Scientists discover yet another asteroid orbiting Earth

Our planet has a celestial lookout orbiting the path around the Sun, and it is only the second Trojan asteroid from Earth ever discovered.

A study detailing the discovery of Earth’s Trojan asteroid was published in the journal Nature Communications. Researchers observed the object, called 2020 XL5, using the Southern Astrophysical Research Telescope at (SOAR) in Chile.

“Trojans are objects that share an orbit with a planet, clustered around one of two special areas gravitationally balanced along the planet’s orbit, known as Lagrange points,” said study co-author Cesar Briceño, scientist at the SOAR telescope. at the Cerro Tololo Inter-American Observatory, in a statement.

Lagrange points are regions of space where the gravitational pull of the Sun and one of the planets is balanced, said the study’s lead author, Toni Santana-Ros, a researcher at the University of Alicante and the Institute of Cosmos Sciences at the University of Barcelona. .

The stable orbit of Earth’s Trojan asteroids makes them ideal for flybys of future space missions.

“If we are able to discover more terrestrial Trojans, and if some of them can have orbits with lower inclinations, they could become cheaper to reach than our Moon,” Briceño said. “Thus, they could become ideal bases for advanced exploration of the Solar System, or they could even be a source of resources.”

Trojan asteroids, named after Greek mythology, have been found orbiting the Sun along the same path as planets like Jupiter, Venus, Mars, Uranus and Neptune.

Jupiter has more than five thousand known Trojan asteroids that run in front of and behind the giant planet. NASA’s newly launched Lucy mission will be the first to explore some of Jupiter’s Trojans on its ambitious 12-year journey.

This is also the larger of Earth’s two Trojan asteroids so far, measuring around 1.2 kilometers in diameter. The first, 2010 TK7, was found over a decade ago and is about three times smaller.

Astronomers initially spotted the newly discovered asteroid Trojan on December 12, 2020, using the Pan-STARRS 1 survey telescope in Hawaii, and followed up with observations from other telescopes.

At first, they thought it was just a near-Earth body crossing our planet’s orbit, but the SOAR data were compared with previous observations captured by the Víctor M. Blanco 4-meter Telescope in Chile, between 2012 and 2019. .

Nearly a decade of data has helped scientists refine the object’s orbit to confirm that it is a Trojan asteroid.

The space rock will maintain its current orbit for the next four thousand years before gravity is likely to send it on a journey through space or into a highly elliptical orbit around the Sun.

The researchers also determined that it is a C-type asteroid that contains a lot of carbon, making it the most common type of asteroid found in our Solar System.

It is possible that this object originated from the main asteroid belt between Mars and Jupiter, but was ejected due to Jupiter’s enormous gravitational influence. But more research is needed to determine the origin of this body.

discovery challenges

Scientists believe there are likely many more Earth Trojan asteroids to discover, but they are incredibly difficult to detect.

Trojan asteroids are in orbits that place them in front of or behind a planet as it orbits the Sun, and they appear close to our star in our sky if we observe them from Earth.

Observations of Trojan asteroids can only be performed very close to sunrise or sunset with telescopes pointed close to the horizon.

This setup means that telescopes need to peer through the thickest part of Earth’s atmosphere. The SOAR telescope was able to point 16º above the horizon.

“These were very challenging observations, requiring the telescope to correctly track its lower elevation threshold, as the object was very low on the western horizon at dawn,” Briceño said.

As more and more satellite constellations are launched, this could impact astronomers trying to observe objects just above the horizon.

Finding more Trojan asteroids from Earth could pave the way for research into the early days of our Solar System.

“Asteroids are time capsules from the early days of our Solar System and can teach us a lot about the era of planet formation,” Santana-Ros said.

“Terrestrial Trojans are particularly interesting as they may be leftover material from the formation of the Earth. Finding an Earth Trojan made from material left over from Earth’s formation would be incredibly useful in unlocking many secrets of the early Solar System.”