Space is a mysterious place full of bizarre beauty. Despite its wondrous nature, it can prove to be deadly in specific, yet surprisingly common, circumstances. Anyone exploring the universe faces a variety of ways to die in outer space, thanks to the inhospitable nature of the endless vacuum of the void. Everything from solar radiation to a lack of oxygen can spell doom for astronauts. However, you don’t have to travel away from the planet in a rocket to be susceptible to many dangers our galaxy has to offer.
Scientists who have looked at just how space could kill us all have found plenty of different methods of destruction. Planets are constantly being swallowed by exploding stars, while black holes are capable of sucking anything that gets close enough into oblivion. There are even bizarre things you didn't know about outer space that include weird weather or other phenomena that could easily wipe out humanity under the right circumstances. Unfortunately, there’s basically nothing we can do to protect against these threats, other than hope they never happen near Earth.
A gamma ray burst is a huge amount of energy that is released as radiation when massive stellar objects collide or collapse into themselves. Gamma ray bursts, AKA GRBs, are the most powerful electromagnetic event that has been observed, even though they last for just a few seconds. These gamma ray bursts occur almost continuously throughout the universe, but are usually so far away their effect is hardly noticeable from Earth.
A gamma ray burst from less than 1,000 light years away, however, could cause significant damage. The electromagnetic energy could easily disrupt the satellites in orbit around the planet, making them completely useless and destroying much of the technology humans rely on. Any event that was closer would risk wiping out the protective ozone layer, putting all life at risk of death from the sun’s ultraviolet radiation.
Fortunately, in a 2006 study published in Astrophysical Journal, researchers found that GRBs mostly occur in small, metal-poor galaxies. The researchers estimated the likelihood of a gamma ray blast happening in the metal-rich Milky Way Galaxy is less than 0.15%.
Despite their stationary appearance, stars are actually all moving at incredibly fast speeds. However, there are some that are even quicker, and capable of moving through space at tens of thousands of kilometers every second.
Called "hypervelocity stars," they travel across galaxies and pose a huge threat to anything they come across, since they're functionally giant balls of nuclear explosions. This means they could pull a planet like Earth out of orbit, boil it to destruction, or even crash directly into it, and there would be nothing anyone could do to stop it from happening.
A solar flare occurs when the sun has a sudden increase in energy in a specific area. This causes a bright spot to appear on the surface, as the star releases clouds of particles such as ions and electronics (along with electromagnetic waves) in a vast explosion. Flares can range dramatically in potency, but the most powerful ones could pose hazards to life on Earth. The worst cases result in coronal mass ejections that involve plasma being propelled out into space.
If this plasma reaches the planet, it can cause geomagnetic storms. Essentially, it could effectively turn off the electricity across the world. Anything that runs off an electrical current would no longer function, meaning everything from the internet to medical equipment would stop working. For a society that relies so heavily on technology, such an event could cause a huge amount of death and destruction.
In October 2017, Avi Loeb and Manasvi Lingam from Harvard University hypothesized that such an event could happen within the next century.
Exactly how galaxies are able to grow has been a question that has puzzled astronomers for centuries - until the idea of Galactic Cannibalism was first introduced in 2003. This amazingly-named process sees a large galaxy collide and merge with a smaller galaxy through gravitational interactions.
The end result is a new galaxy formed in an irregular manner. Considering how the Milky Way galaxy is much smaller than the Andromeda galaxy, and given the relative closeness of the two, it is possible our own galaxy could be cannibalized in this way. The huge gravitational forces involved and the chance of collisions between stars and planets would prove deadly to any lifeforms caught up in the event.