An astronomer in Italy captured images of a giant asteroid that will fly relatively close to Earth in early March.
The asteroid, named 138971 (2001 CB21), has an estimated diameter of 1.3 km, nearly four times the height of the Eiffel Tower in Paris. 2001 CB21 will pass by Earth on March 4 at around 3 PM Hanoi time, traveling at a speed of over 43,130 km/h.
Asteroid 138971 (2001 CB21) as seen from Earth. (Photo: Gianluca Masi)
Although classified as a Potentially Hazardous Asteroid (PHA) by NASA’s Center for Near-Earth Object Studies (CNEOS), this object poses no risk of collision with Earth in the near future. While its flyby next month is assessed by CNEOS as a “close approach,” 2001 CB21 will still pass at a distance of over 4.8 million km, more than 10 times the distance between our planet and the Moon.
On January 30, Gianluca Masi, an astronomer at the Virtual Telescope Project in Italy, photographed 2001 CB21 using a ground-based telescope when the asteroid was 34.6 million km away from Earth. 2001 CB21 appeared as a small white dot in the center of the image with an exposure time of 420 seconds. It orbits the Sun with a period of 384 days, similar to Earth’s orbit. Its large size makes it larger than 97% of known asteroids, according to SpaceReference.org.
CNEOS classification does not imply that the asteroid will collide with Earth. Instead, this classification is based on criteria including that the asteroid must be larger than 150 m in diameter and come within 7.4 million km of Earth.
PHAs are not uncommon. Last month, asteroid 1994 PC1 passed by Earth at a distance of 1.9 million km. However, 1994 PC1 posed no collision threat to our planet. NASA is conducting projects like the Double Asteroid Redirection Test (DART) to find ways to deal with asteroids that pose collision risks.
