Oceans make up 70 percent of the Earth's surface, which makes them a likely candidate for an asteroid strike — if and when it happens. But the consequences of the impact are poorly understood…
We see in movies such as 'Deep Impact' and 'Armageddon' that an asteroid impact creates a mega tusumani that wipes out everything on the land. But researchers find this depiction inaccurate.
Let's be clear, getting hit by an asteroid will likely end all life on earth. In fact, the famed physicist, Stephen Hawking, has warned that humanity could vanish in the next 1,000 years because of an impending asteroid collision.
Asteroid impacts like the one that struck what is now Chicxulub in Mexico some 65 million years ago — which is believed to have dealt dinosaurs the final deathblow — are rare. But small space rocks hit earth more often than you think. Remember, the meteor explosion that blasted through the atmosphere in Chelyabinsk, Russia, in 2013? NASA say "Every day, Earth is bombarded with more than 100 tons of dust and sand-sized particles."
Breakdown of the impact
The threat from a devastating tsunami is real if the impact occurs within 10-20 kilometers off the coast. But, if the collision takes place in the middle of the ocean, the massive waves generated would quickly die down.
This simulation from Los Alamos National Laboratory shows that if an asteroid struck the ocean, it would create a transient crater, launching a splash curtain into the air. A larger threat may come from the large amounts of water vapour lofted into the atmosphere
An asteroid impact only affects the immediate region, and to create a tsunami, you need something that disturbs the entire water column. Most tsunami are caused by large earthquakes on the sea floor when slabs of rock move past each other suddenly, causing the overlying water to move.
But, it doesn't mean that the impact on ocean will be less devastating.
The collision would result in billions of tonnes of water (in the form of water vapour) being thrown into the atmosphere. The researchers say it could linger in the atmosphere for years. As we know, water vapour is a potent greenhouse gas, so its presence in the atmosphere for such a long duration will drastically alter the climate.
What if it strikes on land?
NASA astronomer Don Yeomans wrote in an opinion piece for The New York Times: "Should an object of that size (the one that hit Mexico 65 million years ago) hit Earth, it would cause a blast with the energy equivalent of about 2.4 million tons — or 2.4 megatons — of TNT explosives, more than 180 times the power of the atomic blast that levelled Hiroshima." The impact will be so strong that some of the resulting debris will be thrown out of the Earth's atmosphere. While the rest will block out sunlight for a long time. Without sunlight, much of Earth's flora and fauna will die.
Do you fear an asteroid hitting earth? And are we equipped to handle it? Let's know your views in the comments section below.