Q&A with Scott Bolton, principal investigator on NASA’s Juno mission

NASA’s Cassini spacecraft sped through a gap between Saturn and its rings for the second time Tuesday after data from the probe’s first perilous passage through the unexplored region last week found it to contain fewer potentially hazardous dust particles than expected.

NASA’s Perseverance rover, set for liftoff Thursday on a journey to Mars, posed some unusual challenges for launch crews working with the robot’s plutonium-fueled power generator, but United Launch Alliance’s Atlas 5 rocket is uniquely suited for the job, the company’s CEO says.

The first hints of dramatic cliffs, chasms and craters are showing up in new imagery of Pluto and its Texas-sized moon Charon as NASA’s New Horizons spacecraft prepares to bolt by the icy worlds Tuesday.