Black holes are one of the most frightening phenomena that exist in space. Their gravitational force is so strong that they distort space and time beyond possible limits.

Therefore, it begs a question what could happen if such a monster suddenly appeared close to our solar system?

Before answering this question, let us first clarify some other questions. At what distance would it appear? Where would it come from? How massive would such a black hole be?

## The possibility of encountering a black hole

Let’s begin by pointing out that our Sun is not capable of becoming a black hole since the gravitational collapse of a star requires it to be 10-15 times more massive. There are no such stars in our galaxy, nor expected to be discovered. The closest to us are red dwarfs, each weighing around 8-60% of the sun’s mass.

So we are left with only two possibilities. The first one suggests that a black hole appears spontaneously in the vicinity of Earth. This threat is minimal.

But the second possibility is more real. In 2000, astrophysicists suggested the existence of black holes traveling through the universe. But still, the probability of one of them passing by our solar system is tiny. But it is still worth exploring.

## How black holes distort space and time

At a great distance, a black hole behaves like an ordinary object with a large mass, i.e. it obeys the laws of classical mechanics as well as Newton’s law of universal gravitation. In fact, it is impossible to distinguish between a blue dwarf weighing 265 suns from a black hole of the same mass based on their behavior.

But when we get closer to the dark monster, the laws of Einstein’s general relativity theory come into play, according to which the gravitational force is capable of distorting space and time, especially if we are dealing with a black hole.

When approaching the massive monster in a spaceship, we will notice that the closer we get to the black hole, the greater effort the engines of the ship will have to exert while trying to stay on a circular orbit.

A point will come when nothing can keep the steady spiral plunge into the event horizon of the black hole. Not even the light can escape from there.

You will find yourself inside a black hole heading toward singularity into the core of infinitely distorted space and time, in which known laws of physics cease to exist.

While approaching the dark monster, the time starts to slow down. For you, however, nothing will change, but for the observers on the outside, the time around your ship will start to flow like syrup.

When you approach the event horizon, it will look from the outside as if you were frozen and motionless. Since the light cannot escape a black hole, it will be the last thing others will know about your existence.

## How would we know if a black hole was approaching?

Imagine that the unthinkable has happened. A massive black hole outside our galaxy approached a newly-exploded supernova, which pushed the giant at speeds of several hundred kilometers per second towards our galaxy.

There is no way of knowing. At least unless the black hole begins to interact with a visible object since not even the light is able to break free out of its “bowels”.

So instead of looking for black hair on the dark carpet, let’s think about how to determine if the giant is approaching us using indirect ways.

First, the matter which has been affected by the black hole emits streams of particles that can reach us.

Secondly, the distortion of space surrounding a black hole can be detected by earthlings. The gravitational lens predicted by Einstein’s theory of relativity was repeatedly noted by astronomers near massive objects such as galaxies, black holes, or our sun.

And yet, even under ideal circumstances, it would be difficult to notice the dark monster approaching. In order for astronomers to detect a change in the radiation of the star, a black hole must pass exactly between the star and us, actually crossing its rays. But even in this case, we would need a lot of luck to notice this effect.

Finally, a black hole can have a gravitational effect on celestial objects: planets, stars, asteroids, and comets. Thus, we come to the original question: how far from the solar system would our hypothetical black star pass by?

## The ‘judgment day’

Clearly, the closer the black hole is, the worse the outcome is for us. Imagine a sparrow flying through a spider web between the branches of trees. The close proximity to this monstrous black hole could alter planetary orbit or cause distortion of the entire solar system.

If the gravity exerted by the black hole changed our orbit around the sun to be closer, or, alternatively took it further away from it, there would be a possibility of catastrophic climate changes, tsunamis, typhoons, and earthquakes of an unprecedented magnitude.

In the worst case, the passing of a black hole in close proximity to us can launch us right in the scorching center of the sun, or knock us out of the solar system into the coldness of space.

As once the famous astrophysicist Neil Degrassi Tyson put in perspective,

The day when a black hole ‘decides’ to pay a visit to our solar system will turn out to be a very disappointing experience“.

