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. When they do appear, how prepared will humanity be? Surprise asteroids have visited Earth in the past and will undoubtedly do so in the future. To date, NASA has tracked only an estimated 40% of the bigger ones. To find the answers to these questions, one has to know what near-Earth objects are out there. “A more recent theory, based on detailed studies of the largest M-type asteroid, 16 Psyche, argues that these bodies formed much closer to the sun, were stripped of their thin crusts while still partially molten, and later dynamically moved to their current location.As a scholar who studies space and international security, it is my job to ask what the likelihood of an object crashing into the planet really is-and whether governments are spending enough money to prevent such an event. “For many years, M-type asteroids were thought to be the cores of planetesimals, or small planets, stripped of their silicates and organic mantles by collisions in the early solar system,” said Noemí Pinilla-Alonso, a planetary scientist with University of Central Florida ’s Florida Space Institute, who is using the new Two-meter Twin Telescope (TTT) in the Canary Islands, Spain, to study metal-rich M-type asteroids. Metal asteroids are considered the probable source of iron meteorites found on Earth. Earth has a metal core, a mantle and crust. It’s one of the most massive objects in the asteroid belt. NASA/Ben Smegelsky Failed Planetġ6 Psyche is a rare metal asteroid possibly comprised of iron, nickel and gold, but that’s based only on observations of its brightness made by telescopes.Īround 173 miles (279 kilometers) wide, it’s thought to be the core of a failed planet, which makes it of great interest to planetary astronomers. near the agency’s Kennedy Space Center in Florida on Dec. A team prepares NASA’s Psyche spacecraft for launch inside the Astrotech Space Operations Facility.
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