Around 66 million years ago, the earth was lush with greenery, and the dominant species on the blue planet was dinosaurs. However, the stability of the earth was shattered when a giant space rock hit the planet with its full fury. The asteroid impact was so powerful, and it wiped out several species from the surface of the earth including dinosaurs. Since then, no such asteroid with a devastating magnitude has hit the earth, and it has played a crucial role in determining the evolution of humanity. And now, the whole planet is observing the world asteroid day on June 30, the anniversary of the Siberian Tunguska event, one of the powerful asteroid hits humans have witnessed.
Asteroids: Threat from space
According to NASA, the United States space agency, there could be more than one million asteroids in space that have the potential to hit the earth. However, just one percent of these asteroids have been detected by humans, and it includes the Apophis and Bennu, which could pose a threat to planet earth in the future during the time of their close approaches.
Even though most of the small asteroids and near-earth objects will burn down during their re-entry, rocks of considerable size could survive the atmospheric re-entry and could cause a mid-air explosion. If an asteroid with a huge size succeeds in re-entering the atmosphere, it could hit the earth at a mindblowing speed and could cause considerable damage to the impacted region. Fortunately, NASA reveals that no asteroid is posing a threat to the existence of humans in the near future.
Asteroid impacts are not confined to the past
Even though people in the present generation could be safe from potential asteroid hits, space experts strongly believe that giant space rocks could hit the blue planet one day or another. Dr Iain McDonald, a scientist at the Cardiff University's school of earth and ocean sciences strongly believes that earth will be inevitably hit by an asteroid in the future. According to McDonald, events like devastating asteroid hits are not just confined to the past, and it could happen in the future too.
McDonald is not the only space expert who expects an asteroid hit in the future. Popular American physicist Neil deGrasse Tyson during his talk in a podcast titled 'Cosmic Queries: Asteroids and Comets' had also shared similar views.
"It is an intriguing and under-appreciated fact that asteroids and comets may have been the bringers of life, if not the ingredients of life, but perhaps even life itself. And yet, they can also serve as harbingers of doom for the very life that they brought to the planet," said Tyson.
Earth's defense against potential asteroid hits
Even though no asteroid will hit the earth in the near future, space scientists are working hard to develop a planetary defense mechanism to protect humanity from a space rock impact. There are several proposed theories to deflect the asteroid from its collision course. One theory put forward by scientists is to hit an approaching asteroid with a giant space vessel so that its collision course trajectory could be changed.
If the asteroid is very big, this method will not work, and the only solution left before us will be nuking it. However, several space experts believe that nuking an asteroid will be a bad idea, as it could result in radioactive rain which will harm life on earth.
