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

Finding out an atomic clock on-board a spacecraft contained in the orbit of Mercury and really close to to the sun could 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, but it surely has to this point evaded detection on Earth, regardless of a long time of experimental efforts. A key element of those searches is an assumption concerning the native density of dark matter, which determines the variety of dark matter particles passing by the detector at any given time, and subsequently the experimental sensitivity.

In some fashions, this density could be a lot increased than is often assumed, and dark matter can grow to be extra concentrated in some areas in comparison with others.

One essential 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, partially, 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 power, modify the transition energies of atoms and nucleii in predictable methods.

A global crew 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 selected 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 essential info.

The density of dark matter is simply 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 concept to the check already exists. Eby says the NASA Parker Photo voltaic Probe, which has been working since 2018 with the assistance of protecting, 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 yr.

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

“Lengthy-distance space missions, together with doable future missions to Mars, would require distinctive timekeeping as can be supplied 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 adequate to hold out the search,” mentioned Eby.

Particulars of their examine had been revealed in Nature Astronomy.