Everyone knows that a giant rock from outer
space hit the planet millions of years ago and wiped out the dinosaurs. Now with advanced technology, researchers
have been able to put together a new timeline showing what really happened. And not only this, they think they know where
the giant asteroid came from. Is Earth the target for another huge space
rock, and would we be able to survive? You’ll be surprised, and probably shocked
at what NASA astronomers recently discovered. So now get ready to experience the disaster
that almost wiped out life completely on Earth. The giant asteroid’s impact into shallow
waters in the Gulf of Mexico 65 million years ago was bad enough. But then an amalgam of additional disasters
ensued: Rocks fell from the sky, wildfires ignited and tsunamis inundated distant shorelines. The researchers found that the first day of
the Cenozoic was peppered with cataclysms and released a new record of this day of chaos
in Proceedings of the National Academy of Sciences. Their timeline was developed using high-resolution
photography, microscopy, computed tomography imaging and magnetic measurements of hundreds
of feet of sedimentary rock recently recovered from Chicxulub, one of the largest impact
craters on Earth…and it all began like this. Imagine you were somewhere in North America
about 65 million years ago, when dinosaurs ruled the Earth, and you were looking up at
the night sky. You would have probably seen what appeared
to be a bright star shining off into the distance. But if you watched this peculiar light for
an hour or two, the object would seem to grow in brightness, but barely move. What you would be looking at is not a star,
but a huge asteroid somewhere between 11 to 80 kilometers wide [7 - 50 miles] on a direct
intercept course with the Earth at 72,420 kilometers per hour [45,000 mph]. Hours later, the asteroid plows through Earth’s
atmosphere heading straight for where the Yucatán peninsula is today. At impacts of that speed, Earth’s atmosphere
acts like water. Smaller space rocks, called meteors, hit the
atmosphere like pebbles thrown into a pond, and decelerate rapidly at high altitudes,
burning away from the friction of the atmosphere, while some bigger pieces of rock survive and
fall to Earth. But the mountain-sized Chicxulub asteroid
hits our atmosphere like throwing a boulder into a puddle. It maintained its velocity and plunged through
the entire 60 miles of atmosphere in just three seconds. The asteroid shrieks over Central America,
emitting the mother of all sonic booms that would shatter eardrums across all the continents. The dinosaurs were likely terrified and running
in all directions having no idea what was just about to happen, but if any animal was
close enough to see the asteroid, they would have been instantly vaporized within minutes. In fact, except for sea turtles and crocodiles,
no four-legged animal larger than 25 kilograms would survive… The mountain-sized space rock falls so quickly
that the air itself cannot escape. Under intense compression, the air heats to
thousands of degrees almost instantly. Before the asteroid even hits, compressed
superheated air vaporizes much of the shallow sea that covers the Yucatán. Milliseconds later, the rock plunges through
what’s left and slams into bedrock. In that moment, a chain reaction of events
occurs. The impacting asteroid exerts so much pressure
on the Earth that soil and rock flow like fluids. The flowing up and down movement of the earth
is like the double-splash of someone doing a cannonball in a swimming pool. The initial splash in all directions is followed
by a delayed vertical splash when the cavity created by the asteroid rebounds to the surface. The first wall of earth gouged outward at
the moment of impact is more than 32 kilometers high [20 miles]. The impact hole nearly breaches Earth’s
mantle, and when the cavity rebounds to form the delayed vertical splash, the Earth rises
at over 1,600 kilometers per hour [1,000 mph] to heights taller than Mount Everest. Within minutes this mountain of debris almost
entirely collapses in a series of secondary explosions, leaving behind a smaller mound
called a crater’s peak ring. At the same moment the asteroid strikes the
Yucatán and applies its pressure to the bedrock, it converts the kinetic energy of a 7.5 billion
ton rock traveling 16 kilometers per second [10 miles per second] into searing heat in
an instant. The Chicxulub impactor delivers approximately
one septillion, three hundred sextillion kilojoules of energy [1,300,000,000,000,000,000,000,000]
More energy than one-billion Hiroshima atomic bombs. The kinetic energy transferred by the asteroid
to the soil, rock, and air excites the molecules to temperatures far hotter than the surface
of the sun. The heat rips electrons from atoms, ionizing
the air into an expanding fireball of plasma in excess of 10,000 degrees turbocharged with
vaporized rock that is blasted out at hypersonic speeds. The heated, rapidly expanding air and near-instantaneous
conversion of earth to gas combined with the impact shockwave itself forms a massive blast
wave of pressure expanding outward at more than 1,600 kilometers per hour [1,000 mph]. If this asteroid hit the same spot today,
the blast wave would vaporize you in Texas, deafen you in New York, and blow out glass
windows in Buenos Aires. The Chicxulub impactor rings Earth like a
bell. Waves in Earth’s crust radiate away from
the impact zone at 4 kilometers per second [2.5 miles per second]. These waves then trigger fault-slipping earthquakes
across the continents. If you were on the other side of the world,
you would feel the ground-shaking 30 minutes after impact. The impact triggers tsunamis as high as skyscrapers. The first of them hit gulf coastlines within
the hour. Waves ranging from 600 feet to perhaps as
tall as a 1,000 feet smash into what is now Mexico and the southern United States and
flood tens of miles inland. The waves temporarily reverse the flow of
rivers, rushing up river beds like 30-foot tidal bores. Tsunamis smash into the eastern coast of the
