Astronomers reveal most detailed map of asteroid’s metal soul to date

Astronomers reveal most detailed map of asteroid’s metal soul to date

If you want to do forensic research on the solar system, you can go to the major asteroid sites between the Mars belt and Jupiter. Here you can find ancient rocks from the early days of the solar system. In cold space away from the sun, asteroids are immune to space weather.

Astronomers sometimes refer to asteroids and their falling meteorite fragments as time capsules because they have evidence.

The Psyche asteroid is particularly interesting, and NASA sent a mission to investigate this unusual rock.

Prior to the mission, a team of researchers combined observations obtained by Psyche from a range of telescopes and projected a map of the asteroid’s surface.

Astronomers divide asteroids into three categories. Carbonaceous or C-type asteroids are the most common type. They make up about 75 percent of known asteroids and contain large amounts of carbon. Carbon darkens them and they have low albedo.

Silica or S-type asteroids are the second most common type. They make up about 17 percent of known asteroids and are mostly composed of iron and magnesium silicate.

Metallic or M-type asteroids are the rarest of all asteroids, making up about 8% of all known asteroids. It appears to contain more minerals than other types of asteroids, and scientists believe it is the source of iron meteorites falling to the ground. M-type meteorites are one of the oldest sources of iron in human history.

Psyche (16 Psyche) is an M-type asteroid, which is also called a dwarf planet because of its diameter of about 220 kilometers (140 miles). It’s called 16 Psyche because it’s the 16th asteroid discovered. (Major asteroids like Psyche are also called asteroids.)

(NASA/JPL-Caltech/Arizona State University)

Psyche is sometimes called a “gold-mining asteroid” because of its abundance of iron and nickel. Of course, no one thought they were rich in gold.

Psyche’s visuals don’t tell us much. The European Southern Observatory’s VLT took some pictures of the asteroid, but didn’t reveal any details.

Psyche’s story is an uncertain one. For a long time, astronomers thought it was the bare iron core of a larger object. In this hypothesis, a strong collision or series of collisions stripped off the celestial body’s crust and mantle.

Larger objects are fully identifiable, measuring about 500 kilometers (310 miles) in diameter. As the crust and mantle disappeared, only the iron-rich core remained.

Over time, the idea didn’t receive much attention, and astronomers continued to notice it. There is evidence that it is not dense enough to be solid and possibly porous iron.

Other researchers believe that Psyche was somehow destroyed and then reconstituted into a mixture of minerals and silicates. A study has shown that Psyche is not as rich in minerals as thought, and not just a pile of rubble. In this case, a collision with the most common C-type asteroid deposited a layer of carbon and other materials on Psyche’s surface.

The strangest idea behind the origin of Psyche is the concept of iron volcanoes. A 2019 study provided evidence that Saeki was once a melting point. In this case, the outer layer cools and tension fractures form, and the floating nugget erupts like an iron volcano.

The only way to know for sure what Psyche is is to look at her. That’s what NASA does.

The mission, called Psyche, is scheduled to launch sometime in the fall of 2022. The spacecraft will rely on solar and electric propulsion and gravitational maneuvers with Mars to reach Psyche in 2026.

Studying the asteroid will take 21 months and will follow four separate orbital paths, each successive path closer than the last.

Schematic of the Psyche spacecraft near the asteroid Psyche. (NASA/JPL-Caltech/Arizona State University)

As it approaches the asteroid, it will focus on various scientific goals.

A team of researchers has created a new map of Psyche’s surface to help prepare for the mission.

The map was published in a research paper Journal of Geophysical Research: Planets. The address is “Heterogeneous Surfaces of Psionic Asteroids (16),” lead author Saverio Cambioni of MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS).

“Psyche’s surface is very different,” Cambioni said in the release. “It’s a complex surface, and these maps confirm that metal-rich asteroids are fascinating and mysterious worlds. This is another reason to look forward to Psyche’s asteroid mission.”

In this study, the authors used the Grande Grupo Atacama mm/m (ALMA) to better view 16 media. ALMA is a radio telescope consisting of 66 high-resolution antennas. The separate antennas together act as a high-resolution interferometer.

ALMA operates using temperature-sensitive wavelengths and some electrical properties of the Psyche surface material.

