Interstellar Mission to a Black Hole

Summary

We normally think of interstellar flight in terms of reaching a single target. The usual destination is one of the Alpha Centauri stars, and because we know of a terrestrial-mass planet there, Proxima Centauri emerges as the best candidate. I don’t recall Proxima ever being named as the destination Breakthrough Starshot officially had in mind, but there is such a distance between it (4.2 light years) and the next target, Barnard’s Star at some 5.96 light years, that it seems evident we will give the nod to Proxima. If, that is, we decide to go interstellar. Let’s not forget, though, that if we build a beaming infrastructure either on Earth or in space that can accelerate a sail to a significant percentage of lightspeed, we can use it again and again. That means many possible targets. I like the idea of exploring other possibilities, which is why Cosimo Bambi’s ideas on black holes interest me. Associated with Fudan University in Shanghai as well as New Uzbekistan University in Tashkent, Bambi has been thinking about the proliferation of black holes in the galaxy, and the nearest one to us. I’ve been pondering his notions ever since reading about them last August. Black holes are obviously hard to find as we scale down to solar mass objects, and right now the closest one to us is GAIA-BH1, some 1560 light years out. But reading Bambi’s most recent paper, I see that one estimate of the number of stellar mass black holes in our galaxy is 1.4 X 109. Bambi uses this number, but as we might expect, estimates vary widely, from 10 million to 1 billion. These numbers are extrapolated from the population of massive stars and to a very limited extent on clues from observational astronomy. Image: The first image of Sagittarius A*, or Sgr A*, the supermassive black hole at the center of our galaxy. Given how hard it was to achieve this image, can we find ways to locate far smaller solar-mass black holes, and possibly send a mission to one? Credit: Event Horizon Telescope Collabo...