From childhood, we learn the elementary truths about the structure of the Universe: all planets are round, there is nothing in space, the sun is burning. And yet, this is all not true. No wonder the new Minister of Education and Science Olga Vasilyeva recently announced that it is necessary to return astronomy lessons to school. The editors of Medialeaks fully support this initiative and invites readers to update their ideas about the planets and stars.
1. The earth is an even ball
The actual shape of the Earth is slightly different from the globe from the store. Many people know that our planet is slightly flattened from the poles. But besides this, different points of the earth's surface are removed from the center of the core at different distances. It's not just the relief, it's just that the Earth is uneven. For clarity, use such a slightly exaggerated illustration.
Closer to the equator, the planet generally has a kind of protrusion. Therefore, for example, the point on the earth's surface farthest from the center of the planet is not Everest (8848 m), but the Chimborazo volcano (6268 m) - its peak is 2.5 km further. This is not visible on images from space, since the deviation from the ideal ball is no more than 0.5% of the radius, in addition, the atmosphere smoothes out the imperfections in the appearance of our beloved planet. The correct name for the shape of the Earth is geoid.
2. The sun is burning
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We used to think that the Sun is a huge ball of fire, so it seems to us that it is burning, there is a flame on its surface. Combustion is actually a chemical reaction that requires an oxidizer and a fuel, an atmosphere. (By the way, this is why explosions in outer space are practically impossible).
The sun is a huge piece of plasma in a state of thermonuclear reaction; it does not burn, but glows, emitting a stream of photons and charged particles. That is, the Sun is not fire, it is a large and very, very warm light.
3. The Earth makes a revolution around its axis in exactly 24 hours
It often seems that some days pass faster, others more slowly. Oddly enough, this is true. A sunny day, that is, the time it takes the Sun to return to the same position in the sky, varies within plus or minus about 8 minutes at different times of the year in different parts of the planet. This is due to the fact that the linear velocity of motion and the angular velocity of the Earth's rotation around the Sun constantly change as it moves along an elliptical orbit. The day is either slightly increased or slightly decreased.
In addition to solar, there is also a sidereal day - the time during which the Earth makes one revolution around its axis in relation to distant stars. They are more constant, their duration is 23 hours 56 minutes 04 seconds.
4. Full weightlessness in orbit
It is generally accepted that the cosmonaut on the space station is in a state of complete weightlessness and his weight is zero. Yes, the influence of the Earth's gravity at an altitude of 100-200 km from its surface is less noticeable, but it remains just as powerful: that is why the ISS and the people in it remain in orbit, and do not fly away in a straight line into open space.
In simple terms, both the station and the astronauts in it are in endless free fall (only they do not fall down, but forward), and the very rotation of the station around the planet supports the hover. It would be more correct to call it microgravity. A state close to complete weightlessness can be experienced only outside the Earth's gravitational field.
5. Instant death in space without a spacesuit
Oddly enough, for a person who fell out of the hatch of a spaceship without a spacesuit, death is not so inevitable. It will not turn into an icicle: yes, the temperature in open space is -270 ° C, but heat exchange in a vacuum is impossible, so the body, on the contrary, will begin to heat up. Internal pressure is also not enough to blow up a person from the inside.
The main danger is explosive decompression: gas bubbles in the blood will begin to expand, but in theory this can be survived. In addition, in space conditions there is not enough pressure to maintain a liquid state of matter, therefore, water will begin to evaporate very quickly from the mucous membranes of the body (tongue, eyes, lungs). In earth orbit, under direct sunlight, instant burns of unprotected skin areas are inevitable (by the way, the temperature here will be like in a sauna - about 100 ° C). All this is very unpleasant, but not fatal. It is very important to be in space while exhaling (air retention will lead to barotrauma).
As a result, according to NASA scientists, under certain conditions there is a chance that 30-60 seconds of being in outer space will not cause damage to the human body that is incompatible with life. Death will eventually come precisely from suffocation.
6. The asteroid belt is a dangerous place for starships
Science fiction films have taught us that asteroid clusters are heaps of space debris that fly in close proximity to each other. On maps of the solar system, the Asteroid Belt also usually looks like a serious obstacle. Yes, in this place there is a very high density of celestial bodies, but only by cosmic standards: half-kilometer blocks fly at a distance of hundreds of thousands of kilometers from each other.
Humanity launched about a dozen probes that went beyond the orbit of Mars and flew to the orbit of Jupiter without the slightest problem. Impenetrable clusters of space rocks and rocks, such as those shown in Star Wars, can result from the collision of two massive celestial bodies. And then - not for long.
7. We see millions of stars
Until recently, the expression "myriad of stars" was nothing more than a rhetorical exaggeration. With the naked eye from the Earth in the clearest weather, one can see simultaneously no more than 2-3 thousand celestial bodies. In total in both hemispheres - about 6 thousand. But in photographs of modern telescopes, one can indeed find hundreds of millions, if not billions of stars (no one has counted yet).
The recently acquired Hubble Ultra Deep Field image captured about 10,000 galaxies, the most distant of which are approximately 13.5 billion light-years distant. According to scientists, these ultra-distant star clusters appeared “only” 400-800 million years after the Big Bang.
8. The stars are motionless
It is not the stars that move across the sky, but the Earth revolves - until the 18th century, scientists were sure that, with the exception of planets and comets, most of the celestial bodies remain motionless. However, over time, it was proved that all stars and galaxies are in motion without exception. If we went back several tens of millennia ago, we would not recognize the starry sky above our heads (like the moral law, by the way).
