Recently, the National Aeronautics and Space Administration (NASA) cautioned that an asteroid labelled as 2018VP1 is potentially on a collision course with Earth. This asteroid measures approximately 2 meters in diameter, which is roughly the size of a small automobile. However, NASA has estimated that there’s a mere 1 in 240 chance that this asteroid would indeed impact the Earth.
Remarkably, if it does enter the Earth’s atmosphere, it would likely disintegrate into a fiery ball before reaching our planet’s surface. This type of incident is quite common and usually occurs once every year.
A Deeper Look into Asteroids
Asteroids are also referred to as minor planets. These rocky remnants originated from the early development phase of our solar system around 4.6 billion years ago. Although they’re irregularly shaped, some asteroids are nearly spherical. A multitude of asteroids have a companion moon, with some possessing two moons. Other fascinating types include binary (double) asteroids and triple asteroid systems.
Classification of Asteroids
Asteroids can be sorted into three major categories – Main Asteroid Belt, Trojans, and Near-Earth Asteroids. Most asteroids orbit within the asteroid belt situated between Mars and Jupiter. Trojans share an orbit with larger planets without the risk of collision thanks to their location at special points in the orbit. Near-Earth Asteroids have orbits that closely approach Earth.
Asteroid Collision with Earth
Asteroids larger than 30 meters can cause significant damage upon collision. As per NASA’s Near-Earth Object Observations Programme, asteroids measuring 140 meters or more pose “the greatest concern” due to their potential for catastrophic damage. For the next 100 years, no asteroid larger than 140 meters is anticipated to hit Earth.
Historical Asteroid Impacts: The Chicxulub Impactor
The notorious Chicxulub Impactor, responsible for the extinction of most dinosaur species 66 million years ago, had a massive diameter exceeding 10 kilometers.
Deflecting Asteroids: Available Strategies
Through the years, scientists have proposed various methods to mitigate more serious impact events. These proposals range from detonating the asteroid before it reaches Earth to deflecting its course by striking it with a spacecraft.
The Asteroid Impact and Deflection Assessment (AIDA)
Considered as the most drastic measure undertaken, the AIDA includes NASA’s Double Asteroid Redirection Test (DART) mission and the European Space Agency’s (ESA) Hera mission. The target is Didymos, a binary near-Earth asteroid. DART, which began construction in 2018, aims to impact the smaller asteroid of the Didymos system in 2022. On the other hand, Hera is expected to launch in 2024, and its mission is to measure the impact crater produced by the DART collision and evaluate the change in the asteroid’s orbital trajectory.
