Studying an atomic clock on-board a spacecraft inside the orbit of Mercury and very near to the sun might be the trick to uncovering the nature of dark matter, suggests a new study published in Nature Astronomy.

Dark matter makes up more than 80% of mass in the universe, but it has so far evaded detection on Earth, despite decades of experimental efforts. A key component of these searches is an assumption about the local density of dark matter, which determines the number of dark matter particles passing through the detector at any given time, and therefore the experimental sensitivity.

In some models, this density can be much higher than is usually assumed, and dark matter can become more concentrated in some regions compared to others.

One important class of experimental searches are those using atoms or nuclei, because these have achieved incredible sensitivity to signals of dark matter.

NASA delivered the first flight hardware for the Lunar Pathfinder mission to ESA (European Space Agency), which formally accepted the instrument on Nov. 4. NASA's Goddard Space Flight Center in Greenbelt, Maryland, developed the instrument, a laser retroreflector array, which will test new navigation techniques for lunar missions.

NASA and ESA plan to launch Lunar Pathfinder via a future Commercial Lunar Payload Services delivery. In addition to testing navigation capabilities, Lunar Pathfinder will operate as a commercial communications relay satellite and provide communications services for exploration missions on the lunar surface.

The Lunar Pathfinder mission is led by Surrey Satellite Technology Ltd (SSTL), and ESA arranged for the mission to provide communications services to NASA. Teams from NASA, ESA, and SSTL completed inspections when the laser retroreflector array arrived at SSTL's facility in Guildford, U.K., where it will be installed in the satellite.

NASA's Orion capsule and its test dummies swooped one last time around the moon Monday, flying over a couple Apollo landing sites before heading home.

Future planetary missions could explore in extremely cold temperatures that stymie existing spacecraft, thanks to a project under development at JPL.

When NASA returns to the moon with Artemis, the agency and its partners will reach unexplored regions of the lunar surface around the South Pole, where it can get much colder at night than even on frigid Mars.