The world of astronomy mourned the recent passing of Dutch-American astronomer Maarten Schmidt, the first person to measure the distance to a quasar. His groundbreaking work in the 1960s greatly expanded the size of the known universe, providing one of the first clues that the Big Bang theory was correct. Schmidt died on Sept. 17 at his home in Fresno, California. He was 92 years old.
Dr. Schmidt’s discovery of what was then among the farthest known objects in the universe answered one of the great conundrums of postwar astronomy, and like all great breakthroughs, it opened the door to a whole host of new questions. Advances in radio technology during World War II allowed scientists in the 1950s to probe deeper into the universe than they could with traditional optical telescopes. But in doing so they picked up radio signals from a plethora of faint or even invisible, but intensely energetic, objects that did not fit with any conventional category of a celestial body.
Researchers called them “quasi-stellar radio sources,” or quasars, for short — even though no one could figure out what a quasar was. Many thought they were small, dense stars nearby, within the Milky Way.