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
Thursday 12 January brings not only a full Moon, but also finds brightest planet Venus at its greatest easterly elongation from the Sun. By the time darkness falls in Western Europe and the UK, Venus also lies just 0.4 degrees from outermost planet Neptune, while Mars lies less than the span of a fist at arm’s length to their upper left.
Searching for planets around other stars is a tricky business. They’re so small and faint that it’s hard to spot them. But a possible planet in a nearby stellar system may be betraying its presence in a unique way: by a shadow that is sweeping across the face of a vast pancake-shaped gas-and-dust disk surrounding a young star.
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.
It’s time to direct your attention skyward for some celestial pyrotechnics from the first major annual meteor shower — the Quadrantids. The short-lived peak of this active shower is predicted to occur at 2pm GMT on 3 January, favouring observers in the west of North America, but most Northern Hemisphere observers with clear skies will still see some shooting stars.