Black holes are regions of space where gravity is so extreme that nothing, not even light—the fastest thing in the universe—can escape.
But is there a possibility that planet Earth will one day be pulled into a black hole? And if so, what would happen in this scenario?
What is the probability that the Earth will be consumed by a black hole?
Experts who spoke with news week said there is practically zero chance of Earth ever colliding with a black hole before being swallowed by the sun in about five billion years.
“For starters, the space is aptly named,” Doug Gobielle, a professor in the University of Rhode Island’s physics department, told news week† “The overall average density of the universe’s luminous matter is about one proton per cubic meter. In the Milky Way and the Solar System, this density is considerably higher, but still almost non-existent.”
“Objects that we consider ‘large’ and ‘dense’ are quite rare in the grand scheme of the universe, namely planets, stars and the associated stellar remnants that leave stars behind, including white dwarfs, neutron stars and black holes,” said Gobielle.
Although there are countless stars in our galaxy alone, random encounters between them are extremely rare because of the immense space between the objects, Jonathan Zrake, an assistant professor of physics and astronomy at Clemson University, told me. news week†
“Aside from a hyper-advanced civilization with nearly unlimited resources and energy that would purposefully ‘launch’ a black hole into the solar system, such an encounter is so unlikely that it will be close to zero,” Gobielle said.
“Just as we generally don’t worry about stars passing through the solar system, this can be extended to all objects in the galaxy,” he said.
Stars occasionally wander close enough to chase a few comets from the farthest outer reaches of the solar system called the Oort cloud, but this is the magnitude of their gravitational impact on the solar system and it would probably be the same for any black holes or other compact masses that happen to wander around the solar system.”
Do ‘near’ black holes pose a threat?
According to experts, the closest black holes to our solar system are far too far away to have any effect on our solar system.
For example, V616 Monocerotis (V616 Mon), believed to be one of the closest black holes to our solar system, is more than 3,000 light-years away.
“Even if the black hole were to consume its binary partner, there just wouldn’t be enough mass to do anything extraordinary except produce a few bursts of radiation,” Gobielle said. “At a distance from Earth, we would only notice this by looking directly into the system with powerful observation tools. The impact on Earth would be zero.”
Black holes come in two main classes: stellar and supermassive (although recent research has suggested there is likely an intermediate class as well). Stellar black holes tend to have masses several times larger than our Sun. Supermassive black holes, on the other hand, can have masses from millions to billions of solar masses.
Stellar-mass black holes, such as V616 Mon, are the remnants of massive stars that die in catastrophic cosmic explosions known as supernovas. A nearby star that could in principle form a black hole is Betelgeuse, the second-brightest star in the constellation Orion.
According to Zrake, Betelgeuse is nearing the end of its life and will likely produce a supernova sometime in the next 10,000 years. But this star is about 500 light-years away, and if it produces a black hole, there would be no impact on Earth.
How close would we have to get to a black hole to have an impact?
While it would be challenging to miss a supermassive black hole, or even a medium-mass black hole anywhere near the Solar System, a stellar-mass black hole that is wandering close to the Solar System without us realizing it early on is. brands, within the realm of possibility. said Gobielle.
†[But] even a large black hole with stellar masses, say 30 solar masses, would have to be closer than Neptune (about 30 times the Earth-Sun distance) to get gravitational effects on Earth, and about the distance from Jupiter (about five times the Earth-Sun distance). sun) the Earth-Sun distance) to pull on Earth with about the same gravity as the Sun’s gravity on Earth,” he said.
Black holes have a reputation for being almighty cosmic vacuum cleaners that swallow everything in their path, but the reality, according to Gobielle, is somewhat different.
“Black holes are generally bad at consuming matter,” he said. “The general litmus test for this is to see why the universe has not been consumed by black holes. The answer is that under most conditions black holes are very inefficient at consuming matter and growing to larger sizes.”
What if the Earth were sucked into a black hole?
If a black hole somehow got extremely close to Earth (closer than the Moon’s orbit, for example) and traveled slowly enough, our planet would likely be ripped apart by the extreme gravity of the object.
“The atmosphere and oceans would be stripped from the Earth’s surface and molten metal would flow from Earth’s mantle into space,” Zrake said.
This terrestrial debris would orbit the black hole and vaporize into ionized gas — that is, a gas made up of atoms or molecules that have lost or gained electrons. The gas would form a ring of material around the black hole, known as an accretion disk, and most of it would be consumed over the course of several hours to days, Zrake said.
“Energy released from the collapsing gas would drive powerful plasma winds” [one of the four fundamental states of matter consisting of charged particles] into space and produce high-energy radiation. That light can likely be detected as a brief flash of hard X-rays by nearby alien astronomers,” he said.
But the odds of this scenario happening are astronomically low. Slightly more plausible, but still incredibly unlikely, is a scenario where a black hole came close enough to impact Earth, though not close enough to consume our planet.
The biggest danger here, at least to life, would be the black hole that disrupts Earth’s orbit enough to affect climate, or potentially dislodge massive amounts of debris in the solar system (such as asteroids, comets, and moons) and collide. places naturally with our planet, according to Zrak.
“While life on Earth could probably survive such an event, humanity and almost all multicellular species on Earth almost certainly wouldn’t,” Gobielle said.