Concerns about the health of the Juno spacecraft’s main engine have compelled NASA managers to keep the research probe in its current arcing, high-altitude orbit around Jupiter, a decision that will delay the full science return from the $1.1 billion mission but should still allow it to meet all predetermined objectives.
Updated at 3:30 p.m. EST with additional comments from Scott Bolton. NASA’s Juno spacecraft made a high-speed pass less than 3,000 miles over Jupiter’s turbulent clouds Thursday, taking dozens of pictures, measuring radiation and plasma waves, and peering deep inside the planet’s atmosphere, but officials still have not cleared the orbiter’s main engine for a planned maneuver to position the probe for improved science observations. As Juno prepared for Thursday’s encounter, managers weighed whether to cancel an engine burn originally scheduled for October to reshape the craft’s orbit. The solar-powered spacecraft made its closest approach about 2,670 miles (4,300 kilometres) over Jupiter’s cloud tops at 1257 GMT (7:57 a.m. EST) Thursday. NASA said all of Juno’s science instruments and its JunoCam color camera were operating during the flyby, and the data is being returned to Earth. Juno zipped by Jupiter at a relative velocity of about 129,000 mph (57.8 kilometres per second), approaching the planet over its north pole and departing over the south pole, according to NASA. For the first time, the Juno team solicited votes from the public to select all the pictures the JunoCam camera would take during the flyby. Participants on the mission’s web site will
“We’re made of star stuff,” astronomer Carl Sagan famously said. Nuclear reactions that happened in ancient stars generated much of the material that makes up our bodies, our planet and our solar system. When stars explode in violent deaths called supernovae, those newly formed elements escape and spread out in the universe.
NASA has selected two robotic missions to visit asteroids in the early 2020s from a field of proposed interplanetary probes, approving projects to explore a metallic relic from the early solar system and a half-dozen so-called Trojan objects left over from the formation of the outer planets. The Lucy and Psyche spacecraft will join NASA’s line of cost-capped Discovery missions, a program under which the agency’s Mars Pathfinder rover, the Messenger mission to orbit Mercury, and the Dawn probe currently orbiting the dwarf planet Ceres were developed, built and launched. Picked from a slate of 28 proposals submitted to NASA in 2015, Lucy and Psyche will visit worlds never before seen close-up as scientists seek to sort out the violent early history of the solar system, in which proto-planets coalesced from mergers and collisions between rocks and boulders in a disk around the sun. Lucy will launch in October 2021 on a preliminary trajectory to escape the bonds of Earth’s gravity, then return for flybys to use the planet’s gravity to slingshot toward the mission’s targets in the asteroid belt and beyond. The probe’s first destination in April 2025 will be the asteroid DonaldJohanson, named for the paleoanthropologist who discovered
Monster black holes sometimes lurk behind gas and dust, hiding from the gaze of most telescopes. But they give themselves away when material they feed on emits high-energy X-rays that NASA’s NuSTAR mission can detect. That’s how NuSTAR recently identified two gas-enshrouded supermassive black holes, located at the centers of nearby galaxies.
NASA’s Dawn spacecraft has continued its survey of the dwarf planet Ceres this year, discovering rock-bound ice hidden just beneath the airless world’s rugged surface and a handful of icy outcrops inside craters in the northern hemisphere, raising hopes that Ceres could have once held a buried habitable ocean of liquid water.