Our solar system might be chock-full of tiny black holes, with some tracing out beautiful patterns resembling Spirograph drawings as they orbit inside the sun.
Invisible dark matter seems to account for the vast majority of mass in the universe, but scientists don鈥檛 know what exactly it is. Hypothetical black holes that formed shortly after the big bang, called primordial black holes, are one dark matter candidate. If they do exist, our solar system should be full of them.
at the Massachusetts Institute of Technology and his colleagues simulated what the orbits of tiny black holes around 鈥� and within 鈥� the sun or a similar star might look like.
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For primordial black holes to account for the effects of dark matter, each must have a mass between 100 billion and 100 million billion tonnes. 鈥淚t鈥檚 a mass typical of asteroids in our solar system, big hulking space rocks, but to make these things into black holes you have to squeeze that mass into an exquisitely small size, the size of an atom or even smaller,鈥� says Kaiser.
Because the sun is the most massive object in our solar system, it would probably capture some of these black holes. The tiny black holes, each moving at hundreds of kilometres per second, could then make hundreds of orbits through the sun before they actually collide with any significant amount of matter. 鈥淭hey鈥檙e sort of going about their business without a care in the world,鈥� says Kaiser.
In fact, it would take millions to billions of years for friction to drag a primordial black hole into the centre of the sun. And in the meantime, Kaiser and his colleagues鈥� research suggests they could occupy a stunning array of possible orbits inside the sun, from closed trajectories that simply trace out a near-perfect circle to more elaborate patterns聽(see picture above).
We will never be able to observe primordial black holes inside the sun. But if they do lurk elsewhere in the solar system, we may be able to spot the effects they have on other objects. 鈥淚f you put the mass of an asteroid on a trajectory through our solar system, it鈥檚 going to set other things wobbling,鈥� says Kaiser. 鈥淣ot by a lot. If you see particular motions, then that could be a signature of one of these objects buzzing through the inner solar system.鈥�
arXiv
