Earth has an extra companion, a Troy asteroid that will linger on earth for 4,000 years

2022-05-08 0 By

It is the second Earth-trojan asteroid ever discovered, and the largest of its kind ever.In 2020, astronomers thought they’d found something incredible: a second so-called Earth Trojan asteroid.Now, a new team of researchers has confirmed it’s true.A Trojan asteroid is a small space rock that shares an orbit with a planet, orbiting any host star in which the planet is in a stable orbit.While troyi asteroids have been discovered around other planets in our solar system and beyond, so far only one object, called 2010 TK7, has been confirmed to follow the same orbit as Earth.In a new study, researchers confirmed that an asteroid discovered in 2020 called 2020 XL5 is the second of its kind, called an Earth-Trojan asteroid.Think of it as earth’s extra companion, even though it’s very small.”The discovery of 2020 XL5 as earth’s Trojan horse confirms that 2010 TK7 is not a rare exception, and there may be many more,””Toni Santana-Ros (ICCUB at the University of Barcelona (IEEC-UB)), lead author of the study and researcher at the University of Alicante and The Institute of Cosmic Sciences, told Space.com.”This encourages us to continue to strengthen our investigative strategy to find (if there were) the first proto-Earth Trojan horse.”This visualization shows the Earth-sun Lagrange point.Astronomers discovered 2020 XL5 using the Pan-StarRS 1 Survey telescope in Hawaii in December 2020 and added it to the International Astronomical Union’s Minor Planet Center database.Amateur astronomer Tony Dunn went on to calculate the object’s trajectory using NASA’s publicly available JPL-Horizon software and found it orbiting L4, the fourth Lagrange point between Earth and the sun, the region of gravitational balance around our planet and stars.2010 TK7, the first confirmed Trojan asteroid on Earth, is also at L4.”Preliminary results suggest it is in a Trojan orbit around our Lagrange point L4,” Dunn told Space.com.”Its orbit was very uncertain at the time, so I did a more careful analysis and simulated 100 clones with similar orbits.Each clone exhibits Trojan behavior.”But at the time, 2020 XL5’s orbit around the Sun wasn’t fully understood, so it wasn’t clear whether the object was just a nearby space rock passing through Earth’s orbit, or whether it could be a true Earth-Trojan asteroid.To confirm if it was an Earth Trojan asteroid, a team led by Santana-Ros observed the object using Chile’s SOAR (Southern Astrophysical Research) telescope, Arizona’s Lowell Discovery Telescope and the European Space Agency’s Optical Earth station.Tenerife in the Canary Islands.These are very challenging observations, requiring the telescope to track correctly within its minimum altitude constraints, as the object is very low on the western horizon at dawn.Santana-ros echoes how difficult it is to make these observations from Earth.For astronomers, pointing to L4 and L5 of the sun-Earth system on our planet is a pain!Any asteroids orbiting these points will only be visible above the horizon for a short time near dusk at very low altitudes.This visualization shows Earth’s Trojan asteroid 2020 XL5.To enhance their observations, the team also considered SOAR archival data to try to get a complete picture of the object and its orbit.In all, the team used about a decade of observations and data, according to NOIRLab’s statement.The team concluded that 2020 XL5 is, as originally suspected, an Earth-Trojan asteroid.They also found that the object was also likely a C-type asteroid, the most common type of asteroid in the solar system that is carbon-rich and dark.”The SOAR data enabled us to perform the first photometric analysis of the object, revealing that 2020 XL5 is most likely a C-type asteroid,” Santana-Ros said in the same statement.The study also showed that the object was much larger than the first Earth-trojan asteroid discovered.At about 0.73 miles (1.2 kilometers) wide, the 2020 XL5 is nearly three times as wide as the 2010 TK7, which is just 0.25 miles (0.4 kilometers) wide.The team also found that 2020 XL5 won’t be Earth’s Trojan asteroid forever.While it will remain in its current position for about 4,000 years, it will eventually escape its gravity-affected position, the statement said.We are fully confident that 2020 XL5 will continue to operate near L4 for at least 3500 years.Briceno noted in the statement that there could be more to come from this discovery, and the future could see humans set foot on these types of asteroids.”If we can find more Earth Trojans, and if some of them can have lower inclination orbits, then they could be cheaper than our moon,” Briseno said.”As such, they could be ideal bases for deep exploration of the solar system and possibly even a source of resources.”But whether or not we’ve ever sent humans to walk on them, NASA did launch the robotic Lucy Asteroid mission in 2021 to study Jupiter’s Trojan asteroids, and studying them could help us better understand the universe as a whole.Trojan asteroids like XL5 “can give us information about the formation of their host planets and, in turn, better understand the keys to the evolution of the solar system by adding constraints to their evolution models,” Santana-Ros told Space.com.”We’ve been studying the original Jupiter Trojan Horses for several years now, and we’ll soon have the opportunity to study them through field observations made by NASA’s space mission Lucy.”