The enormous 2014 JO25 asteroid that zoomed past Earth on April 19 has sparked discussions about what would happen if we run out of luck and a big-sized object does in fact crash into our planet in the future.
Scientists have studied the chances of such dangerous and massive collisions and they paint a grizzly picture of how the end of the world would look like if an asteroid wipes us out.
To estimate the possible number of casualties and investigate the top fatal effects of an asteroid strike, a team of British researchers from the University of Southampton performed a computer simulation of an asteroid apocalypse.
In their experiment, the scientists sent 50,000 artificial asteroids crashing down all over the globe to analyze how cosmic rocks of different sizes would impact life on Earth.
The team was also able to determine the death toll associated with an asteroid of a given size, using model asteroids with diameters between 49 feet and 1,312 feet.
"The analysis is valid for asteroids up to 400 m (or about 1,312 feet) in diameter, and these asteroids collide with Earth more often than larger asteroids," state the researchers in their paper, featured April 19 in the journal Geophysical Research Letters.
Seven Deadly Immediate Effects Of An Asteroid Collision
According to the study, the most dangerous effects we could expect from an asteroid hitting Earth are:
• Strong wind blasts
• Pressure shock waves
• Flying debris (ejecta)
• Tsunamis
• Seismic shaking
• Thermal radiation
• Cratering
"This is the first study that looks at all seven impact effects generated by hazardous asteroids and estimates which are, in terms of human loss, most severe," states Clemens Rumpf, research lead author.
As expected, the research showed larger asteroids pose more of a risk than smaller ones. For an asteroid to cause human casualties "due to wind blast and thermal radiation," it would have to be at least 59 feet wide.
Likewise, the experiment revealed "the harmful effect of an overpressure shock only became lethal" in the case of asteroids with the minimum size of 131 feet.
This is because asteroids smaller than 33 feet are typically destroyed in the friction with Earth's atmosphere.
How Would Humanity Die In A Catastrophic Space Rock Collision
Of the seven potentially lethal collision effects, the first two were found to be the most substantial in terms of human casualties, accounting for more than 60 percent of lost lives.
The experiment revealed wind blasts of up to 1,000 mph would be fierce enough to heave people off the ground and tear them limb from limb. The simulation also showed such violent winds can collapse buildings and bring down entire forests.
Moreover, spikes in atmospheric pressure were shown to cause shock waves strong enough to rupture internal organs.
"Most of the damage and injuries during that event were caused by the aerodynamic shock that knocked people to the ground and damaged structures and windows, causing indirect injuries by flying glass shards," researchers write in their paper.
Tsunamis Caused By An Asteroid Hitting Earth Not As Devastating As Expected
Real asteroid-produced tidal waves are very different from the Hollywood depiction of apocalyptic tsunamis, the study found.
"A surprising result was that tsunamis are less of a threat than generally assumed in the literature," the team points out in the paper.
Powerful tsunamis would only be responsible for 20 percent of human casualties, mostly affecting cities on the coast line.
Inland cities might be protected from strong tsunami waves, but would still face the wrath of massive fireballs produced by a nearby asteroid impact or explosion.
People unfortunate enough to be right near the impact crater won't need to worry about buildings catching on fire, as they're most likely to be incinerated by fireballs or blown into pieces by overpressure.
Earthquakes and electromagnetic radiation were deemed less worrisome in the event of an asteroid strike, as the study unveiled these would cause only "minor effects."
Flying debris would also pose a reduced immediate threat to mankind, but their long-term effects are potentially catastrophic for life on Earth, particularly in the case of big asteroids.
Long-Term Effect Of Big Asteroid Impacts Equally Lethal
If a large asteroid hit our planet's surface, it would displace a sizeable amount of the Earth's crust, bringing about "long-lasting environmental changes, such as dust deposition in the atmosphere and subsequent dimming of sunlight," added Rumpf.
Debris projected into the atmosphere would block out the sunlight for a long period of time, heating up the air and triggering additional forest fires.
In the absence of light, Earth's vegetation would fade, subsequently leading to the demise of animal species.
This includes humanity, which would die out in a matter of a few years, due to the lack of food and the devastation of the environment.
The good news is big asteroids, exceeding 1,300 feet in size — just like 2014 JO25, which hurled its impressive 2,000-foot diameter safely past our planet — have a small likelihood of crashing down on us.
According to Rumpf, Earth runs the risk of collision with such enormous space rocks only once every 100,000 years.
