Chapter 1815: Ceres

Chapter 1815 Ceres

It can be said that Ceres may be more famous than Vesta, Juno and Pallas. Anyone who has been to school should have heard of this asteroid.

After hearing what his son said, Zhao Zhongyao also said happily,'Let's go, let's set off for Ceres. '

After finishing speaking, Zhao Zhongyao drove the spaceship and flew towards Ceres.

From Pallas to Ceres, there are still hundreds of millions of kilometers away. However, for the extremely fast flying saucer spacecraft, this distance is nothing. The flying saucer spacecraft can fly to Ceres in less than an hour at the fastest speed.

During the flight to Ceres, Feifei wanted his father to explain to them the knowledge about this Ceres.

After all, this Ceres is too famous. It can be said that among all the asteroids in the solar system, the reputation of Ceres can definitely rank first.

Although everyone has heard of this asteroid, not many people know this asteroid very well. Everyone has just heard of this very large asteroid.

After hearing Feifei's words, Zhao Zhongyao said, "Okay, there are really endless topics about this Ceres, this asteroid." In fact, it is the most mysterious asteroid. First of all, he is no longer an asteroid now. Ceres is now classified as a dwarf planet. Because his size is too big among asteroids. But among the dwarf planets, it is the smallest. Therefore, Ceres is a very special asteroid between asteroids and dwarf planets. '

After hearing what Zhao Zhongyao said, Feifei said again, "Dad, do you know this Ceres very well, please explain to us more about this Ceres." '

After hearing what his son said, Zhao Zhongyao smiled and said, 'Okay, I will explain to you some knowledge about this Ceres in detail. '

Next, Zhao Zhongyao talked about some knowledge about Ceres.

Ceres is the smallest and only dwarf planet in the asteroid belt in the solar system. It was discovered by the Italian astronomer Piazzi and announced on January 1, 1801. In 2006, the International Astronomical Union redefined Ceres, once considered the largest known asteroid in the solar system, as a dwarf planet.

Ceres is likely to be a differentiated planet with a rocky core, and the mantle layer contains a large amount of ice-water substances, and a large amount of water-carrying minerals have been detected on the surface of the planet. It is preliminarily speculated that water accounts for 40% of the volume of Ceres. Ceres is also powered by solar energy, as it is only 2.8 AU from the sun, compared to Europa and Enceladus, which are farther away at 5.2 and 9 AU, respectively.

Ceres is located in the asteroid belt between the orbits of Mars and Jupiter, and previous studies have confirmed that there are large amounts of ice in its interior. Using the Herschel telescope, ESA reported in the journal Nature that for the first time water vapor has been detected on Ceres, coming from darker regions of the planet's surface. The amount of water vapor is not large, about 6 kilograms per second, but this discovery is of great significance for confirming that there is water on Ceres. The researchers speculate that there may be two specific reasons for the water vapor to emerge: one is that the ice on the surface of Ceres is rapidly heated by the sun's radiation, and the other is that Ceres still has energy inside. Scientists speculate that oceans may have liquid water.

The existence of life requires 3 basic conditions - liquid water, energy sources and certain chemical components (carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, etc.), and Ceres has certain advantages. "

The classification of Ceres has been changed many times, all due to disagreements among astronomers. John Bode believed that Ceres was the "missing planet" between Mars and Jupiter, 419 million km (2.8 au) from the sun. Ceres was given the symbol of a planet, and Ceres (along with Pallas, Juno, and Vesta) was listed as a planet in astronomy books for nearly half a century before more asteroids were discovered .

However, when other celestial bodies were discovered in the same range one after another, people gradually realized that Ceres was just one of many similar types of celestial bodies. William Herschel coined the term asteroid (a star-like body) to refer to such objects in 1802, writing that "it is so indistinguishable from the stars that the best telescope would have mistaken it for an asteroid ". As the first asteroid to be discovered, it is listed as Asteroid 1 Ceres in the modern asteroid numbering system.

In 2006, the debate over whether Pluto was a "planet" raised the question of whether Ceres should also be reclassified as a planet.

Before the International Astronomical Union formally defined a planet, a planet was defined as "a celestial body that: (a) has sufficient mass to overcome the forces of a rigid body by its own gravity so that it assumes a shape in hydrostatic equilibrium (approximately spherical ); (b) orbits a star and is not a planet or a satellite of a planet". According to this definition, Ceres would be the fifth planet in order from the inner solar system.

However, this definition was not accepted, and a new definition came into effect on 24 August 2006: "A planet fulfills (a) and (b) and must be cleared of objects in adjacent orbits".

By this definition, Ceres is not a planet (since its orbit in the asteroid belt is filled with millions of asteroids), and is classified as a "dwarf planet" (alongside Pluto and Eris) , but did not say whether it was an asteroid or not. In astronomy, there are also celestial bodies with dual identities such as comets in the asteroid belt, so it is not ruled out that a dwarf planet can have other names.

Ceres is by far the largest object in the asteroid belt, but as Kai

With the discovery of the Cypress belt and its celestial bodies, celestial bodies larger than Ceres were also found, including (28978) asteroids, (50,000 quaor stars), asteroids, and 2003 ub313 (Eris), etc., and the newly discovered The most distant celestial body (90377) Sedna star (sedna) may also be larger than Ceres, it may come from the inner layer of the Oort cloud. Pluto is also sometimes considered a Kuiper belt object.

