Stephen Hawking has been gone for three years this month, but he lives on in reruns of “The Big Bang Theory,” “The Simpsons” and “Futurama,” as well as in physics, cosmology and the many other fields his genius influenced. Now he has a chance to be famous in the far reaches of the solar system in a new(ish) but unproven theory that the mysterious Planet Nine exists, but not as a planet. Searching for Hawking radiation, some scientists think they can prove it’s actually a black hole using a high-speed spacecraft flyby. Could proving this convince the cast to reunite for one more “The Big Bang Theory” and toast Stephen Hawking?
“Since this planet has not yet been observationally found with conventional telescope research, it has been argued that it could be a dark compact object, namely a black hole of probably primordial origin. Within this assumption, we discuss the possibility of detecting Planet 9 via a sub-relativistic spacecraft fly-by and the measure of its Hawking radiation in the radio band and conclude that it is too faint compared to the CMB. We thus present other perspectives with rather a satellite mission and conclude that smaller black holes would give much more interesting signals. We emphasize the importance of the study of such Hawking radiation laboratories in the Solar System.”
In a pre-print paper titled “Detecting Planet 9 via Hawking radiation” and another titled “Hawking radiation by spherically-symmetric static black holes for all spins: I -- Teukolsky equations and potentials,” Alexandre Arbey and Jérémy Auffinger from the University of Lyon explain – in detail far beyond this writer’s pay grade – that a planet’s Hawking radiation would be too weak to detect with Earth telescopes but that of small black hole might be unusual enough to be picked up. It could then be inspected by a next generation New Horizons-style spacecraft designed to fly faster and farther. That mission would also help pinpoint its location so that more powerful telescopes could look at it.
“Nevertheless, if P9 were indirectly localized using for example spacecraft trajectory measurements or LSST flares, an orbital mission would be of great importance to study the properties of black holes and Hawking radiation, and would allow for more advanced measurement techniques, for example by screening the CMB and focusing the antenna on P9. Finally, we extrapolated the present discussion to lighter PBHs that could have been captured by the gravitational field of the Sun and concluded on the advantages of these configurations for the detection of Hawking radiation, since their emissivity would be dominant as compared to the CMB.”
In essence, Black Hole 9 would be the closest black hole to Earth, thus making black hole research much easier to accomplish. This would help all astronomers by providing more data on how to better search the Cosmic Microwave Background for the anomalies that indicate black holes and more. Finally, it would open the door to the possibility that the Sun has more primordial black holes in its grasp than just Black Hole/Planet 9.
If Hawking radiation really proves that Planet 9 is actually Black Hole 9, what would Stephen Hawking say? Not sure about that, but there’s a good chance that if he reads this “way out of my league” review, he’d says something like he did to another poor soul on “The Big Bang Theory”:
“You made an arithmetic mistake on page 2. It was quite a boner.”