You may be familiar with various news about asteroids, ranging from passing asteroids, to asteroids that have the potential to threaten Earth. However, did you also know about asteroids that share orbits with Earth?
In a scientific journal released on February 1, 2022, astronomers provide interesting news, namely the existence of a second asteroid trojan that shares an orbit with Earth. This asteroid is named 2020 XL5.
Asteroid trojans are asteroids that revolve around the sun in the same orbit as a planet. The process of sharing this orbit begins with the incoming asteroid and is finally locked inside the Lagrangian 4 (L4) and Lagrangian 5 (L5) points of a planet.
A Lagrangian point is a spot that has stable gravity, aka a safe orbital point between the sun and Earth. It is often used by astronomers to place spacecraft. 2020 XL5 is a trojan asteroid that is located at the L4 point of Earth, just like 2010 TK7, Earth's first trojan asteroid discovered.
Asteroid 2020 XL5 has a diameter of 10 football fields or about 1.2 kilometers. That size is big enough for an asteroid. Fortunately, despite sharing the same orbit, being at the Lagrangian point keeps this one trojan asteroid locked in position for quite a while.
In addition, trojan asteroids are generally found and share orbits safely on other planets. Reported by EarthSky, Jupiter is recorded to have more than 7,000 trojan asteroids, Neptune has 28 trojan asteroids, Mars has 9 trojan asteroids, and so are the other planets in the solar system.
Being on Lagrangian 4 Earth makes 2020 XL5 orbit the sun in the same distance as Earth or rather lead in front of the earth when orbiting the sun. However, this asteroid will not stay forever at the L4 point of the Earth.
Quoting Toni Santana-Ros' statement in the ESA, even though it is in stable gravity, in the next 4,000 years, minor disturbances from celestial objects other than the sun and Earth will pull the asteroid out of its current position. After thousands of years, 2020 XL5 will again wander in the vastness of the solar system.