Potentially Hazardous Asteroids

A gigantic asteroid is heading towards Earth and will pass by in a relatively near distance from the surface. In such a scenario, is it really safe out there? There has been some news regarding a massive “potentially hazardous” asteroid spanning more than the length of the world’s tallest building- Burj Khalifa. The roughly 0.7-mile long asteroid with a speed of 67,000 miles per hour is supposed to fly by our planet on Feb. 4. Before delving into the technicalities of astrophysics, let us take a quick look at what NASA has to say in response to the news relating to asteroids threatening the Earth. In fact, NASA’s Near-Earth Object Observations Program says “there have been no asteroids or comets observed that would impact Earth anytime in the foreseeable future.

All known Potentially Hazardous Asteroids have less than a 0.01% chance of impacting Earth in the next 100 years”. Both ground and space-based telescopes are used by NASA to detect, track and characterize asteroids and comets passing 30 million miles of Earth. The Near-Earth Object Observations Program, commonly called “Spaceguard,” discovers these objects and then analyses their trajectory to characterize the physical nature of these Near Earth Objects. Whether or not this object is hazardous to the Earth is then determined through the data collected by the Spaceguard. There are no known credible impact threats to date only the continuous and harmless infall of meteoroids, tiny asteroids that burn up in the atmosphere.

However, in certain cases with Near Earth Objects (NEOs) larger than 140 metres, the probability of a palpable danger increases. Crashing on the land, they may form large craters and generate a tsunami wave if they hit the ocean. Comparatively, smaller NEOs are not hazardous if they hit the ocean. However, if they hit the land, the risks associated with it can be critical. Most likely, these objects will burn up on entering the Earth’s atmosphere due to friction, but the shockwaves generated due to this explosion can be dangerous. The Chelyabinsk meteor that fell in Russia in 2013 was only 20 meters in diameter and caused damage to over 7,200 buildings and injured 1,491 people. International Asteroid Day is observed every year on 30 June to raise awareness about asteroids and what can be done to protect the Earth, its families, communities, and future generations from a catastrophic event. Asteroid Day is held to commemorate the anniversary of the Siberian Tunguska event that took place on June 30th, 1908, the most harmful known asteroid-related event on Earth in recent history.

In spite of the looming danger, the odds appear to be in our favour. The next encounter with a large NEO, Apophis is expected to be in 2029 and then again in 2036. NASA and the Federal Emergency Management Agency (FEMA) have run three simulated scenarios to assess the prevention methods in case of an asteroid intervention. Scientists have been developing technology that would allow them to deflect asteroids from a distance. They have been working on the Double Asteroid Reflection Test (DART) to develop a technique known as kinetic impactor which would allow them to strike an asteroid approaching Earth by shifting its orbit.

The first test with DART is planned for October of 2022 and then again in 2024. Overall, asteroid interventions have not appeared to be a very troublesome issue in recent history. But, considering the potency and the possible risks associated with an asteroid intervention, scientists from all over the world are together researching upon developing the possible methods and techniques to deflect any harm to our planet due to any astronomical entity.