Alien Life May Have Been Wiped Out by Explosions

According to a new line of thinking among astrobiologists, it may be that one of the main reasons why we have yet to hear from, or make contact with, extraterrestrial civilizations is the fact that powerful, violent cosmic events wiped them out.

There are plenty of possible culprits for such a scenario, scientists reveal, starting why gamma-ray bursts (GRB) and cosmic ray emissions, and ending with energetic supernova explosions.

The latter type of events is especially dangerous, because it occurs all over the place, at all locations were stars exist. There are two primary types of supernova events, of which one is of reduced intensity, whereas the second is very brutal in its effects.

Type Ia supernovae occur in binary systems that contain a helium-burning white dwarf. The star accumulates material from its companion until it finally exceed a certain threshold. When this happens, it ejects the excess material in a massive thermonuclear explosion.

If the white dwarf is not destroyed in the process, then this dance of death can begin anew. On the other hand, Type II supernovae occur through an entirely different mechanism. These phenomena take place when a massive star reaches the end of its burning cycle.

When this happens, its core collapses into a neutron star or a black hole, which releases massive amounts of gravitational potential energy. The material making up the star's atmosphere is ejected at speeds exceeding 10 percent the speed of light, or 30,000 kilometers per second.

The ensuing shock wave spreads through the former star's surrounding, bathing everything in massive doses of radiations, which nothing can escape. If the star is located in a large-scale formation such as the Milky Way, then it may affect an entire galactic sector.

Given the large number of massive stars spread throughout the Universe, and the small chances complex life has of developing in the first place, it stands to reason that numerous things would have to align themselves properly in order for an alien civilization to be able to make contact.

However, this should not discourage us from continuing to send messages through the vastness of space, astrobiologists say. There could be instances in which alien life managed to develop to a point where technology enabled those lifeforms to escape imminent peril.

If that is the case, then we should strive to make contact, in order to avoid a similar fate.