So, what are black holes? When I was younger black holes scared me so much, I swore one was going to destroy our world.
My irrational fear of them grew once I learned that there were black holes that traveled throughout the universe, swallowing up galaxies and planets. Who wouldn’t be afraid of such darkness and power?
Well, my fear of black holes subsided as I grew older and my fascination with them only rose. They are one of the most potent things we know of in the known universe, and now we have our first known picture of a black hole, and it is fascinating, intriguing, and awe-inspiring. So how did we get here and exactly what is a black hole?
First black holes reflect no light, it’s a body of blackness, gravity so powerful that it distorts time and space. Most black holes are given birth to by supermassive star that has died out. When these stars die out, they start absorbing mass from their surroundings.
By incorporating other stars and merging with other black holes, they become supermassive black holes. So far many of these massive black holes live in the center of most galaxies, such as our own called Sagittarius.
Three Known Types Of Black Holes
Different types of black holes, three types of these are stellar, supermassive, and miniature black holes – depending on their mass.
A stellar black hole is created when a star collapses upon itself, creating such powerful gravitational forces that no light escapes it. Supermassive black holes more than likely have the mass equivalent to billions of suns, most if not all exist in the centers of most galaxies, including the Milky Way.
As of now, we don’t know precisely how supermassive black holes form, but it’s likely that they’re a byproduct of galaxy formation making it one of the most powerful and destructive forces in our known universe. Lastly, we have miniature black holes which formed when the universe started 13.7 billion years ago.
No one has ever captured an image of a miniature black hole, which has the mass equal to or less than our sun, but it is believed they formed right after the big bang from the rapid expansion.
First Captured Images
The image is a result of work carried out over ten years by the Event Horizon Telescope (EHT) Collaboration. Radio telescopes from around the world were used to capture the image.
Telescopes focused on a pair of supermassive black holes – the one at the center of the Milky Way galaxy, known as Sagittarius A*, and a second that lies at the heart of an elliptical galaxy called M87.
For instance, the black hole Sagittarius A*, at the center of the Milky Way, is about 4.3 million times the mass of our sun, while the black hole at the heart of the M87 galaxy, which it has now released an image of, is about 6 billion solar masses.
The bright orange ring captured is called the event horizon. Capturing the first-ever photos of a black hole is a monumental feat of human engineering and marvel. It is mind-boggling that scientists were able to capture an image of a black hole from a distance of approximately 55 million light-years away.
So why didn’t scientists photograph Sagittarius A*? We are not in the right position to capture a photograph of our own black hole. The milky way is around 150,000 to 200,000 light-years across.
The milky is shaped in a spiral, with arms filled with hundreds of billions of stars.
There is too much stuff in the way including stars, planets, gas, and dust to capture our own black hole. Radio telescopes are capable of carving through a lot of the cloudy rubble and light that hides our view of Sagittarius A*.
Another factor in not being able to capture a clear of our own black hole is due to how much its signal changes, and how rapidly those changes occur.
The event horizon telescope (EHT) managed to capture the next best thing, and that was M87, the supermassive black hole at the center of galaxy Messier 87, proved to be the perfect first candidate for observation due to its enormous size and consistency.
What Now and What Does This All Mean?
The pictures of M87 will usher in a new era of astronomy. It’s an achievement that took supercomputers, eight telescopes stationed on five continents, hundreds of researchers, and vast amounts of data to accomplish.
We are the first humans ever to see a black hole and the results helped to confirm (again) Einstein’s theory of general relativity. M87 is a supermassive black hole the size of our galaxy, just to give you a reference of its enormity.
Researchers were able to capture an image of a black hole, verify Einstein’s theory of relativity, researchers also wanted to understand more about how black holes grow and what makes material orbiting the black hole eventually fall in, and they also wanted to get a better idea of why and how supermassive black holes at the center of some galaxies, like elliptical galaxy M87, seem to propel massive streams of subatomic particles out of the galaxy and into the broader universe.
Hopefully in time scientist will be able to answer more questions about black holes, so far Sagittarius A* and M87 are two different types of black holes.
For me, black holes represent maybe a one-way exit out our universe, or they could be the glue that keeps our galaxies together, whatever you think black holes are and what they do, scientists are a step closer to unlocking one of the universe most exotic and destructive forces out there.