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NASA’s release of the stunning images from the James Webb Space Telescope signals the start of a new era of space-borne astronomical observation. With seven times more light-gathering power than the Hubble telescope, its predecessor, the Webb is opening our eyes to the cosmos as never before possible and will give us new information about faraway worlds, the formation of galaxies and the furthest reaches of space. But the Webb telescope also exemplifies a crucial practical point: It shows why robotic explorers are superior to human astronauts in deepening our understanding of the universe.
Consider the new telescope’s location in space. The Hubble had to remain just 335 miles above the Earth because NASA had only the astronaut-crewed space shuttle to launch it; it therefore suffered interference from light reflected off the planet’s surface and from the obstacle of the Earth itself. It was as if astronomers had placed one of Hawaii’s mighty Keck telescopes amid the lights of New York City instead of on a dark mountaintop in the Pacific. The Webb array, by contrast, orbits at a deep, dark point called “L2,” almost a million miles beyond Earth—which it can do because it was launched by an uncrewed rocket and is designed to maintain itself with guidance from controllers on Earth but without hands-on human intervention. (An unusually large grain of space dust did some damage to one of the telescope’s 18 mirrors in May, but that has not so far affected its overall operation.)
