Posted on May 16, 2022 74
1. Astronomy is the science of studying the universe.
2. It has been known to humanity since ancient times. Even representatives of ancient civilizations described the laws related to the location of the Moon, the Sun, and other celestial bodies and used them for practical purposes.
3. The study of the universe continues to this day. However, despite the many discoveries made, it continues to hold a great deal of mysterious and unexplored things that modern scientists cannot yet explain.
4. Observing the stars is like looking into the past, as we see light from stars that may no longer exist. Stars are very far away, so their light reaches Earth hundreds, thousands, or even millions of years later.
5. For example, the Pillars of Creation, which are part of the Eagle Nebula and are 7,000 light years away from Earth. These column-like clusters of dust and gas were first recorded by the Hubble telescope in 1995. But in fact they were destroyed about 6,000 years ago by an explosion from the birth of a supernova. So in real time, they are long gone.
6. Not all the bright lights seen in the night sky are stars. The closest to our planet are Proxima Centauri, Star Bernard, Sirius, and others. However, besides these, planets and comets are also visible.
7. The Sun is one of 220-400 billion stars in our galaxy.
8. The lowest temperature on the Moon is -164 degrees Celsius. And the highest temperature on our satellite is +117 degrees Celsius.
9. What we used to call “falling star” is actually the remnants of a comet or cosmic dust. When they enter the atmosphere, they begin to actively burn, producing bright light.
10. Ceres is the largest asteroid, measuring 940 kilometers in diameter.
URAN IN COSMOS
11. The planet Uranus is visible from Earth with the naked eye (if atmospheric conditions are good, on a moonless night).
12. On January 7, 1610, Galileo Galilei directed the telescope he built into the sky for the first time in human history.
13. The nearest star to the solar system, Proxima Centauri, is 4.2 light-years away.
14. The Moon is 400 times smaller than the Sun in size, but also 400 times closer to the Earth.
15. Mountains on Mars reach a height of 20-25 kilometers. And Mount Maxwell on Venus reaches a height of 11 kilometers.
16. The closest planet to the Sun is Mercury. It is the smallest planet in the solar system - the diameter of its equator is almost 3 times less than the Earth’s. It is clearly visible in the night sky.
17. Although Mercury is the closest to the red-hot star, its surface can cool down to -193C. This is because Mercury has no dense atmosphere to trap heat. During the day, the side that faces the Sun heats to 427C. But once it moves into the shade, the temperature drops precipitously.
18. The planets of the solar system are clearly visible at night. The sun’s rays are reflected from their surface, which is why they become so bright. With the naked eye in clear weather, you can see Venus (the brightest point in the sky), Mars (has a characteristic reddish hue), Mercury, Saturn and Jupiter.
19. In the sky, they appear quite large, larger than many stars. But in fact, this optical deception is explained by the different distance-the planets are much closer to the Earth than the stars.
20. About 200 thousand meteorites fall to Earth every day.
21. The hottest planet in the solar system is Venus. The second planet from the Sun can get hotter than 470 C. The reason for this is a very dense atmosphere capable of accumulating the heat received.
22. Venus’ atmosphere is 92 times denser than Earth’s, and the pressure on the planet’s surface is comparable to the pressure when sinking into the Earth’s ocean by 1 kilometer.
23. The density of the atmosphere prevents a detailed study of the planet from space with probes or radio telescopes. Landing of an automatic interplanetary station on the surface is possible, but it is associated with great difficulties and there is a high probability of failure of this mission.
24. The coldest planet is Uranus. Just as Mercury, the closest planet to the Sun, is not the hottest, so Neptune is the farthest planet, but not the coldest. Neptune is 4.5 billion kilometers from the Sun, while Uranus is only 2.8 billion kilometers away.
25. But Uranus is significantly colder than Neptune. The average temperature on the “surface” of Uranus is -197C, and can drop to -226C. The planet gives off less heat than it absorbs. Unlike its “neighbors,” Uranus has a cold core that does not give off much energy.
26. Interestingly, the Moon could be a cosmic source of water, as it contains much more H2O than previously assumed.
27. In studying the surface of the Earth’s satellite, it was discovered that water can be extracted from pyroclastic deposits. These are specific substances on the Moon, comprising volcanic glassy rocks that were formed during ancient eruptions.
28. The universe comprises at least two matters. First, it is baryonic matter (“ordinary” matter) comprising neutrons and protons, which can be measured by means. Baryonic matter includes galaxies and their constituents.
29. However, there are substances that cannot be seen or detected by conventional observational methods. They have a gravitational effect on baryonic matter, so their existence is beyond doubt. These substances are called “dark matter”. Together with dark energy, they make up 95% of all matter in the universe.
30. A beam of light from the star Deneb, which is part of the constellation Swan, traveled to us for 800 years.
THE MOON IN COSMOS
31. The highest mountain on the Moon is 11,500 meters high.
32. An interesting fact from astronomy is that the universe has an age. Einstein assumed the universe is eternal, and it makes no sense to speculate about its age.
