Interesting Facts About Asteroids
Based on the topic of asteroids, Americans like to make films with a frightening storyline. The most famous movie - is "Armageddon" with Bruce Willis. But most viewers do not have the slightest idea about these space objects, what they are, where they come from, where and how they move. All this will help to understand interesting facts about asteroids.
1. Under the concept of the asteroids or small planets we can understand, celestial bodies with a body diameter of at least 30 meters fall. Bodies with smaller dimensions are called meteoroids.
2. The number of small planets in the solar system with a diameter of more than 1 km exceeds 1,900,000 pieces. To date, the astronomical database contains data on 670,000 such objects, of which only 420,000 are orbits, and the names have only 19,000 small celestial bodies. Their total number exceeds 30,000,000 pieces. The largest number of them is located in the so-called belt of asteroids, between the orbits of the planets Mars and Jupiter.
3. According to the official hypothesis, asteroids are not fragments of the destroyed Phaethon, but embryos of an unformed planet. This conclusion was reached on the basis of the fact that small planets have not the same age.
4. The largest asteroid is Ceres with a diameter of 950 km, which is 4 times smaller than the diameter of the Moon. Such huge dimensions give grounds to call Ceres a dwarf planet.
5. The second largest asteroid is Pallada (550 km in diameter), the third is Vesta (diameter 530 km), and the fourth is Gigei (diameter 407 km). Another 5 minor planets have dimmers up to 300 km, 30 - up to 200 km, 200 - up to 100 km.
6. There is a well-founded theory, according to which water and life on Earth are brought by asteroids. This idea is confirmed by the traces of H2O and complex hydrocarbons discovered on small planets.
7. The small planet Icarus in certain periods of motion approaches the Sun at a distance less than the planet Mercury.
8. The asteroid Vesta (the third largest) in some periods of rotation can be observed without using special equipment. Such a strong brightness of this small planet is caused by a high albedo (reflective ability).
9. The danger to the entire earth civilization can be represented by collisions with cosmic bodies with diameters from 3 km. Bodies with a size of 50 meters in a collision with the Earth can lead to significant economic damage.
10. The most dangerous at this time is the asteroid Apophis with a diameter of 300 meters. Its orbit passes in threatening proximity from the orbit of our planet. On January 9, 2013, it approached the Earth at 14 460 000 km. According to preliminary calculations, Apophis in 2029 will pass near our planet at a distance of only 38,600 km, ten times closer than the Moon. The next "dangerous" passage of Apophis will be the year 2036.
11. For 200 years of active astronomical observations, the closest passage from Earth was an asteroid with the designation 1998 QE2. The minimum distance from our planet was 5,000,000 km on 01 June 2013, which is 14 times the distance to the Moon (390,000 km).
12. The largest asteroid that collided with the Earth had a diameter of about 10 km. This event occurred 65,000,000 years ago. The trail from the fall can be seen today - this is the Gulf of Mexico off the coast of North America. That collision led to great cataclysms that killed more than half of the living beings of our planet.
13. Asteroids, in addition to different sizes, also have a different chemical composition. The large percent of small planets (about 75%) have a carbon structure; 17% - sand (silicate); more than 6% - metal.
In general, the composition of the asteroids is determined by how close they are to the Sun. The pressure of our nearest star and its heat tends to melt the ice that is near and blow away the elements that are lighter. There are many types of asteroids, but in accordance with NASA distinguish three of their types:
- “Dark C” (carbon) asteroids, which are in the majority in the outer belt. In their composition, they are similar to the Sun, with small admixtures of hydrogen, helium and other volatile elements.
- “Bright S” (silicate) asteroids in the inner belt. They, as a rule, consist of iron with impurities of its silicates and magnesium.
- “Bright M” (metallic) asteroids. They are in the middle of the belt of asteroids and mainly consist of iron.
14. In addition to the Asteroid belt, in the solar system, there are several more clusters of such celestial bodies. One is located beyond the orbit of Neptune and is called the “Kuiper belt”. It includes hundreds of objects with diameters from 100 to 800 km. The other is located halfway from the belt to the Kuiper belt and is called Centauri. There are other groups of small space bodies: Vulcanoids, near-Earth, crossing the orbit of Mars, Trojan, and Damocloids.
15. The most famous object of the Centaur class is the small planet Chiron. Its popularity was not only due to its size (diameter about 200 km) but also because it is often confused with a comet. After all, Chiron has the ability to periodically form a "tail", reminiscent of a comet.