Mars Orbit Wobble Could Reveal Passing Primordial Black Holes

A new study by MIT physicists suggests that dark matter, a mysterious substance making up about 27% of the universe, could be detected by monitoring the orbit of Mars. Led by David Kaiser and his team, including Sarah Geller and Matt Lehmann, the researchers propose that if a primordial black hole were to pass within a few hundred million miles of Mars, it would cause a slight deviation in the planet’s orbit, detectable by high-precision instruments. This “wobble” could be used to identify the presence of dark matter. The team simulated various asteroid-mass black holes flying through the solar system and found that Mars’ orbit would shift by about a meter within a few years of such an encounter. While confirming the detection would require further work, this innovative approach could provide insight into the elusive nature of dark matter.

In a fascinating study, researchers have proposed a novel way to detect primordial black holes, hypothetical objects that could be remnants of the early universe. By simulating close encounters between these black holes and planets in our solar system, the team has shown that even a brief flyby could leave a subtle signature on the orbits of celestial bodies.

The idea was sparked by a simple calculation performed by physicist Tung, who found that if a primordial black hole were to pass within 1 meter of a person, it would exert a force strong enough to push them 6 meters away in just one second. While the likelihood of such an event is astronomically low, the researchers were intrigued and decided to explore the consequences of a black hole flyby on larger bodies like Earth and the Moon.

Using a simplified simulation of the solar system, the team estimated that a primordial black hole passing close to Earth could cause the Moon’s orbit to wobble slightly. However, they soon realized that other dynamics in the solar system would dampen out this effect. To gain more insight, they generated a more detailed simulation incorporating the orbits and gravitational interactions of multiple planets and moons.

The researchers then calculated the rate at which primordial black holes should pass through the solar system, based on dark matter estimates and the mass of these hypothetical objects. They found that such an event could occur every 10 years or so, with the black hole flying by at velocities of about 150 miles per second.

By simulating various asteroid-mass black holes passing close to Mars, the team discovered that a flyby within a few hundred million miles would cause a detectable wobble in the planet’s orbit. This effect could be measured using high-precision instruments currently monitoring Mars.

While detecting such a wobble would not necessarily confirm the presence of a primordial black hole, it would provide an intriguing clue. To further investigate, the researchers plan to collaborate with experts in simulating large numbers of objects in the solar system, allowing them to inject close encounter scenarios and study their effects with higher precision.

This innovative approach could potentially reveal the existence of primordial black holes, providing a new window into dark matter and the early universe. As Matt Caplan, associate professor of physics at Illinois State University, notes, “It’s a very neat test they’ve proposed… Now that they’ve checked this idea with simulations, they have to do the hard part — checking the real data.”