The effect of a primordial black hole hitting the Sun ought to be easily observable, say physicists at New York University and Princeton University.

Such an event wouldn’t be as catastrophic as it sounds, they suggest. The likelihood is that a primordial black hole with mass of an asteroid or comet would pass straight through the Sun, generating a small puff of X-rays in the process.

However, such a burst would be less even than the background rate of X-rays, so it would be impossible for astronomers to see. Instead, the collision would generate supersonic turbulence that would set the Sun ringing like a bell.

They say they are able to calculate what these oscillations would look like. They ought to be visible with today’s solar observatories as a kind of solar hiccup, so we might have seen them already.

Ref.: Michael Kesden, Shravan Hanasoge, Transient solar oscillations driven by primordial black holes, arXiv.org, May 31, 2011 [arXiv:1106.0011v1]