Of course, this happens slowly, but individual stars change their position in outer space so that it becomes noticeable after several years of observations. Bernard's star “flies” the fastest - its speed is 110 km / s. The galaxies are shifting too.
For example, the Andromeda Nebula, visible to the naked eye from Earth, approaches the Milky Way at a speed of about 140 km / s. In about 5 billion years we will collide.
9. The moon has a dark side
The Moon is always facing the Earth with one side, because its rotation around its own axis and around our planet is synchronized. However, this does not mean that the sun's rays never fall on the half invisible to us.
On a new moon, when the side facing the Earth is completely in shadow, the other side is fully illuminated. However, on a natural satellite of the Earth, day changes to night somewhat slower. A full lunar day lasts approximately two weeks.
10. Mercury is the hottest planet in the solar system
It is quite logical to assume that the planet closest to the Sun is also the hottest in our system. Also not true. The maximum temperature on the surface of Mercury is 427 ° C. This is less than Venus, which recorded a reading of 477 ° C. The second planet is almost 50 million km farther from the Sun than the first, but Venus has a dense atmosphere of carbon dioxide, which, due to the greenhouse effect, preserves and accumulates temperature, while Mercury has practically no atmosphere.
There is one more thing. Mercury makes a complete revolution around its axis in 58 Earth days. A two-month night cools the surface down to -173 ° C, that is, the average temperature at the equator of Mercury is about 300 ° C. And at the poles of the planet, which always remain in the shadows, there is even ice.
11. The solar system consists of nine planets
Since childhood, we used to think that the solar system has nine planets. Pluto was discovered in 1930, and for over 70 years it remained a full member of the planetary pantheon. However, after much debate, Pluto was downgraded in 2006 to the title of the largest dwarf planet in our system. The fact is that this celestial body does not correspond to one of the three definitions of a planet, according to which such an object must, with its mass, clear the vicinity of its orbit. Pluto's mass is only 7% of the combined weight of all Kuiper belt objects. For example, another planetoid from this area, Eris, is only 40 km smaller than Pluto in diameter, but noticeably heavier. For comparison, the mass of the Earth is 1.7 million times greater than that of all other bodies in the vicinity of its orbit. That is, there are still eight full-fledged planets in the solar system.
As a rule, only the estimated distance between such a planet and its star is known. Of the hundreds of exoplanets found that are within the habitable zone, potentially suitable for supporting Earth-like life, only a few could potentially turn out to be similar to our home planet.
13. Jupiter and Saturn - balls of gas
We all know that the largest planets of the solar system are gas giants, but this does not mean at all that once in the gravitational zone of these planets, the body will fall through them until it reaches a solid core.
Jupiter and Saturn are composed primarily of hydrogen and helium. Under the clouds, at a depth of several thousand km, a layer begins in which hydrogen, under the influence of monstrous pressure, gradually passes from a gaseous to a state of a liquid boiling metal. The temperature of this substance reaches 6 thousand ° C. Interestingly, Saturn emits into space 2.5 times more energy that the planet receives from the Sun, it is not yet clear why.
14. In the solar system, life can only exist on Earth
If something similar to life on Earth existed anywhere else in the solar system, we would notice it … Right? For example, the first organics appeared on Earth more than 4 billion years ago, but for another hundreds of millions of years no external observer would have seen any clear signs of life, and the first multicellular organisms appeared only after 3 billion years. In fact, besides Mars, there are at least two other places in our system where life may well exist: these are the satellites of Saturn - Titan and Enceladus.
Titan has a dense atmosphere, as well as seas, lakes and rivers - though not from water, but from liquid methane. But in 2010, scientists from NASA announced that they had found on this moon of Saturn signs of the possible existence of the simplest forms of life, instead of water and oxygen, using methane and hydrogen.
Enceladus is covered with a thick layer of ice, it would seem, what kind of life is there? However, under the surface at a depth of 30-40 km, according to planetary scientists, there is an ocean of liquid water about 10 km thick. The core of Enceladus is hot, and there may be hydrothermal vents in this ocean like the terrestrial "black smokers". According to one of the hypotheses, life on Earth appeared precisely due to this phenomenon, so why not the same thing happen on Enceladus. By the way, water in some places breaks through the ice and erupts outward in fountains up to 250 km high. Recent evidence confirms that this water contains organic compounds.
15. Space is empty
There is nothing in interplanetary and interstellar space, many are sure from childhood. In fact, the vacuum of space is not absolute: in microscopic quantities there are atoms and molecules, relic radiation that remained from the Big Bang, and cosmic rays, which contain ionized atomic nuclei and various subatomic particles.
Moreover, scientists recently suggested that the cosmic emptiness actually consists of matter that we cannot yet fix. Physicists have called this hypothetical phenomenon dark energy and dark matter. Presumably, our Universe is 76% dark energy, 22% dark matter, 3.6% interstellar gas. Our ordinary baryonic matter: stars, planets, and so on - this is only 0.4% of the total mass of the universe.
There is an assumption that it is the increase in the amount of dark energy that makes the universe expand. Sooner or later, this alternative entity, in theory, will tear the atoms of our reality into shreds of separate bosons and quarks. However, by that time, neither Olga Vasilyeva, nor the lessons of astronomy, nor mankind, nor the Earth, nor the Sun have existed for several billion years.
STAS ELISEEV
