The effect of a black hole passing by our solar system

The effect of a black hole passing by our solar system

When we discussing about astronomy, there are lots of interesting questions which reflects our interests about the universe, come out from the creative mind of science fiction fans. One of them is about what happen to our solar system if a black hole enter and pass by our solar system. Of course the answer depends on how big the black hole is, and where on the solar system plane, the black hole passes by.

Here I will show the result of my experiment, not using actual stars, planets and black holes, of course, as you can believe me, I am not strong enough to throw a black hole to a solar system, and I am not rich enough to have more than one solar system at my disposal. NCGS is a good tool to use if we want to do some experiments, inexpensive compared to using real solar system and black hole.

As the NCGS that I use doesn’t take relativistic effect into account, I will use black holes, moving at 3E7 m/s or 0.1 c (so the relativistic effect can be neglected), to bombard a model resembling our solar system.


First Case - 100 Solar Mass Black Hole, Opposing Side

The first case here is the one where a 100 Solar Mass black hole is closing by from a place 2E12 m ( 13.333 AU )above the solar system plane, with speed of 3E7 m/s ( 0.1c ). The black hole will spend about two days inside the 2E12 m sphere with sun at the center, and intersect the solar system plane, 189,590,000 km ( 1.2639 AU ) away from the Sun, and 339,590,000 km away from Earth. (click image for more detail)

The result is that the black hole only gives Sun and any other planets inside the solar system, some acceleration, then leave it alone. The Sun is accelerated, along with other planets, but the planets still orbit the Sun as if nothing had happened. This is because the tidal force of the black hole is not enough to break the formation of the solar system.


Second Case - 1000 Solar Mass Black Hole

So the next we will use a bigger black hole, with 1000 Solar Mass. The black hole is closing by from a place 4.8E12 m ( 32 AU ) above the solar system plane, with speed of 3E7 m/s ( 0.1c ). The black hole will spend about two days inside the 2E12 m sphere with sun at the center, and intersect the solar system plane, 189,590,000 km ( 1.2639 AU ) away from the Sun, and 245,262,110 km away from Earth. (click image for more detail)

Now, the black hole disrupts the orbit of Venus, Mars and Earth and throws them out of our Solar System. Mercury, which lies in the innermost orbit, doesn’t suffer as much as other planet, as the energy of the black hole isn’t enough to throw it out of orbit, but now mercury have an orbit with greater eccentricity.


Third Case - 1000 Solar Mass Black Hole

In the previous experiment, the black hole pass the solar system plane, in the middle of the first and second quadrant, in this experiment will pass the solar system plane, in the middle of the third and fourth quadrant, where all planets are headings to. Now, what will happen if a 1000 Solar Mass black hole intersect the solar system plane, 189,590,000 km ( 1.2639 AU ) away from the Sun, and 234,095,984 km away from Earth. (click image for detail)


Surprisingly, the black hole didn’t do as much damage as if the black hole intersects the solar system plane in the other side. Now Mercury, Venus, Earth and Mars have an orbit with higher eccentricity, but none of them escape the solar system.


Fourth Case - Two 1000 Solar Mass Black Hole

Now, lets consider what happen if something like two 1000 Solar Mass black holes pass our beloved astronomical backyard. See the data inside the image for more information, as the condition involved is a bit complicated. (The two white trail is the path of the black hole)

As we can see, now both Earth and Mars are slingshoted away from the solar system. Some outer planets in other hand are closing to the sun. We can see the orbit of Jupiter, Saturn and Uranus, inside the 1E12 m radius from the sun. If big planets are closing by the Sun, then it is also likely that objects like the asteroid belt will also come to the inner part of the solar system, putting the inner planet ( if they are still inner planet ) into the danger of meteor shower. But the giant planets closing by have some probability to offer some protection from this catastrophe.

Black hole passing a planetary system doesn’t always seems to bring too much trouble if the black hole is in the order of 100 Solar Mass, as the tidal force is not enough to disrupt the planetary system. Black hole in the order of 1000 Solar Mass is of course more dangerous, but they are as rare as stars with equal mass, so it is not really something to worry about.

There are still thousands of interesting scenarios to try out, and I am still work out on a Black Hole Catastrophic Probability Simulator, which will be capable of simulating more than one scenario, I will upload them later.