For more than three centuries, astronomers asking whether the Solar System is stable have received ever more comforting answers. Isaac Newton was not so sure. He suspected that the mutual tugs between Jupiter and Saturn would eventually wreck the planetary order, and that only divine intervention could prevent it. By the late 1700s, Laplace and […]

For the first time, astronomers have pointed NASA’s two flagship space telescopes at the same patch of sky beyond Neptune and let them work as a team. Hubble handled the visible light. Webb handled the infrared. Together, they picked out 27 previously unknown trans-Neptunian objects, or TNOs — small, icy bodies that drift in the […]

Picture a moonless night, far from any city. Look straight at the point in the sky opposite the Sun — the antisolar point, where the Sun would appear if you could see it through the Earth. There, faintly, you might make out an oval-shaped glow, 8 to 10 degrees across. For scale, that’s roughly the […]