‘Potentially Dangerous’ Asteroids Cross Earth Orbit in December


Asteroids: The National Observatory announced on Tuesday (7) that two asteroids classified by NASA as Potentially Hazardous Objects (PHO) will make their closest approach to Earth on December 11 and 17. The two space rocks are also considered Near-Earth Orbiting Objects (NEOs).

It is important to emphasize that, despite the astronomical classification, the two objects do not present any risk of collision with our planet. The classification of “potentially dangerous” is assigned by NASA to any asteroid that is more than 140 meters in diameter and an approach of at least 7.48 million kilometers to Earth.

Within these parameters, the first asteroid to approach our planet is the 4660 Nereus, with 330 meters in diameter, which will pass at a distance of 0.0263 astronomical units (au). As each au corresponds to 150 million kilometers, this object will reach a distance of about 3.95 million kilometers from Earth, the equivalent of more than ten times the average distance from the Moon.

Understanding asteroids

A week before Christmas Eve, it will be the turn of the asteroid (163899) 2003 SD220, this one with approximately 791 meters in diameter, to pass “close” to Earth, according to the Brazilian observatory. As the maximum approach will be 0.036 au, this means a distance of 5.4 million kilometers, or almost 14 times the average distance to the Moon.

According to the astronomer of the National Observatory Filipe Monteiro, although the 4660 Nereus and the (163899) 2003 SD220 cross the orbit of our planet, they are part of distinct subgroups, the first being an Apollo and the second an Aten. The Atens have a smaller orbit than Earth, while the Apollos have a larger orbit than our planet.

Although the two asteroids do not pose any risk of collision with Earth, “observations of these objects are essential to better assess the evolution of their orbits”, explained the astronomer. Cercanias da Terra at the National Observatory) leads research in this area.