The collision of 2 black holes can be seen from Earth.

Observing celestial bodies from Earth has always been a source of curiosity and research on the part of scientists. Every day you can witness a different phenomenon. However, certain things are more aware than others.
The behavior of black holes, for example, has always been on the radar since 1783 when they first introduced the concept of a body so dense that not even light could escape it; Over the years, it was followed by different types of research and experts who wanted to develop a theory about it.
It was not until 2019 when the international Event Horizon Telescope consortium presented the first image ever captured of a supermassive black hole located in the center of the galaxy M87.89, a historic milestone for the scientific community.

Although they have no impact on Earth, black holes offer a different spectacle. They have just reported that a collision of two of them is expected to occur in the galaxy SDSS J1430+2303 about a billion light-years from our planet.
Because the combined mass of both objects is 200 million suns, their collision is now one of the most anticipated cosmic events of the year.
To know the event’s impact, it is necessary to know that black holes grow due to the accumulation of matter they trap. It can be gas from stars or smaller holes. Although they have been the subject of study for several years, new unknowns appear that cannot be answered each time.

In an investigation by Astronomy & Astrophysics, they believe that the holes considered binary due to their closeness will collide in the next three years, unlike most binaries that will collide in millions of years.
Scientists have said they are not yet sure what the collision will look like but hope that if it is visible even without an instrument that can detect low-frequency gravitational waves, it is likely that at least one huge burst of light will be seen in the spectrum, telling them how this event unfolded.