NASA Releases Information on Near-Earth Asteroids
NASA has recently released information regarding the number of near-Earth asteroids, highlighting the importance of its “Planetary Defense” mission. The goal of this mission is to identify and track asteroids that may potentially collide with Earth, preventing large-scale damage and ensuring the safety of our planet.
However, detecting these asteroids is no simple task as they do not emit light. The primary method used for detection is when the asteroid’s surface reflects sunlight into telescopes. In order to increase the chances of identification, more and more telescopes are being designed specifically to hunt for asteroids and are operating tirelessly. As of August, there are already 32,000 known near-Earth asteroids.
Both amateur and professional astronomers have been contributing to this research effort by submitting over 405 million observations to the Minor Planet Center, a core hub for NASA’s planetary defense strategy and an information clearinghouse for asteroid hunters.
Among the 32,000 near-Earth asteroids, over 10,000 are estimated to be larger than 140 meters in diameter. These asteroids have the potential to cause significant destruction, as demonstrated by the impact of the asteroid that hit the Chelyabinsk region of Russia in 2013. Measuring 20 meters in diameter, it shattered windows and injured nearly 1,500 people. An asteroid seven times its size would be even more destructive if it were to make impact with the ground.
What is most concerning is that more than half of the 140-meter-wide asteroids (over 14,000) have yet to be discovered. This means that there is a high likelihood of a catastrophic collision with Earth, as we are unaware of the exact path these asteroids may take. Additionally, around 50 asteroids with a diameter of 1 kilometer remain undiscovered. If one were to strike Earth, the impact would be devastating on a scale much larger than a single city.
To put this into perspective, the asteroid that is believed to have caused the extinction of the dinosaurs is estimated to have been around 10 kilometers in diameter. Ensuring human safety from potential asteroid collisions will require a significant amount of effort. It is crucial for people to join the hunt for these asteroids, as every contribution, no matter how small, can make a difference.
(The Taipei Planetarium has kindly given permission for the reprinting of this article; first image source: Pixabay)