Using observations made with the Gran Telescopio Canarias (GTC), a study conducted by the Institute of Astronomy Medicine of the Canary Islands (IAC) and the Complutense University of Madrid (UCM) confirmed that the asteroid 2023 FW14, discovered last year, is accompanying the galaxy. red planet. In its journey around the Sun, it is ahead of Mars and in the same orbit.

This new member brings the number of Trojans accompanying Mars to 17. However, it differs in its orbit and chemical composition, which may indicate that it is a primitive captured asteroid. Results are published on: Astronomy and Astrophysics.

A team from the Canary Islands Institute of Astronomical Medicine (IAC) and the Universidad Complutense de Madrid (UCM) has observed and described the object 2023 FW14, a Trojan asteroid that shares orbit with Mars, for the first time. After Jupiter, the red planet has the most well-known Trojans, with a total of 17 Trojans according to this new definition.

Trojan asteroids are small objects in the Solar System that share a common orbit with the planet, occupying one of the fixed equilibrium points, called Lagrange points, 60° ahead (L).₄) and 60° behind (L₅) planets.

While most asteroids on Mars appear to have accompanied the planet since its formation, numerical results show that 2023 FW14 reached the Trojan orbit about a million years ago and could leave in about 10 million years. research

“While the orbital evolution of the 16 previously known Trojans showed long-term stability, the orbit of the new one is not,” explains Raúl de la Fuente Marcos, a researcher from the UCM Department of Earth Sciences and Astrophysics who led the study. . “There are two possibilities for its origin: The Trojan may have been part of 1999 UJ7, or it may have been captured in a population of near-Earth asteroids passing around Mars’ orbit.”

A spectrum obtained with the Gran Telescopio Canarias (GTCI) at the Roque de los Muchachos Observatory on the island of La Palma allowed researchers to determine the chemical composition of 2023 FW14, revealing new differences compared to the rest of the Martian Trojans.

“Although the spectrum of the 2023 FW14 obtained with GTC is slightly different from other L₄ Trojan 1999 UJ7 are asteroids of primitive type, unlike L, both belonging to the same composition group. ₅ Trojan. They are all rocky and rich in silicate,” says Julia de Leon, an IAC researcher and co-author of the paper.

The increase in the number of known Mars Trojans is allowing researchers to deepen their understanding of these objects, whose existence was predicted for the first time based on mathematical calculations. De la Fuente Marcos concludes: “Studying real Trojans, not just mathematically predicted ones, allows us to test the robustness of our theoretical models.”