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

After hearing his son's words, Zhao Zhongyao happily said, 'Let's go to Ceres.'

After saying that, Zhao Zhongyao drove the spacecraft and flew towards Ceres.

There is still a distance of hundreds of millions of kilometers from Pallas to Ceres. However, for the extremely fast flying saucer spacecraft, this distance is nothing. The flying saucer spacecraft can travel at the fastest speed in less than an hour.

Fly to Ceres.

During the flight to Ceres, Feifei wanted to ask her father to explain to them the knowledge about Ceres.

After all, Ceres is so famous. It can be said that among all the asteroids in the solar system, Ceres is definitely ranked first in fame.

Although everyone has heard of this asteroid, not many people know much about it. Everyone has only heard of this very large asteroid.

After listening to Feifei's words, Zhao Zhongyao said, "Okay, there are really endless topics to talk about about this Ceres. This asteroid is actually the most magical asteroid. First of all, he is now

It is no longer an asteroid. Ceres

, is now classified as a dwarf planet. Because it is too big among asteroids, but it is the smallest among dwarf planets. Therefore, Ceres is between asteroids and dwarf planets.

of a very special asteroid.'

After listening to Zhao Zhongyao's words, Feifei said, 'Dad, do you know this Ceres very well? Please tell us more about this Ceres.'

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

Next, Zhao Zhongyao talked about some knowledge about Ceres.

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

Planet, Ceres was once considered the largest known asteroid in the solar system.

Ceres is likely to be a differentiated planet with a rocky core and a mantle that contains a large amount of icy water. A large amount of water-carrying minerals have been detected on the surface of the planet. Preliminary estimates indicate that water accounts for 40% of the volume of Ceres. Ceres can also obtain energy from solar energy.

, because it is only 2.8 astronomical units from the sun. In comparison, Europa and Enceladus are farther away, 5.2 and 9 astronomical units respectively.

Ceres is located in the asteroid belt between the orbits of Mars and Jupiter. Previous studies have confirmed that there is a large amount of ice inside it. The European Space Agency reported in the journal Nature that they used the Herschel telescope to discover water vapor on Ceres for the first time.

, these water vapor come from darker areas on the surface of Ceres. The amount of water vapor is not

Large, about 6 kilograms per second, but this discovery is of great significance to confirm that there is water on Ceres. Researchers speculate that there may be two specific reasons for the emergence of water vapor: First, the ice on the surface of Ceres is rapidly heated by solar radiation

The second reason is that there is still energy inside Ceres. Scientists speculate that it may have an ocean of liquid water.

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

The classification of Ceres has changed many times, mostly due to disagreements among astronomers. John Bode believed that Ceres is the planet between Mars and Jupiter, 419 million kilometers (2.8 AU) from the sun.

"Missing planet". Ceres was given the symbol of a planet. Before more asteroids were discovered, Ceres (along with Pallas, Juno and Vesta) was listed as a planet in astronomy for nearly half a century.

in the book list.

However, as other celestial bodies were discovered in the same range, people gradually realized that Ceres was just one of many similar types of celestial bodies. William Herschel coined the term asteroid (star-like celestial body) in 1802

to call this kind of celestial body, and wrote that "it is so difficult to distinguish it from stars that even the best telescopes will think it is an asteroid." As the first asteroid discovered, according to the modern asteroid numbering system

Listed as asteroid 1 Ceres.

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 rigid forces with its own gravity, and therefore can assume the shape of a hydrostatic equilibrium (close to a sphere).

); (b) orbiting a star and not being a planet or a satellite of a planet. According to this definition, Ceres would be the fifth planet in sequence from the inner side of the solar system.

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

According to this definition, Ceres is not a planet (because its orbit in the asteroid belt is filled with thousands of asteroids), and is classified as a "dwarf planet" (along with Pluto and Eris)

, but it did not explain whether it is still an asteroid. 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 celestial body in the asteroid belt, but with the discovery of the Kuiper Belt and its celestial bodies, celestial bodies larger than Ceres have also been found, including (28978) asteroids, (50000 Quar stars), small

Planets and 2003

UB313 (Eris), etc., and the newly discovered most distant object (90377) Sedna may also be larger than Ceres, and it may come from the inner layer of the Oort cloud. Pluto is sometimes considered to be in the Kuiper Belt

Celestial bodies.

