For a long time in the solar system, Pluto was called the smallest planet. The situation changed in 2006 when it was classified as a dwarf. And although some scientists still disagree with this decision, Mercury is officially recognized as the smallest.
Mercury is the smallest planet in the solar system
Scientists note that the size of Mercury is only slightly larger than that of our Moon. The planet has a diameter of only 4879 km, for comparison, the diameter of our planet is 12,742 km, and the largest planet - Jupiter - 142984 km. Thus, Earth is 38% larger than Mercury in size, and Jupiter is 29.3 times larger.
The smallest planet in the solar system weighs 3.3 * 1023 kg. Relative to Earth, the mass of Mercury is 0.055. The volume of Mercury is 6.083 * 1010 km3 (0.056 of the earth's volume). If you imagine the Earth as a hollow ball, 20 Mercury could fit in it.
Mercury is a terrestrial planet that consists of metals and silicate materials. The structure looks like this:
- metal core;
- mantle;
- bark.
The radius of the core is quite large (1800 km), and it is 42% of the total volume of the planet. The thickness of the mantle is supposedly 500-700 km, and the crust is 100-300 km. The high content of metals in the bowels of Mercury explains the high average density - 5.43 g / cm³, which is not much less than that of the Earth.
The surface of Mercury resembles the lunar in its state. It is absolutely uniform, but at the same time it is covered with numerous craters. There is no erosion on the surface, which means that there is no significant atmosphere, only a very rarefied one. According to scientists, the atmospheric pressure on Mercury is 5 * 1011 times less than the pressure of the Earth's atmosphere.
Mercury - interesting facts
One of the features of Mercury is significant temperature drops. This is due to the fact that the planet is closest to the Sun. In the daytime, the surface warms up to 450 degrees, at night it drops to -170 degrees. At the same time, there is ice on the surface of Mercury in the depths of the craters, which can be brought by a comet and a meteorite or formed from water vapor.
If it were possible to stand on the surface of Mercury, we would be able to feel only 38% of Earth's gravity. Moreover, the gravity on the smallest planet is even higher than on Mars, which is associated with high density.
Mercury is called not only the smallest, but also the fastest planet in the solar system... 88 Earth days - that is how much Mercury needs to make a complete revolution around the Sun.
The planet's magnetic field is a very mysterious phenomenon, not fully understood. What is known for sure is the difference in the magnetic field at different poles: at the south it is more intense, at the north - weaker.
Previously, it was suggested that Mercury belongs to the planets that have a satellite. However, this theory was later refuted.
Studying the smallest planet is difficult enough not only because it is too close to the sun. Scientists joke that Mercury loves to "play hide and seek", constantly hiding behind the Sun. At the same time, Mercury is included in the list of planets that can be seen with the naked eye. In addition to him, this list includes Venus, Mars, Jupiter and Saturn.