A space rock belonging to the Aten group of asteroids is expected to fly past Earth at a distance of 2.4 million kilometers today, according to NASA. The asteroid, designated as 2023 WJ1, is travelling at a speed of nearly 18,000 kilometers per hour and is almost as big as an aircraft.
Aten asteroids are a class of Near-Earth Asteroids (NEAs) that have orbits smaller than Earth’s and cross its path. They are named after the first asteroid of this kind, 2062 Aten, which was discovered by American astronomer Eleanor Helin in 1976. There are currently more than 2,000 known Aten asteroids, some of which are considered potentially hazardous due to their close approaches to Earth.
How often do asteroids pass by Earth?
Asteroids are ancient remnants of the early formation of the solar system, about 4.6 billion years ago. They orbit the Sun in different paths and sometimes come close to Earth due to gravitational interactions. NASA monitors these space rocks using a network of ground and space-based telescopes and calculates their orbits and trajectories. The agency also maintains a database of Near-Earth Objects (NEOs), which include asteroids and comets that can come within 50 million kilometers of Earth’s orbit.
According to NASA, there are more than 26,000 NEOs, of which about 2,000 are classified as Potentially Hazardous Asteroids (PHAs). These are asteroids larger than 140 meters that can come closer than 7.5 million kilometers to Earth. However, none of these PHAs pose any imminent threat to the planet, as their orbits are well-known and predictable.
What are the risks and benefits of asteroids?
While asteroids can pose a threat to Earth if they collide with it, they can also offer valuable insights into the origin and evolution of the solar system. Some asteroids may contain water, organic molecules, and precious metals that could be useful for scientific and commercial purposes. NASA and other space agencies have launched several missions to explore and sample asteroids, such as OSIRIS-REx, Hayabusa2, and DART.
NASA also has a Planetary Defense Coordination Office (PDCO), which is responsible for coordinating efforts to detect, track, and mitigate NEO impacts. The PDCO works with other national and international agencies and organizations to develop strategies and technologies to prevent or reduce the damage caused by asteroid impacts. One of the PDCO’s projects is the Asteroid Impact and Deflection Assessment (AIDA), which aims to test the feasibility of deflecting an asteroid using a kinetic impactor.
When will asteroid 2023 WJ1 pass by Earth again?
Asteroid 2023 WJ1 is not a new visitor to Earth. It was first observed on November 2, 1907, when it flew past the planet at a distance of 28 million kilometers. After today, it will not come close to Earth again until January 11, 2039, when it will approach at a distance of 32 million kilometers. The asteroid’s orbit is influenced by the gravity of the Sun, Earth, and other planets, which can cause slight changes in its trajectory over time.
Asteroid 2023 WJ1 is one of the many asteroids that will pass by Earth this month. According to NASA, there are 17 more asteroids that will make their close approaches in December, ranging in size from 6 meters to 340 meters. The closest one will be asteroid 2023 XE6, which will come within 1.8 million kilometers of Earth on December 22.