Ceres may be a surviving protoplanet (an embryonic planet) that formed in the asteroid belt 4.57 billion years ago. Although most protoplanets in the inner solar system, including all (Moon-Mars-sized bodies), are not the same as other protoplanets,

Planets merge to form terrestrial planets, which are ejected out of the solar system by Jupiter

, Ceres is believed to be relatively intact (the other possible protoplanet is Vesta, which is smaller and suffered a major impact after solidification, losing ~1% of its own mass), a replacement

The theory is that Ceres was formed in the Kuiper belt and later migrated to the asteroid belt.

The geological evolution of Ceres depends on the heat sources available during and after its formation: friction from planetesimal accretion, a variety of different radioactive elements, possibly including elements with short half-lives (such as Al). These are thought to be sufficient to allow Ceres to grow rapidly after its formation. Soon it differentiated into a core of rock and a mantle of ice. This process may have caused the surface to be reshaped by hydrovolcanoes and geological structures, erasing ancient geological features.

Because of its smaller size, Ceres cools faster and effectively prevents the processes that would have reshaped its early geological structure. Any ice on the surface will gradually sublime, leaving behind a variety of hydrated minerals, such as clays and carbonates. Today, Ceres appears to be a geologically inactive object, and its surface may have been affected by impacts.

A large amount of water ice exists in its composition, so there may be a layer of liquid water inside Ceres. This hypothetical layer may be called an ocean. If there is a layer of liquid water, I believe it will be borrowed from the core of the ancient body and the icy mantle. in between, like the oceans that theoretically exist on Europa. The presence of the ocean is more likely to dissolve solutes (i.e. salts, ammonia, sulfuric acid or other antifreeze ingredients) in its water.

Several mysterious bright spots on the surface of Ceres may eject water vapor plumes into space, suggesting that the dwarf planet has very active geological activities. NASA's Dawn probe took some images as it approached Ceres, scientists said at the Lunar and Planetary Science Symposium It was pointed out that the latest images taken show that the bright spot on Ceres may be ice water material, which will provide important clues to reveal the materials hidden under the surface of the planet.

Dr. Andreas Nasons of the Max Planck Institute for Solar System Research in Germany said: "This plume changes continuously throughout the day on Ceres. During the day, the plume becomes brighter and during the twilight hours, the plume becomes brighter. The plume becomes dim, and into the evening the plume disappears completely."

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

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

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

Ceres is larger in size, round in shape, and rich in water. It is a strange 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 the knowledge about this Ceres star to everyone in detail, so that everyone could have a more detailed understanding of this Ceres star.

But after Zhao Zhongyao explained this knowledge to everyone, he looked at everyone and said, 'Actually, this Ceres is not only very miraculous in itself, but even its discovery itself is a miraculous thing.'

After hearing what Zhao Zhongyao said, Feifei asked curiously, 'Dad, what do you mean by this? What's so magical about the discovery of Ceres? Wasn't it discovered by an astronomer by chance?'

After listening to 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 listening to her father's words, Feifei said in confusion, 'How can it be attributed to a mathematician? The discovery of asteroids should not be a matter of astronomers, but how come it has become a matter of mathematicians.'

Zhao smiled again and said, "Originally, an astronomer discovered this asteroid. But after he discovered it, he didn't have time to observe it in detail. He fell ill. Then he could no longer observe it."

But after he recovered from his illness, when he wanted to observe again, he could not find the asteroid again. The astronomer was very upset because of this. He felt that he had a chance to discover an asteroid.

Planet. But due to my illness, I missed such a good opportunity.

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

So, after a lot of hard work, this mathematician developed a theory for calculating planetary orbits. He used this theory to calculate the orbit of this asteroid in just one hour.

After calculation, this mathematician knew where this asteroid would appear in the sky one day in the future.

So, he told some astronomers about the news. One of them, a German astronomer named Obers, used an astronomical telescope to observe carefully 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 he loved astronomy, he observed the sky predicted by the mathematician.

Who would have known that after his observation, a miracle occurred. This asteroid that people were looking for appeared mysteriously again. This time, people actually discovered this asteroid and named it.

For Ceres.

This mathematician was actually the famous German mathematician Gauss. It was precisely because Gauss knew the orbit of Ceres through calculations that an astronomy enthusiast discovered the traces of Ceres.

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