Is there a 5th force? Asteroid Bennu's data suggests so
Asteroid Bennu, a near-Earth object, has played a key role in improving our knowledge of asteroids and Earth's history. Now, a new study of Bennu's tracking data indicates it could also shed light on a possible fifth fundamental force in the universe. This hypothetical force would join gravity, electromagnetism, and the strong and weak nuclear interactions as part of our Standard Model of Physics.
Hypothetical particles and dark matter
The proposed fifth force could be transmitted by hypothetical ultralight particles, a proposed type of dark matter that has not yet been directly detected. The international team behind the study utilized data from the OSIRIS-REx spacecraft, which visited Bennu between 2018 and 2021, as well as measurements taken from Earth. This information helped determine how massive these potential particles would need to be if they existed at all.
Bennu's data could reshape our understanding of Physics
Astrophysicist Yu-Dai Tsai, from the Los Alamos National Laboratory in New Mexico, said that interpreting the data from tracking Bennu could improve our understanding of the theoretical foundations of the universe. This could revolutionize our knowledge of the Standard Model of Physics, gravity, and dark matter. The detailed information captured through long-term tracking of Bennu's orbit around the Sun may reveal extremely subtle effects of hypothetical forces too elusive to measure until now.
String theory and Yukawa interaction
A force derived from string theory has been proposed to tweak gravity on large scales, possibly resulting in particles that could be perfect candidates for dark matter. These particles would behave according to a Yukawa interaction, meaning a new kind of field may affect orbits of large objects over long distances with subtle tweaks to Newton's laws on gravity.
Bennu's path and the 5th force
In their research, scientists found that standard Physics could adequately explain Bennu's path. Now, this finding doesn't entirely dismiss the possibility of a fifth force, but it does suggest that if such a force exists, its strength or range will be below a certain level. "The tight constraints we've achieved translate readily to some of the tightest-ever limits on Yukawa-type fifth forces," said cosmologist Sunny Vagnozzi from the University of Trento in Italy.
