Quasar’s Light Echoes After 6.73 Years

Astronomers using the 1.2-meter Whipple Observatory to follow the brightness of a lensed galaxy for 14.5 years have calculated that the time delay between light arriving along the shortest and farthest paths is 6.73 years. Plus, DART, Hayabusa2, Juno, fast radio bursts, and This Week in Space History, we look back at NASA’s 1990s attempts to reach Mars.