33.However, in 1929, while observing various galaxies, it was discovered that they were moving away from each other and from the Milky Way. From this discovery, it was deduced that the universe was expanding. This phenomenon can be compared to the inflation of a balloon. If the Universe is expanding, then there must be a starting point for this expansion and an end to the process. Its age is finite and can be calculated.
34. The age of the Earth has been determined by experiments with radioactivity and is 4.5 billion years.
35.However, it is not possible to conduct similar experiments with distant galaxies. Therefore, scientists were guided by mathematical calculations based on radio telescope readings. According to current data, the Universe is about 13.7 billion years old. But this value is constantly being refined.
36. There are 200 to 400 billion stars in our galaxy, and planets orbit around each of them. Astronomers estimate that about every star is like the Sun.
37. Of these, about 22% have planets similar in size and location to Earth. They are in the so-called “habitable zone,” where water can be in a liquid state. This means that there are about 8.8 billion planets in the galaxy capable of supporting life (if you don’t consider the composition of their surface and atmosphere). So, there may be planets in the Milky Way on which life is theoretically possible.
38. There are billions of galaxies in the universe, forming clumps, layers, and chains separated by space.
39. The nearest Andromeda galaxy is 2.5 million light years away. Andromeda now looks like it did in the time of man’s distant ancestors, the Australopithecus.
40. On February 7, 2001, the SOHO orbiting observatory tracked the fall of a comet to the Sun.
SATURN IN SPACE
41. Saturn is 758 times the volume of the Earth, but it is so light that if it could be placed in an enormous aquarium with water, it would float in it.
42. A curious fact from astronomy is that space has an odor. After completing a spacewalk, many astronauts noted an unusual aroma in their spacesuits: from the smell of metal to steak overcooked on coals.
43. This is because of polycyclic aromatic hydrocarbons (PAHs) in space, which are produced by nuclear reactions during the dying of stars. PAHs are also released when gasoline, wood, and coal are burned. Therefore, meat on fire takes on a corresponding odor.
44. But these are not the only aromas that can be found in space. For example, the gas-dust cloud at the center of the Milky Way contains large amounts of ethyl form, a compound that gives the smell of raspberries.
45. Over the past 500 years, the mass of the Earth has increased by a billion tons because of cosmic matter, as tons of interplanetary dust reach the Earth each year.
EARTH IN SPACE
46. The Earth weighs approximately 600 trillion tons.
47. On Venus, a day is longer than a year.
48. Ceres is the first discovered asteroid. It was discovered by Giuseppe Piazzi of Palermo, Sicily, on January 1, 1801.
49. It takes 200 million years for the sun to travel around the center of the galaxy.
50. Currently, the sky is conventionally divided into 88 regions, the constellations.
51. The diameter of the Sun is about 109 times the diameter of the Earth.
52. Local supercluster of galaxies in Virgo comprises about 5 thousand galaxies combined in several clouds.
THE CONSTELLATION ALPHA CENTAURI
53. Seven stars are within 10 light years of us, and the nearest to us is the faint companion Proxima Centauri of the Alpha Centauri system.
54. The solar system is in one of the spiral arms of the Milky Way, comprising stars, gas, and dust. The local group includes three spiral galaxies: the Andromeda Galaxy (M31), the Milky Way, and M33.
55. The human eye can see up to 5,000 stars in the entire night sky.
56. A very interesting fact from astronomy is the merging of galaxies. The process of one or more galaxies colliding occurs when the distance between them is reduced. Also, some younger galaxies can engulf older galaxies.
57.The merging of galaxies has a significant effect on stars and dark matter. The orbits of stars change, which then form a complex system of orbits with disordered motion.
58.Active star formation can be observed in merging galaxies. It can reach values of thousands of solar masses per year. For comparison, in the Milky Way galaxy an average of two stars are formed.
59. Just as the Earth moves around the Sun, the Solar System rotates in its orbit around the center of the Milky Way. It takes approximately 230-250 million years to complete a complete revolution. Thus, when the Solar System was in its present position in its orbit last time, the first dinosaurs had only just emerged, and flowering plants should not emerge until 100 million years later.
60. Polaris, in the constellation Ursa Minor, is near the North Pole. As the Earth rotates, it remains stationary, so it is used for orientation in space - it constantly points to the North.
61. However, this will not always be the case. The fact is that the Earth’s axis moves slowly in a circle and has a 26,000-year rotation cycle. Therefore, at different times, the nearest stars to the North Pole replaced and continue to replace each other. So, in the days of ancient Egypt (about 3,000 years BC) the nearest star to the pole was Tuban of the constellation of the Dragon. And in 12,000 will be Vega from the constellation Lyra.
62. On the surface of Venus, the temperature reaches 430 degrees Celsius during the day.
63. In 1671, Isaac Newton presented a new type of telescope, the reflector, to the Royal Society.
64. A huge amount of debris has accumulated in Earth’s orbit in recent decades. Most of it comprises debris from satellites ever launched by humans. The debris varies in size from large to microscopic, but it moves through orbit at enormous speeds.
65. To date, there is no technology to clear space in orbit, but scientists are working on it. So far, the U.S. has developed a special system that tracks the movement of debris - the Space Surveillance Network (SSN). It helps to eliminate the collision of debris with satellites.