“The signals from the ALMA antenna can be combined into an artificial signal equivalent to a telescope 16 kilometers (10 miles) in diameter,” said co-author Catherine DeClair, assistant professor of planetary science and astronomy at Caltech. “The bigger the telescope, the higher the resolution.”

The new map is based on two types of measurements. One is thermal inertia, the time it takes for a substance to reach room temperature. Higher thermal inertia means longer time.

The second is the dielectric constant. The dielectric constant describes the ability of a material to conduct heat, electricity or sound. Materials with low dielectric constants perform poorly and are good insulators, and vice versa.

The researchers used ALMA to run hundreds of simulations of the thermal inertia and dielectric constant observations to see which material combinations could explain them. “We performed region-by-region simulations so that we could identify differences in surface properties,” Cambioni Diz said.

Pure iron has an infinite dielectric constant. By measuring Psyche’s dielectric constant, the researchers could map the surface and identify the areas with the highest iron content. Iron also has a high thermal inertia because it is very dense.

Therefore, combining measurements of thermal inertia and permittivity can provide a good understanding of the iron and other metal-rich surface regions in Psyche.

The researchers call it a special feature of Bravo Golf Psyche. Thermal inertia in this region is systematically low compared to mountainous regions. Bravo Golf is a depression to the right of the asteroid’s prime meridian in the image below.

Why is thermal inertia less at lower altitudes? Other studies have shown that radar in the area is also bright. why is that? The researchers propose three possibilities.

The lowlands may be rich in minerals, but are covered with thin, porous craters that reduce their thermal inertia compared to the highlands covered with rough regolith. Thermal inertia increases with particle size. In this case, fine regolith builds up in the lowlands.

“Pumps of fine-grained material have been seen on small asteroids, and their gravity is low enough to shake the surface and cause the collection of finer material,” Campione He said. “But Psyche is gross, so if fine-grained material builds up at the bottom of the depression, that’s pretty interesting and mysterious.”

The second hypothesis is that the surface material covering the lowlands is more porous than the highlands. Thermal inertia decreases with increasing rock porosity. Impact cracks also make the lowlands more porous.

The third hypothesis is that the lowlands contain more silicate-rich material than the highlands, making them lower in dielectric constant than some areas of the highlands. The idea is that the Bravo-Golf depression may have been formed by the impact of a silicate-rich collider, leaving behind a silicate-rich residue.

Overall, the study showed that the surface of 16 Psyche was covered with a wide variety of materials. It also adds to other evidence that the asteroid is rich in minerals, although the abundance of minerals and silicates varies widely across regions.

It also suggests that the asteroid may be the core of a unique celestial remnant that lost its cover and outer shell long ago.

“Taken together, we provide evidence that Psyche is a mineral-rich asteroid with an uneven surface, presenting minerals and silicates, and appears to have evolved by impact,” the authors said. deduct.

Simone Marchi is a scientist at the Southwest Research Institute and a researcher on NASA’s Psyche mission. Marchi was not involved in the research, but stressed its importance in the press release. “These data suggest that Psyche’s surface is heterogeneous, with significant differences in composition. The primary goal of the Psyche mission is to study the composition of the asteroid’s surface using gamma rays, neutron spectrometers and color imagers. The potential for compositional variation is Something that psychology teams are eager to study.

NASA’s Psyche mission will more rigorously confirm these findings.

But it’s not just Psyche herself that sends a spaceship to Psyche to learn more about her.

If Psyche is the remnant core of a unique rocky planet, it would reveal something about our planet and how different objects formed. Will it contain some of the same light elements we expect to find in Earth’s core? The core is not dense enough to be pure iron and nickel. Scientists think it contains lighter elements such as sulfur, silicon, oxygen, carbon and hydrogen.

The Psyche mission will also determine whether asteroids formed under oxidative conditions contracted more or more than Earth’s core. This will tell us more about the solar nebula and protoplanetary disk.

Psyche is sometimes referred to as a gold-mining asteroid because it is rich in minerals. Anything the size of it will contain a lot of iron, although this value may not be reached or reached anytime soon.

But if knowledge is as valuable as iron, 16 Psyches could still be a gold mine.

This article was originally published by Universe Today. Read the original text.

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