Watch a video replay of NASA’s exoplanet announcement

Scientists examining data from the Cassini mission’s final months reported this week unexpected measurements of Saturn’s gravity field and outer atmosphere, suggesting they may have to revisit theories about the planet’s rings and the forces that generate magnetic fields.

A layer of fog intruding on Vandenberg Air Force Base in California kept nearby observers from seeing any sign of Saturday’s predawn launch of an Atlas 5 rocket carrying a robotic NASA probe to Mars. The only images of the Atlas 5’s fiery takeoff came from remote cameras placed at the launch pad, or from distant viewing points away from the poor visibility.

NASA’s Transiting Exoplanet Survey Satellite, built to find planets around other stars that are close enough for detailed follow-ups by future telescopes, launched Wednesday into a unique high-altitude orbit on top of a SpaceX Falcon 9 rocket from Cape Canaveral.