Ceres may be a surviving protoplanet (infant planet), formed 4.57 billion years ago in the asteroid belt. Although most protoplanets of the inner solar system include all (Moon-Mars sized bodies) either merged with other protoplanets to become terrestrial planets, or were ejected outside the solar system by Jupiter, Ceres is believed to survive relatively intact (another A possible protoplanet is Vesta, which is smaller and suffered a major impact after solidification, losing ~1% of its mass), an alternative theory holds that Ceres formed in the Kuiper belt, later migrated to the asteroid belt.

The geological evolution of Ceres depends on the heat sources available during and after formation: friction from microsatellite accretion, various radioactive elements possibly including elements with short half-lives (such as al). These are thought to have been sufficient for Ceres to differentiate into a rocky core and an icy mantle shortly after formation. This process may have caused the surface to be reshaped by hydrovolcanism and geological formations, erasing ancient geological features.

Because of its small size, Ceres would have cooled relatively quickly and effectively prevented the processes that would have led to early geological reformation. Any ice on the surface will gradually sublimate, leaving behind various hydrated minerals such as clay and carbonates. Today, Ceres appears to be a geologically inactive object whose surface may have been affected by impacts.

The presence of a large amount of water ice in its composition makes it possible for Ceres to have a layer of liquid water inside, a hypothetical layer that might be called an ocean. If there is a layer of liquid water, it is believed that it will be borrowed between the core of the ancient body and the icy mantle, just like the ocean that theoretically exists in Europa. The presence of oceans is more likely to dissolve solutes (i.e. components such as salt, ammonia, sulfuric acid or other antifreeze) in its water.

Several mysterious bright spots on the surface of Ceres may be ejecting plumes of water vapor into space, suggesting that the dwarf planet is geologically active. NASA's Dawn probe took some images as it approached Ceres. Scientists pointed out at the Lunar and Planetary Science Symposium that the latest images show that Ceres' bright spots may be ice water materials, which will provide important clues to reveal the hidden substances beneath the planet's surface. .

Dr Andreas Naxons of the Max Planck Institute for Solar System Research in Germany said: "This plume changes over the course of the day on Ceres, becoming brighter during the day and brighter at dusk. The plume became dim and into the evening the plume disappeared completely."

The mysterious bright spots originally discovered by Hubble reappeared in recent images taken by the Dawn probe. Although scientists speculate that these bright spots contain highly reflective ice water, the Dawn probe has not yet been fully observed at close range. The latest data shows that These highlights are most likely ice water.

The brightest bright spot at present is called "Feature No. 5" by scientists. Photos taken from different times and angles during the day show that it is likely to be related to plume material. This area is located at the bottom of an 80-kilometer-diameter crater. "We think this bright spot is some kind of outgassing, and we need high-resolution image data to confirm that," Naxons said.

Not everyone is quick to accept the initial plume explanation. Bill McKinnon of the University of Washington in the United States said that you never see plumes with bright spots, frost and snow falling on the surface of Ceres, but we need to look further.

Ceres is large in size, round in shape and rich in water. It is a peculiar celestial body in the asteroid belt. Scientists speculate that Ceres has a subsurface ocean or frozen water layer. As a dwarf planet, it is more like a planet or ice Moons, not asteroids as astronomers previously understood.

Zhao Zhongyao looked at everyone, and explained to everyone the knowledge about this Ceres in detail, so that everyone can have a more detailed understanding of this Ceres.

It’s just that after Zhao Zhongyao explained this knowledge to everyone, he looked at everyone and said, ‘Actually, this Ceres is not only very magical in itself, but even the discovery of it itself is a magical thing. '

After hearing Zhao Zhongyao's words, Feifei asked curiously, 'Dad, what do you mean by this? What's so magical about discovering this Ceres. Isn't it just a certain astronomer who discovered it by accident! '

After hearing Feifei's words, Zhao Zhongyao said, "The magic of discovering this dwarf planet is that the credit for discovering this dwarf planet should be attributed to a mathematician." '

After hearing what his father said, Feifei said inexplicably, "How can it be attributed to a mathematician? The discovery of asteroids shouldn't be the work of astronomers, but how come it is the work of mathematicians." '

Zhao smiled again and said, 'It turned out that an astronomer discovered this asteroid. But after he discovered it, he fell ill without having time to observe it in detail. Then it can no longer be observed.

But when he recovered from his illness and wanted to observe again, he couldn't find this asteroid again. The astronomer was also very annoyed by this matter. It feels like I have a chance to discover an asteroid. But because of his illness, he missed such a good opportunity.

Later, after a mathematician heard about this incident, he had a whim. He wondered whether he could use mathematical methods to calculate where the escaped asteroid went.

So, this mathematician, after some hard work, developed a theory for calculating planetary orbits by himself. Using this theory, he only spent an hour,

Calculate the orbit of this asteroid.

The mathematician, after calculation, knew that this asteroid would appear in that sky someday in the future.

So he told some astronomers the news. Among them was a German astronomer named Olbers, who observed carefully with a telescope in the sky predicted by the mathematician.

Originally, the astronomer was just an amateur astronomer, and he didn't care much about the mathematician's predictions. Just because I love astronomy, I observed in the sky predicted by the mathematician.

Unexpectedly, with his observation, a miracle appeared. This asteroid that people are looking for has mysteriously appeared again. This time, people really discovered this asteroid. And named it Ceres.

This mathematician is actually the famous German mathematician Gauss. It is precisely because Gauss knew the orbit of this Ceres through calculations that an amateur astronomer discovered the trace of Ceres.

Therefore, mathematics is very important in astronomy. A good astronomer must be a mathematician. Because all astronomical discoveries rely on mathematical calculations.

In fact, this is not only true in astronomy, but also in many scientific fields.