In 2023, numerous celestial bodies are approaching Earth within a range of 0.05 astronomical units (approximately 7.4 million km), one of which is twice the height of the Burj Khalifa.
So far, scientists have identified over 30,000 near-Earth objects (NEOs), a term used to refer to any celestial object with an orbit that brings it close to the orbit of our planet. The majority of NEOs are asteroids, although more than a hundred comets are also included in this category.
Some NEOs are classified as “potentially hazardous“. These are objects with a diameter greater than 140 meters and orbits that come within 0.05 astronomical units (approximately 7.4 million km, or 0.05 times the distance from Earth to the Sun) of Earth’s orbit.
In fact, there are currently no known potentially hazardous objects that scientists believe have a chance of colliding with Earth in the near future. The definition of a potentially hazardous NEO simply means that, in the distant future, their trajectories may evolve into orbits that could impact Earth. In the event of a collision, NEOs large enough could cause significant damage to our planet, at least on a regional scale.
Below is a list of the largest potentially hazardous NEOs – all of which are asteroids – that will pass close to Earth in 2023, meaning they will approach the planet within 0.05 astronomical units, according to data from NASA’s Center for Near-Earth Object Studies (CNEOS).
363505 (2003 UC20)
This is likely the largest asteroid approaching Earth this year. CNEOS data indicates it has a diameter of approximately 1.9 km, which is 2.3 times the height of the Burj Khalifa (828 m), the tallest building in the world located in Dubai. This colossal object takes 252 days to orbit the Sun and will pass by Earth on November 2 at its closest distance of 5.2 million km, traveling at a speed of 7,971 km/s.
Orbit simulation of 363505 (2003 UC20) and Earth around the Sun. (Image: Space Reference).
199145 (2005 YY128)
This asteroid is estimated to have a diameter ranging from 0.566 to 1.265 km, making it nearly the size of the Golden Gate Bridge. 199145 (2005 YY128) completes an orbit around the Sun every 774 days. It will approach Earth closest on February 16 at a distance of 4.6 million km, traveling at a speed of 24,649 km/s.
436774 (2012 KY3)
CNEOS data indicates that 436774 (2012 KY3) has an estimated diameter ranging from 0.538 to 1.202 km, slightly smaller than 199145 (2005 YY128). This asteroid has an orbital period of 500 days around the Sun and is expected to come closest to Earth on April 13, at which point it may be 4.7 million km away, traveling at a speed of 17,552 km/s.
Orbit simulation of 436774 (2012 KY3) and Earth around the Sun. (Image: Space Reference).
139622 (2001 QQ142)
Based on its brightness and how it reflects light, 139622 (2001 QQ142) likely has a diameter ranging from 0.347 to 1.552 km. It completes one orbit around the Sun every 620 days. At its closest approach to Earth on December 6, the object will be about 5.5 million km away and traveling at a speed of 6,660 km/s.
349507 (2008 QY)
349507 (2008 QY) orbits the Sun every 461 days. CNEOS data shows it has a diameter ranging from 0.518 to 1.159 km. This space rock will come closest to Earth on October 3 at a distance of 6.3 million km, traveling at a speed of 20,960 km/s at that time.
