Meteorite radars can guide us to dark matter


Meteorites may help astronomers devise a new way to locate dark matter: mysterious, invisible particles hitherto only discerned by their effect on the cosmos.

Five times more frequent than ordinary matter, dark matter makes up about 85% of the total mass of the universe and about a quarter (26.8%) of the total mass and energy of the universe. Humans can’t detect these elusive particles directly, since dark matter doesn’t emit light, so scientists use telescopes like Hubble to observe their influence on galaxies and other distant star clusters.

Now, according to a study led by researchers at the Ohio State University, ground-based radar systems could be used to aid in the search.

Study co-author John Beacom, a professor of physics and astronomy at Ohio State, said that while scientists typically look only for tiny dark matter particles with small masses, the goal of this new research is improve the search by helping to characterize macroscopic dark matter: Particles with a large mass that might not reach traditional ground-based detectors.

“One of the reasons dark matter is so hard to detect could be because the particles are so massive,” Beacom said. it’s a statement. “If the dark matter mass is small, then the particles are common, but if the mass is large, the particles are rare.”

Although these particles cannot be touched or seen, dark matter can be perceived by its gravitational effects on other celestial phenomena, such as stars or black holes.

While its effects on other natural systems aren’t easy to categorize, taking the time to learn more about dark matter opens up new avenues for scientists to understand the size, shape and future of the cosmos, Beacom said. Such detections can also reveal the mass of these particles, which, depending on their size, can have huge effects on galaxy formation and structure.

The research has been published in the online repository arXiv.

What makes the research so novel is that the scientists applied the same technology used to track meteorites as they streak across the sky. As they pass through Earth’s atmosphere, both meteors and dark matter particles produce deposits of ionization, a form of radiation that leaves behind free electrons, atoms capable of conducting electricity. The electromagnetic waves released by the radar bounce off free electrons, indicating the presence of otherworldly matter, which can then be used to distinguish dark matter from meteorites. In this way, the entire atmosphere of the planet can be transformed into an efficient large-scale particle detector.

Although scientists have used this method of hunting meteorites for decades, Beacom said he was surprised no one had ever applied these systems, or their previously collected data, in the search for dark matter.

One of the most significant conclusions of the study is how the team’s new method could complement other cosmological searches for dark matter, as their system offers a level of precision and sensitivity that many other techniques lack.

“Current cosmology techniques are quite sensitive, but they have no way of verifying their own work,” Beacom said. “This is a totally new technique, so if scientists aren’t sure what they’ve detected, a signal from cosmology could be verified in detail with the radar technique.”