Researchers say space atomic clocks could help uncover the nature of dark matter

Learning an atomic clock on-board a spacecraft contained in the orbit of Mercury and really close to to the sun may be the trick to uncovering the character of dark matter, suggests a brand new examine revealed in Nature Astronomy.

Darkish matter makes up greater than 80% of mass within the universe, however it has thus far evaded detection on Earth, regardless of a long time of experimental efforts. A key element of those searches is an assumption in regards to the native density of dark matter, which determines the variety of dark matter particles passing via the detector at any given time, and subsequently the experimental sensitivity.

In some fashions, this density may be a lot larger than is normally assumed, and dark matter can turn out to be extra concentrated in some areas in comparison with others.

One necessary class of experimental searches are these utilizing atoms or nuclei, as a result of these have achieved unbelievable sensitivity to alerts of dark matter. That is doable, partly, as a result of when dark matter particles have very small plenty, they induce oscillations within the very constants of nature. These oscillations, for instance within the mass of the electron or the interplay energy of the electromagnetic pressure, modify the transition energies of atoms and nucleii in predictable methods.

A global group of researchers, Kavli Institute for the Physics and Arithmetic of the Universe (Kavli IPMU) Mission Researcher Joshua Eby, College of California, Irvine, Postdoctoral Fellow Yu-Dai Tsai, and College of Delaware Professor Marianna S. Safronova, noticed potential in these oscillating alerts. They claimed that in a specific area of the solar system, between the orbit of Mercury and the sun, the density of dark matter could also be exceedingly massive, which might imply distinctive sensitivity to the oscillating alerts.

These alerts might be picked up by atomic clocks, which function by fastidiously measuring the frequency of photons emitted in transitions of various states in atoms. Ultralight dark matter within the neighborhood of the clock experiment may modify these frequencies, because the oscillations of the dark matter barely improve and reduce the photon power.

“The extra dark matter there’s across the experiment, the bigger these oscillations are, so the native density of dark matter issues lots when analyzing the sign,” mentioned Eby.

Whereas the exact density of the dark matter close to the sun just isn’t well-known, the researchers argue that even a comparatively low-sensitivity search may present necessary data.

The density of dark matter is just constrained within the solar system by details about planet orbits. Within the area between the sun and Mercury, the planet nearest to the sun, there’s virtually no constraint. So a measurement onboard a spacecraft may rapidly uncover world-leading limits on darkish matter in these fashions.

The know-how to place their principle to the take a look at already exists. Eby says the NASA Parker Photo voltaic Probe, which has been working since 2018 with the assistance of defending, has traveled nearer to the sun than any human-made craft in historical past, and is at present working contained in the orbit of Mercury, with plans to maneuver even nearer to the sun inside a 12 months.

Atomic clocks in space are already well-motivated for a lot of causes apart from trying to find dark matter.

“Lengthy-distance space missions, together with doable future missions to Mars, would require distinctive timekeeping as could be offered by atomic clocks in space. A doable future mission, with shielding and trajectory similar to the Parker Photo voltaic Probe, however carrying an atomic clock equipment, might be enough to hold out the search,” mentioned Eby.

Particulars of their examine had been revealed in Nature Astronomy.