Scientists have discovered two massive black holes at the center of their individual galaxies, which are about to collide.

Such an event is not very rare as there are about 200 billion galaxies in the universe and it is very normal for two galaxies to collide.

Astronomers have observed the merging of two galaxies, but they have never before witnessed the ending process of galaxies, which is the outcome when two black holes collide with one another and release violent cosmic energy.

Scientists from the U.S. National Aeronautics and Space Administration's (NASA) Jet Propulsion Lab and Caltech believe that the unusual light signal, examined from quasar PG 1302-102, is a result of the two black holes in the system on a collision course.

The collision of the gigantic black holes can release energy the equivalent of up to 100 million violent supernova explosions.

George Djorgovski of the California Institute of Technology explained that much of the released energy will cause gravitational waves, which may disturb nearby celestial objects as well.

Scientists have observed supermassive black holes that are separated by many light-years; this, however, is the first instance that the two black holes are just one light-year apart.

"This is the most convincing evidence for a tight pair of black holes with a separation smaller than the solar system," said Avi Loeb, a cosmologist at the Harvard-Smithsonian Center for Astrophysics who was not involved in the study.

The scientists posit that the black holes do not emit light. However, the gases that are swirling around the black holes at high speed are emitting light.

"When you look at the emission lines in a spectrum from an object, what you're really seeing is information about speed -- whether something is moving toward you or away from you and how fast. It's the Doppler effect," said Eilat Glikman, an assistant professor of physics at Middlebury College in Vermont, who is also co-author of the paper.

Quasars usually have a single emission line, but the scientists discovered that the quasar is emitting two lines and at different speeds.

Experts suggest that interpretation of the phenomenon is still very uncertain; however, the merger can provide significant information about galaxy evolution and formation.

The paper was published in the journal Nature.