An international team of planetary scientists led by astronomers at the AOP has found a trailing asteroid. Mars with composition very similar to the Moon. The asteroid can be an ancient piece of debris, resulting from the giant effects that form the Moon and other rocky planets in our solar system such as Mars and Earth. The research is published in the journal Icarus, also has implications for the search for primitive objects related to our planet.
A Trojan is a type of asteroid that follows the planets in their orbit when a flock of sheep can follow a shepherd, trapped in a 60-degree “safe haven” of gravity up front and forward. after the planet (Figure 1). They are of great interest to scientists because they represent matter left over from the formation and early evolution of the solar system. Those several thousand trojans exist along the orbit of the giant planet Jupiter. Closer to the sun, astronomers have so far discovered only a handful of Mars Trojans, the next planet to Earth.
Where did such an unusual object come from? One possibility is that 101429 is just another asteroid, perhaps similar to conventional chondrite meteorites, acquiring its moon-like appearance through repeated exposure to solar radiation, a process is called space weathering.
Also, the asteroid may look like the Moon because it comes from the Moon. Explained Dr. Apostolos Christou, AOP astronomer and lead author of the paper: “The early solar system was very different from where we see it today. The space between newly formed planets is filled with debris and collisions is normal. Large asteroids – we call them these planets – have been constantly hitting the Moon and other planets. A debris from such a collision could have reached Mars’ orbit while the planet was still forming and trapped in its Troy clouds.
The third scenario, and perhaps more likely, is the object coming from Mars itself. As Dr. Christou points out, “The shape of the 101429 spectrum tells us that it is rich in pyroxene, a mineral found in the outer or crust of planet-sized objects. Mars, like the Moon and Earth, has been affected by effects early in its history, one of which is responsible for the creation of the giant Borealis basin, a crater as wide as the planet itself. this. Such a huge impact could easily bring 101429 on the way to the planet’s Lagrangian L5 point ”. Indeed, Martian origin was proposed several years ago to the Troy siblings of 101429, a group of Trojans collectively known as the Eureka family (Figure 1). These asteroids also have an unusual composition, but while 101429 is rich in pyroxene, these Eureka asteroids are primarily olivine, a mineral found deep in the planet’s mantle.
101429 and its brethren also have something to teach us about finding Earth Trojans, if they exist. The group’s previous research has shown that solar radiation causes debris, in the form of boulders or blocks the size of city blocks, from these asteroids to slowly leak out of Trojan’s clouds. Mars. If Earth’s Trojans are anything like that of Mars, then the same mechanism that would act as a source of small asteroids near Earth would stand out for their uncommon composition.
Finding these objects could become the work of the Vera C. Rubin Observatory, which is poised to begin the most ambitious survey of the solar system to date. Rubin is expected to discover 10 times more asteroids than currently and together with the GAIA satellite that has surveyed the sky from the Earth-Sun Lagrange point L2, can provide us with The best short-term prospects for tracking fragments of the Trojan Earth Companion.
See: “Composition and origin of the Mars L5 Trojan asteroid: Spectroscopic insights” by Apostolos A. Christou,
Galin Borisov. Aldo Dell’Oro. Alberto Cellino and Maxime Devogèle, August 1, 2020, Icarus.
DOI: 10.1016 / j.icarus.2020.113994
Acknowledgments: Funding and facilities to support this work were provided by the UK Science and Technology Facility Council, Northern Ireland Department of Communities and THAT, European Astronomical Research Organization in the Southern Hemisphere.