One example of this is the aptly named process of “spagetization,” which is often illustrated by the tale of an astronaut who ventured a lot near the event horizon of a black hole – the point from which light cannot escape – and fell upside down. Although her head and feet were a few meters apart from each other, the difference in the gravitational forces acting on them would be very large, and it would stretch like spaghetti.
Interestingly, the more dramatic the effect, the smaller the black hole. Schultz explains that it’s all about relative distances – if you are two meters tall, and you fall across an event horizon about one meter from the center of a primitive black hole, the discrepancy between your head and feet position is greater, compared to the size of the black hole. This means that you will extend much more than if you fell into a stellar a million miles wide.
“Oddly enough, it’s more interesting,” says Schultz. Spaghettiver has already been seen through the telescope, when a star came very close to a stellar black hole at a distance of 215 million light-years from Earth. Torn to pieces (No astronauts were injured.) But if there was a primordial black hole in our solar system, it would provide astrophysicists the opportunity to study this behavior – and many others – closely.
So what makes Batygin see the possibility that the long-awaited Planet Nine could be a black hole instead? “It is an innovative idea, and we cannot restrict its formation even in the slightest part,” he says. “I think maybe this is just my bias, being a professor of planetary sciences, but planets are more common …”
While Unwin and Schultz are rooting a primitive black hole for his experiment, Batygin is totally keen on having a giant planet – citing the fact that the most common type throughout the galaxy is one that has roughly the same mass as Planet Nine.
“Meanwhile, most of the exoplanets orbiting around sun-like stars lie in this strange range because they are larger than Earth and much smaller than Neptune and Uranus,” he says. If scientists find the missing planet, it will be the closest they can get to it from a window to those found elsewhere in the galaxy.
Only time will tell if the last mission will be more successful than Lowell’s. But Batygin is confident that their missions are completely different. “All of the proposals are quite distinct in both the data they seem to seek to explain, as well as the mechanisms they use to explain it,” he says.
Either way, the search for the already legendary Ninth Planet helped transform our understanding of the Solar System. Who knows what else we’ll find before the hunt ends.
Zaria Gurvit is a prominent journalist for BBC Future and Twitter Embed a Tweet
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