NASA has confirmed that an asteroid about a school bus’s size will make its closest approach to the Earth today, September 24. The asteroid is roughly 15 to 30 feet wide and is considered a small near-Earth asteroid. The object will pass the earth at a distance of about 13,000 miles above the planet’s surface.
That is close enough for the asteroid to approach below the ring of geostationary satellites orbiting about 22,000 miles away from Earth. Scientists have estimated the size of the asteroid, known as 2020 SW, at 15 to 30 feet based on its brightness. While an asteroid the size of a school bus seems large, if it were to enter the Earth’s atmosphere, NASA says it will almost certainly break up high in the atmosphere, becoming a bright meteor known as a fireball.
2020 SW was discovered on September 18 by the NASA-funded Catalina Sky Survey in Arizona. Further observations confirmed that the asteroid had an orbital trajectory to high precision, ruling out any chance of impacting the Earth. It has been determined that the asteroid will make its closest approach for 12 AM PDT on September 24 over the southeastern Pacific Ocean.
After its closest approach to the Earth, the asteroid will continue its journey around the sun and won’t return to the vicinity of Earth until 2041. That year the asteroid will make a much more distant flyby of the planet. While this asteroid isn’t a threat to the planet, NASA was given the assignment of trying to find at least 90 percent of the near-Earth asteroids that are about 460 feet or larger in size by Congress in 2005.
It’s very difficult to discover asteroids the 2020 SW size unless they get very close to the earth. NASA is improving its detection capabilities and says that it expects to find asteroid to the size at least a couple of days before they come near the planet.