can help to better understand the acceleration mechanisms. Explore further In search of magnetically active planets: First in a three-part series Provided by JAXA