Astronomers have revealed the most detailed map of the metallic soul of an asteroid to date

Astronomers have revealed the most detailed map of the metallic soul of an asteroid to date

If you want to do a forensic study of the solar system, you can go to the main asteroid site between the belt of Mars and Jupiter. This is where ancient rocks from the early days of the solar system can be found. Outside, in the empty cold of space, away from the sun, asteroids are unaffected by the climate of space.

Astronomers sometimes refer to asteroids, and their fragments of meteorites falling to Earth, as time capsules because of the evidence they have.

The asteroid Psyche is especially interesting and NASA is sending a mission to investigate the unusual piece of rock.

Prior to this mission, a team of researchers combined Psyche’s observations of a series of telescopes and projected a map of the asteroid’s surface.

Astronomers divide asteroids into three categories. Carbonic or type C asteroids are the most common type. They make up about 75% of known asteroids and contain large amounts of carbon. Carbon makes them dark and has a low albedo.

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

Metal or M-type asteroids are the rarest of all asteroids and account for 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 Earth. M-type meteorites were one of the oldest sources of iron in human history.

Psyche (16 Psyche) is an M-type asteroid. It is also called a dwarf planet because it is about 220 kilometers (140 miles) in diameter. It is known as the 16th Psyche because it was the 16th smallest planet discovered. (Major asteroids such as Psyche are also known as minor planets.)

Astronomers have revealed the most detailed map of the metallic soul of an asteroid to date(NASA / JPL-Caltech / Arizona State University)

Psyche is sometimes called the “gold mine asteroid” because of the rich iron and nickel it contains. Although of course, no one thinks they are rich in gold.

Psyche’s images don’t tell us much. The VLT of the European Southern Observatory took some photographs of the asteroid, but did not reveal any details.

The story of Psyche is a story of uncertainty. For a long time, astronomers thought it was the exposed iron core of a much larger object. In this case, a strong shock or a series of shocks stripped the bark and mantle of the body.

The largest object was completely discernible and measured about 500 kilometers (310 miles) in diameter. With the bark and mantle gone, only the iron-rich core remained.

This idea has not received much attention over time, and astronomers have continued to notice it. Evidence showed that it was not dense enough to be solid and probably porous iron.

Other researchers have suggested that Psyche was somehow disrupted and then reconstituted as a mixture of minerals and silicates. A study has indicated that Psyche is not as rich in minerals as previously thought and more so than a pile of rubble. In this scenario, collisions with the most common type C asteroids deposited a layer of carbon and other materials on the surface of Psyche.

The strangest idea behind the origins of Psyche is the volcanic notion of iron. A 2019 study provided evidence that Saeki was once a melting point. In this scenario, the outer layers cooled and formed stress cracks, and the floating molten core erupted like iron volcanoes.

The only way to know for sure what Psyche is is to look at it. This is what NASA does.

The mission is called Psyche and is scheduled to be launched sometime in the fall of 2022. The spacecraft will be based on solar and electric propulsion and a gravitational maneuver with Mars to reach Psyche in 2026.

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

Illustration 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 created a new map of Psyche’s surface to help prepare for the mission.

The map is in a research paper published in Journal of Geophysical Research: Planets. The address is The Heterogeneous Surface of the Psychic Asteroid (16), and the lead author is Saverio Cambioni of MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).

“The surface of Psyche is very heterogeneous,” Cambioni said in a press release. “It’s a sophisticated surface, and these maps confirm that metal-rich asteroids are intriguing and mysterious worlds. It’s another reason to expect Psyche’s asteroid mission.”

In this study, the authors used Gran Grupo Atacama Millimeter / Meter (ALMA) to better view 16 media. ALMA is a radio telescope consisting of 66 high resolution antennas. Separate antennas act together as a high-resolution interferometer.

ALMA operates with temperature-sensitive wavelengths and some electrical properties of the materials on the surface of Psyche.

“The signals from ALMA’s antennas can be combined into an artificial signal equivalent to a telescope with a diameter of 16 kilometers (10 miles),” said co-author Catherine de Clare, an 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, which is the time it takes for a substance to reach room temperature. Higher thermal inertia means it takes longer.

The second is the dielectric constant. The dielectric constant describes how materials conduct heat, electricity, or sound. A material with a low dielectric constant malfunctions and is a good insulator and vice versa.

The researchers took ALMA’s observations of thermal inertia and dielectric constant and conducted hundreds of simulations to see what combinations of materials could explain them. “We did these simulations region by region to be able to identify differences in surface properties,” Cambioni Diz said.

Pure iron has an infinite dielectric constant. By measuring the Psyche dielectric constant, researchers can map the surface and identify the areas richest in iron. Iron also has a high thermal inertia because it is very dense.

Thus, the combination of measures of thermal inertia and dielectric constant gives a good idea of ​​the surface regions present in Psyche that are rich in iron and other metals.

Researchers call a peculiar feature of Bravo Golf Psyche. This region has a systematically lower thermal inertia than mountainous regions. Bravo Golf District is a depression just to the right of the main meridian of the asteroid in the image below.

Why does a low altitude region have less thermal inertia? Other studies show that the area is also bright with radar. Why that? The researchers presented three possibilities.

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

“Ponds of fine-grained material have been seen in small asteroids, their gravity is low enough for the shocks to shake the surface and cause finer material to accumulate,” said Campione He. “But Psyche is a big body, so if fine-grained material accumulates 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 fractures can also make the lowlands more porous.

The third hypothesis is that the lowlands contain more silicate-rich materials than the highlands, which gives them a lower dielectric constant than some areas of the highlands. The idea is that the Bravo-Golf depression could have been formed by the impact of a silicate-rich collider that left a silicate-rich remnant.

Overall, the study showed that the surface of 16 Psyche is 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 greatly in different regions.

It also indicates that the asteroid may be the nucleus of the remains of a different body that lost its long-ago cover and crust.

“In conclusion, we provide evidence that Psyche is a mineral-rich asteroid with a heterogeneous surface, which has minerals and silicates, and appears to have evolved by impact,” the authors said. deduce.

Simone Marchi is a scientist at the Southwest Research Institute and an associate researcher on NASA’s Psyche mission. Marchi did not participate in the study, but spoke of its importance in a press release. “These data show that the surface of Psyche is heterogeneous, with marked differences in composition. A major goal of Psyche’s mission is to study the composition of the asteroid’s surface using gamma rays, a neutron spectrometer and an image in The potential presence of compositional variations is something that the psychology team is eager to study.

It is up to NASA’s Psyche mission to confirm these findings more rigorously.

But sending a spaceship to Psyche to understand it in more detail is more than Psyche itself.

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

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

People sometimes refer to Psyche as a gold mine asteroid because it is rich in minerals. Any object of its size would contain an enormous amount of iron, although it is likely that this value will not be reached or achieved soon.

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

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

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