To protect the planet from cosmic dangers, early detection is key. And the recent discovery of an asteroid 1.2 miles (2 km) in diameter suggests that there are still big objects lurking. In 2008, astronomers spotted a small asteroid only 19 hours before it crashed into rural Sudan. This may be a problem, as some surprise asteroids do not miss us. Research suggests that one reason may be that Earth’s rotation creates a blind spot whereby some asteroids remain undetected or appear stationary.
Each of these was discovered only about a day before they passed Earth. An asteroid the size of a 747 jet came close in 2021 as did a 0.6-mile (1-km) wide asteroid in 2012. We can only prevent a disaster if we know it is coming, and asteroids have sneaked up on Earth before.Īn asteroid the size of a football field – dubbed the “City-killer” – passed less than 45,000 miles from Earth in 2019. Smaller asteroids, like the one that exploded over Russia in 2013, can strike Earth without warning, but larger, more dangerous objects have surprised astronomers, too. About 30 new objects are added each week.Ī new mission, funded by Congress in 2018, is scheduled to launch in 2026 an infrared, space-based telescope – NEO Surveyor – dedicated to searching for potentially dangerous asteroids. 14, 2022, astronomers have located 28,266 near-Earth asteroids, of which 10,033 are 460 feet (140 meters) or larger in diameter and 888 at least 0.6 miles (1 km) across. That year has come and gone and, mostly due to a lack of financial resources, only 40% of those objects have been mapped.Īs of Feb. In 2005, Congress passed another bill requiring NASA to expand its search and track at least 90% of all near-Earth objects 460 feet (140 meters) or larger by the end of 2020. While the chances of a larger cosmic body impacting Earth are small, the devastation would be enormous.Ĭongress recognized this threat, and in the 1998 Spaceguard Survey, it tasked NASA to find and track 90% of near-Earth objects 0.6 miles (1 km) across or bigger within 10 years. When the 164-foot (50-meter) asteroid passes by on March 11, 2023, there is roughly a 1 in 500,000 chance of impact. The next asteroid of substantial size to potentially hit Earth is asteroid 2005 ED224. It released the equivalent of 30 Hiroshima bombs worth of energy, injured over 1,100 people and caused US$33 million in damage. In 2013, an asteroid only 65 feet (20 meters) across burst in the atmosphere 20 miles (32 km) above Chelyabinsk, Russia. It leveled more than 80 million trees over 830 square miles (2,100 square km). In 1908, an approximately 164-foot (50-meter) celestial body exploded over the Tunguska river in Siberia. It wiped out most plant and animal species on Earth, including the dinosaurs.īut smaller objects can also cause significant damage. The most famous and destructive impact took place 65 million years ago when a 6-mile (10-km) diameter asteroid crashed into what is now the Yucatán Peninsula.
Larger objects - 0.6 miles (1 km) or more - could have global effects and even cause mass extinctions. If a celestial body of this size crashed into Earth, it could destroy an entire city and cause extreme regional devastation. Near-Earth objects include asteroids and comets whose orbits will bring them within 120 million miles (193 million kilometers) of the Sun.Īstronomers consider a near-Earth object a threat if it will come within 4.6 million miles (7.4 million km) of the planet and is at least 460 feet (140 meters) in diameter. Millions of objects of various sizes orbit the Sun.
0 kommentar(er)
