The first real images of Iapetus! The surprising world of Saturn's moon! скачать в хорошем качестве

The first real images of Iapetus! The surprising world of Saturn's moon!

As you probably know, there are many wonders and mysteries of the universe in distant stars and galaxies. However, among them are some that we can observe without having to travel so far. There are several of these mysterious celestial bodies right here near us. For example, one of them is Iapetus, one of the most peculiar satellites in the Solar System. What makes this satellite so fascinating? This is Iapetus. Iapetus was the second satellite of Saturn to be discovered. It was in 1671, 16 years after the discovery of Titan. It was discovered by the great astronomer Cassini. Later, Cassini discovered three other satellites of Saturn called Rhea, Dione, and Tethys, but that is not the topic we will cover in this video. The diameter of Iapetus is approximately 1,491 kilometers. Among Saturn's numerous satellites, only Titan and Rhea are larger than it. Iapetus is quite far from Saturn and takes 79 days to complete one orbit. To this day, it is considered the 24th satellite, counting from those closest to Saturn. When satellites of other planets are discovered, it often seems at first that there is nothing particularly remarkable about them. However, subsequent investigations often reveal surprising properties. For example, it was not immediately known that there was an ocean beneath Europa's ice, that Titan had a complete hydrosphere of hydrocarbons, or that Triton had ice volcanoes. However, this was not the case with Iapetus. Cassini had already noticed that this satellite behaved in an unusual way. When Cassini discovered this satellite, it was already known that Jupiter had several satellites and that Saturn had one. Two Hemispheres As I mentioned before, the most striking feature of Iapetus is the large difference in brightness between its two hemispheres. The "leading side," that is, the part that coincides with the direction of its orbit, is the dark hemisphere. If we compare this satellite to a ship, the dark hemisphere would correspond to the bow. The bright hemisphere, or the "trailing side," would be the stern. The border between the two hemispheres is irregular and does not coincide with a perfect meridian. In other words, rather than resembling a "chocolate egg" split in half with a straight line, Iapetus is more like a "tennis ball" with a broken outline. Both poles of Iapetus are light, while in the "trailing" hemisphere, part of the equatorial region is dark. The light areas cover about 60% of Iapetus's surface and are larger than the dark ones. Furthermore, according to detailed images taken by the Cassini spacecraft, the border between light and dark is extraordinarily sharp. If, hypothetically, we could stand on the edge of the bright hemisphere, the dark area would begin just 30 meters away. There is no "intermediate zone" or "gray" section. There is only black and white; or, more precisely, white and a dark brown hue. Since Iapetus is an icy satellite, it is natural to assume that initially, its entire appearance was clear. The dark hemisphere is nothing more than a large patch of dust that has been deposited on the surface. The Great Wall Thanks to images taken by the Cassini spacecraft, it was confirmed that there is another peculiar geographical feature on the surface of Iapetus. Along the equator, a very high ridge extends, like a wall of ice, 13 kilometers high and more than 20 kilometers wide, surrounding the entire satellite. This wall extends into the equatorial region of both the light and dark hemispheres. It's like the Great Wall in "Game of Thrones," but its origin remains a mystery. One theory suggests that the interior of this moon is made of ice and that this ridge is a sort of "exit" that reaches the surface. However, how exactly this kind of "gap" formed is not well understood. Many icy moons have been discovered, but none exhibit anything similar. Perhaps Iapetus once rotated faster and its diameter was slightly larger. Over time, its rotation slowed down until it synchronized with its orbital period, as happens with many other moons, and Iapetus itself shrank. This is how this enormous wall-like "wrinkle" could have emerged. However, it is still unknown why something similar is not observed on other moons in the Solar System. Another theory suggests that this "wall" is the legacy of a "grandson moon" that once existed around Iapetus. Indeed, in theory, just as a planet orbiting a star can have satellites, a planetary satellite could have its own satellite.