Scientists continuously monitor Earth-crossing asteroids, whose paths intersect Earth's orbit, and near-Earth asteroids that approach Earth's orbital distance to within about 28 million miles (45 million kilometers) and may pose an impact danger. Radar is a valuable tool in detecting and monitoring potential impact hazards. Lindley Johnson is NASA’s planetary defence officer told VOA that a hit from Bennu would not destroy all life on Earth. If it does crash, it may create a crater about 5-10 km wide. Asteroid Bennu is assumed to be about 500 meters wide. According to an article by science writer Jesse Emspak published in BBC Future, major asteroid strikes are rare. Bennu is classified as a “potentially hazardous asteroid,” meaning the object is more than 460 feet (140 meters) wide and could theoretically come within 4.65 million miles of Earth. A 2014 The previously most recent confirmed impact crater was the famous Meteor Crater in Arizona, created about 49,000 to 50,000 years ago, measuring 1.2 km in diameter - slightly smaller than Yilan Medium-sized asteroids hit Earth frequently without major devastation, but there is more to an asteroid impact than meets the eye. Impacts can cause other hazards that can last for years, and a planetary defense preparedness strategy should address not just the initial impact but also these second-order “cascading” hazards. Collisions with asteroids, comets and other stuff from space have been responsible for huge landmarks in our planet’s history: global shifts in climate, the creation of our moon, the reshuffling of our deepest geology, and the extinction of species. Asteroid threats pop up in the news every now and then, but the buzz tends to fizzle away as Asteroid impacts pose a major threat to all life on Earth. The age of the dinosaurs was abruptly ended by a 10-km-diameter asteroid. Currently, a nuclear device is the only means of deflecting But life on Earth has been drastically altered by asteroid impacts before; the Chicxulub crater, for example, is evidence of the planet-shaking strike that led to the extinction of the non-avian .

major asteroid impacts on earth