Since its discovery 25 years ago, a near-Earth asteroid named Bennu has significantly contributed to our understanding of asteroids, as well as the history of our planet and, potentially, the fundamental forces of the cosmos. A recent study that saw samples being collected from Bennu strongly hints at the existence of a fifth force in the universe. As such, it’s making waves in the physics field.
Bennu’s role in exploring the fifth force
Bennu has been meticulously monitored by astrophysicists since its discovery in 1999. It has been providing a wealth of data that enriches our understanding of asteroid behavior, as well as Earth’s early history.
Additionally, Bennu has given strength to the concept of the fifth fundamental force of nature. In the context of physics, the fifth force typically refers to a hypothetical fundamental force that exists beyond the four known fundamental forces: gravity, electromagnetism, and strong and weak nuclear interactions.
The concept of an invisible fifth force influencing celestial bodies is akin to watching pool balls behave in unexpected ways due to a tilt in the table. In a similar way, it could explain the peculiar orbits and movements of planets, moons, and other celestial objects that appear to contradict the predictions made by standard physics.
Team discovers unexpected influences on asteroid’s trajectory
Astrophysicist Yu-Dai Tsai from the Los Alamos National Laboratory in New Mexico spearheads an international research team that explores this concept. By utilizing Bennu’s tracking data, coupled with ground-based measurements, they placed tight constraints on the characteristics of potential new particles that could govern this hypothetical force.
Carefully analyzing this data acquired by the OSIRIS-REx spacecraft that visited Bennu from 2018 to 2021, the team deduced in their study the potential influences of previously undetectable forces on the asteroid’s trajectory. This study specifically centers on Yukawa interactions, which suggests that newly proposed particles might subtly alter gravitation effects over large distances.
While the analysis shows that standard physics could explain Bennu’s path effectively, it did not entirely rule out the possibility of a fifth force, either.
“The tight constraints we’ve achieved translate readily to some of the tightest-ever limits on Yukawa-type fifth forces,” said study co-author Sunny Vagnozzi. “These results highlight the potential for asteroid tracking as a valuable tool in the search for ultralight bosons, dark matter, and several well-motivated extensions of the Standard Model.”
Fifth force: A new frontier in astrophysics
Overall, the recent findings of this study suggest the fifth fundamental force of nature, whose effects are currently too subtle to detect but could still “add to our understanding of the theoretical underpinnings of the universe,” says Tsai.
By harnessing space quantum technologies and through dedicated space missions, the team is poised to improve measurement accuracy, thus bringing us closer to discovering the particles that could define a fifth force.
They also emphasized the importance of asteroid tracking in uncovering new physics. Historical examples, such as the prediction of Neptune’s existence based on Uranus’ orbital irregularities, illustrate how identifying these anomalies can lead to major breakthroughs.
Tsai and his team are now focusing on other near-Earth objects as key targets for investigating fifth-force physics. Specifically, they will focus on Apophis, an asteroid set to approach Earth in 2029. NASA’s OSIRIS-APEX spacecraft will gather data on Apophis’ path, providing precise measurements that may shed light on this elusive fifth force.
Regardless of its existence, the team’s research on the fifth force could reshape our very understanding of physics. Resultantly, it opens up possibilities for exploring other celestial bodies. Indeed, the quest for this mysterious force may yield fresh insights into the universe’s nature.