What precious near-Earth asteroids are there around the earth?

Early astronomers thought asteroids were planets. It was not until 1851, when the number of these asteroids reached 23, that astronomers began to use the word "asteroid" to refer to them. A small celestial body. In 2006, the International Astronomical Union (IAU) added the dwarf planet classification to celestial bodies orbiting the sun, classifying several large-mass Ceres, Haumea, Makemake, and Eris as dwarf planets. As of March 6, 2017, MPC has confirmed 729,740 asteroids, including 483,390 numbered asteroids, 242,391 unnumbered asteroids, 3,959 comets, and 15,422 near-Earth asteroids. pellets.

There are three types of asteroid belts in the solar system: one is the asteroid belt that exists between Mars and Jupiter; the other is the Trojan group of asteroids that exist in the orbit of Jupiter; the third is the asteroid belt that exists between Mars and Jupiter; A group of Apollo asteroids that cross Earth's orbit. Humanity’s research on asteroids is mainly focused on their structure, composition and orbit. Considering that humans may have plans for interstellar immigration in the future, larger and more stable asteroids will most likely be used as interstellar immigrants. Used as a springboard relay station, it may also be developed as a mineral when resources are scarce in the future.

However, for now, it is not realistic enough for humans to capture asteroids and bring them to the earth. Of course, human beings still have confidence. For example, NASA once expressed its hope to capture an asteroid in lunar orbit for research in 2020. However, due to funding constraints, the plan did not go as smoothly as people imagined. In NASA's "Near-Earth Object Human Space Flight Target List" (NHATS list), there is an asteroid 2011UW158. It is said that this asteroid is worth about 5.4 trillion US dollars.

Of course, there are still many valuable asteroids, such as the M-class asteroid 16 Psyche (meaning "soul" in Greek, named "Psyche" in Chinese astronomy) "). This is one of many asteroids in the asteroid belt. It is about 230 million miles away from the Earth and has a diameter of 252 kilometers. A little different from other asteroids, Psyche seems to be composed entirely of iron and nickel. The composition is similar to that of the earth's core. Scientists estimate that it contains approximately 5 billion tons of iron, 5000 trillion tons of nickel, and hundreds of millions of tons of other rare metal substances.