United States, and six hours after impact, max out at 600-foot-high walls of water that
slam into Europe, Africa, and the Mediterranean coasts. Within 15 hours of impact, waves arrive on
every coastline on the planet. Depending on local topography, the ocean sweeps
away anything in its path and sucks it back to the sea when the waters finally retreat. It already sounds like Armageddon, but even
more disasters are on their way. When the big rock strikes, its splash accounts
for 25 trillion tons of earth that it launches on ballistic trajectories, some at speeds
that exceed Earth’s escape velocity. These rocks exited Earth’s gravitational
pull to either orbit the Sun, and some of this material probably reached the moon. But the majority of ejected debris returned
back to Earth within the hour. These glass-like chunks, called tektites;
some as large as buses, but most the size of marbles, pelt the earth at speeds ranging
from 160 to 320 kilometers per hour [100 to 200 mph] in lethal quantities. Regardless of where any remaining dinosaurs
were on Earth, they were hit with this fiery hailstorm. But these glass bullets didn’t need to hit
the dinosaurs to be fatal. As these tektites fall, their friction with
the atmosphere emits enough thermal radiation to set fires across the planet. By some estimates, the combined heat of the
returning embers heats the planet to the equivalent of an oven set to broil. Most of the world’s trees burn, which is
perhaps why the only bird species that survive the impact are those that nest on the ground. Of the few larger land animals to avoid extinction,
nearly all have some means of escaping the heat. They either could burrow like small mammals,
snakes, and lizards, or escape into water, like crocodiles or turtles. Even if the poor dinosaurs were on the other
side of the world, they would have needed to find protection from the initial heat blast. In a final piece of terrible luck for the
dinosaurs, Chicxulub happens to strike an area rich in oil and sulfur. The impact ejects 100 billion tons of vaporized
sulfur and 30,000 quadrillion gallons of water into the atmosphere, which then condenses
into massive storm clouds and falls back as torrents of acid rain that acidified the oceans. In the higher latitudes, continental-wide
snow storms deposit tens of feet of snow per day. But the global deluge doesn’t last long,
because in addition to water, Chicxulub vaporizes and explosively ejects 150 football stadiums
worth of oil from the Yucatán bedrock. This oil condenses in the stratosphere as
a black sooty layer covering the Earth like a coat of black paint. Unlike the sulfur and wildfire smoke, the
carbon circulates high above the cloud layer stopping it from raining back down. And that becomes another big problem. The soot layer remains in the atmosphere,
reducing the amount of sunlight that reaches Earth’s surface by 90 percent for at least
two to three years. The initial ovenlike heat brought on by the
returning tektites is followed by a deep and long-lasting freeze. Global temperatures drop by an average of
almost 50 degrees. The only places on Earth to avoid this deep
freeze are Madagascar, India, and Indonesia, which were tropical islands during this time. In the global chill, evaporation almost ceases
dropping rainfall by 80 percent. Nearly every spot on earth outside of these
tropical islands dries into a desert. Where did this giant rock come from, and is
there another one out there headed for us? Researchers using a supercomputer studied
asteroid evolution using data from known asteroids. The two-member team of Avi Loeb and Amir Siraj,
suggested that the Chicxulub asteroid likely originated from the Oort cloud; a sphere of
debris at the edge of the solar system. It could have been a much larger comet that
was pushed off course by Jupiter’s gravitational field and sent close to the sun where it broke
into several pieces. These fragments can cross the Earth’s orbit
and hit the planet once every 250 to 730 million years. Judging from this study, it’s not a matter
of if we could be hit by another giant rock from outer space, but when. On Saturday, December, 11, 2021, NASA revealed
that a 330-meter long asteroid named 4660 Nereus screamed past Earth around 3.8 million
kilometers [2.4 million miles] at a speed of 6.5 kilometers per second [14,719 mph]
While you might not think that is very close, any slight deviation in its orbit could put
it on a direct course with us and smash into the Earth in the future. Astronomers are tracking this potentially
hazardous rock and say it will come within 1.1 million kilometers [745,000 miles] of
Earth on Valentine’s day in 2060. Buy your flowers and get those proposals done
early just in case! Keep in mind the asteroid that caused the
Chelyabinsk explosion in Russia in 2013 was just 20 meters in size. The bad thing is that we don’t have any
known way to defend the Earth from a giant space rock. However, NASA’s DART mission, or double
asteroid redirection test, will try to see if a spacecraft can autonomously navigate
to a target asteroid and intentionally collide with it, causing an kinetic impact that could
push the asteroid off a collision course with the earth. DART’s target is Dimorphos; an asteroid
moonlet which orbits a larger asteroid named Didymos. The spacecraft is set to arrive in late September
2022 when the Didymos system is 11 million kilometers [7 million miles] from Earth. However, it is estimated that the collision
will change the speed of the moonlet by a fraction of 1% Stopping a 10 kilometer wide or bigger asteroid
hurtling towards the planet at more than 72,000 kilometers per second will take a lot more
than a small spacecraft impacting it, perhaps the world would need to try nuclear weapons
like in the movie Armageddon. Maybe you have an idea how we could stop a
world ending asteroid, and you’ll become famous! Let us know what you think, and make sure
to stay tuned here for more exciting stuff happening in our universe. Thanks for watching. Congratulations! Our channel has reached over a million subscribers! We thank you, friends, and we are very happy
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