## Journey inside a black hole

Let us now imagine that our visitor was not just a black hole but a super-massive monster with an event horizon of more than five times bigger than our entire solar system. Naturally, such a giant could swallow us up with the sun and the planets just like a white shark can swallow an unfortunate tuna fish.

But will we be able to at least look inside the dark monster? Let’s suppose that we have created a kind of protective shield that protects the planet from any outside threats, including the monstrous gravity measured in millions of G’s. Earth would make its way down the spiral orbit towards the event horizon of an unwanted visitor.

In case if a giant black hole with a mass of five million suns appeared right in the center of our galaxy, we would have about 16 seconds to get down after crossing the event horizon, until we reach the singularity point.

During this travel, we would be able to see the stars because their light penetrates inside black holes, but distorted space and time would change them beyond recognition. It would seem to us as if we were looking through some kind of an unimaginable kaleidoscope.

Near the singularity point, the entire universe around us would shrink into a thin strip of glowing blue light, and then the remnants of what once was Earth would enter into a state of infinite distortion.

### This Post Has 3 Comments

1. Robert Fournier

“…10 to 15 times more massive. There are no stars in our galaxy”

Are you serious?! There are many. VY Canis Majoris (30 solar masses) is less than 5 thousand LY away, which is not only in our galaxy but in our region go the galaxy.

2. tmraywood

Here, the devil’s not in the details so much as in the question itself. The cosmos is known to be expanding spherically, that is, from its center outward. Most recent measurements support that there’s no apparent limit to that expansion. If the expansion were slowing for the outermost regions then, yes, this would suggest of a limit. Instead, surprisingly, the pace appears to be picking up.

There are two important things we can ‘soft extrapolate’ from this. One is that rates of expansion, though variant, are uniform at the local level. The other is that rates of expansion are gradually less toward the cosmic center. The first means that no matter what shell or neighborhood a region occupies, everything else in that shell is moving away from the cosmic center at the same rate. If that rate increases, as it appears to have done for the outermost region, then it increases equally for everything in that shell. The second means that none of the contents of any ‘more inner’ shell are expanding at a rate equal to or greater than [that of] the contents of any ‘more outer’ one.

These measurements do not speak to ‘lateral’ movement within a given shell. (We’ll get to that.) But in terms of large scale, shell-to-shell movement it allows of a couple hard conclusions. Any black hole ‘beyond’ us, we cannot catch. And any black hole ‘behind’ us, cannot catch us. (By ‘behind us’ and ‘beyond us’, respectively, it is simply meant ‘nearer to the cosmic center than we’ are or ‘farther from the cosmic center than we are’.) In either case, no black holes outside our neighborhood can possibly approach us or be approached by us.

So far I’ve spoken primarily to what may or may not occur BETWEEN cosmic neighborhoods. But for what possibly occurs IN a given neighborhood, there too there are very real limits. For starters, matter completely on the other side of the cosmos can still be in our neighborhood so long as its distance from the cosmic center is roughly the same as our own and, that is, its rate of expansion away from center matches ours. But to think the interplay of matter and energy that far away might have any but the most trace effects on our region is fully unrealistic. So really, reasonably, what we’re specifically limiting our considerations to is what, while IN our neighborhood, is also reasonably PROXIMATE to the space we occupy. And while this comparatively speaking is what I meant earlier when I spoke of ‘lateral’ movement, this was not to suggest action on either a fixed line or a fixed plane. So granted some meaningful proximity to ‘another’ system, the interplay of matter and energy between ‘it’ and ‘us’ is to be expected. For example, while both ‘it’ and ‘we’ can be fleeing the cosmic center at the same rate, there’s nothing preventing our two systems from gradually moving closer to each other. In fact, many models plainly predict this. But remember, on balance whatever’s drawing us is also ‘being drawn’. So these models are tenuous at best. What remains more likely is what we see [already] in place, to wit a state of relative equilibrium. It’s not just that the cosmos is far too vast and far too active for any single event to have much of an effect on all else, it’s that even a given region of a given neighborhood is far too vast and far too active for any single event to have much of an effect on all else in the region of that neighborhood. So while, sure, black holes are definitely the creepy spiders of the cosmos, as events go they’re of truly no consequence granted what we know of how we’re situated. Whether extant or to be formed, (a well understood process), they’re well off page.

3. harley