Astronomers Find A New Trojan Asteroid Sharing Earth’s Orbit


There seemed to be no Trojan asteroids on Earth either, until astronomers found one in 2010 at the L4 Lagrange point, 60 degrees ahead of Earth. Subsequent searches were futile until Pan-Starrs, an automated sky survey in Hawaii, uncovered the 2020 XL5, an intriguing object that appears to be trapped around L4.

However, initial observations were insufficient to pinpoint the object’s trajectory. In 2021, among them Dr. An international team of astronomers, including Santana-Ros, made additional observations of 2020 XL5 using three ground-based telescopes. The team was then able to search through images dating back to 2012, when the asteroid actually appeared, although no one knew it.

Ten years of data was enough to finally solidly graph the elliptical orbit of the 2020 XL5. Dr. “We were 100 percent sure it was a World Trojan Horse,” Santana-Ros said.

While the 2020 XL5 is trapped in an orbit around a stable Lagrangian point, it’s not particularly close to L4. Its elliptical orbit, inclined by about 14 degrees to the orbits of the planets, sweeps it closer to the sun than Venus and almost as far as Mars.

This makes it vulnerable to gravitational blows from other planets, particularly Venus.

The researchers ran computer simulations of the 2020 XL5 orbit, fine-tuning it 800 times. Sometimes the asteroid escaped from the Lagrangian point in 3,500 years; sometimes lingered for 5,000 years or more. But it seems unlikely that the orbit will remain stable for longer than that.

It appears that 2020 XL5 is a dark, carbon-rich body, perhaps a mediator from the main asteroid belt between Mars and Jupiter. Researchers estimate it to be about three-quarters of a mile in diameter, much larger than the Earth Trojan discovered in 2010, which is also located at the L4 Lagrange point.

While the two known Earth Trojans appear to be temporary additions to our orbital neighbor, other objects closer to their stable Lagrangian points may remain in place indefinitely, raising the possibility that some of Earth’s primitive building blocks are still there.



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *