Post by glaucus on Apr 15, 2022 13:27:13 GMT
Ceres, Pallas, and Vesta are highly atypical asteroids.
They're actually protoplanets aka planetary embryos, and that's one of the reasons why they're more important than all the other asteroids including Juno which is not a protoplanet like the other three.
The four asteroids were categorized as planets before. They were downgraded after astronomers realized they're just part of a population of minor planets located between Mars and Jupiter just like astronomers realized that Pluto is just part of a population of minor objects located in the outer regions of the solar system.
The fact is that Pluto was found by Clyde Tombaugh because it was orbiting on the ecliptic at the time. Pluto travels up to 17 degrees away from the ecliptic. Pluto wasn't the only transneptunian object that was orbiting on the ecliptic. Transneptunian dwarf planet Haumea was orbiting on the ecliptic, but Tombaugh failed to spot it while looking for more transneptunian objects. Pluto was originally thought to be large as Earth. Then it was thought to be large as Earth's Moon. The discovery of Charon in 1978 allowed astronomers to calculate Pluto's mass which led them to realize that Pluto was much smaller than both Earth's Moon and Mercury. They also realized that Pluto was Percival Lowell's hypothesized Planet X for it was too small to affect the orbit of Uranus. In the 1990s, errors in the calculation of Neptune's mass was found which led to no need to search for Percival Lowell's hypothesized Planet X. Clyde Tombaugh found Pluto by accident.
From 1930 to 1978, Pluto was thought to be much bigger than it actually was. I am very sure that Pluto's previously thought size factored in Modern Western Astrologers being very interested in Pluto in Astrology. Of course, size mattered to them. They totally ignored Ceres, Pallas, Juno, and Vesta and didn't include them in their astrological systems even though they were categorized as planets for around 40 years and then got downgraded. The size ratio between Earth and Pluto is far greater than the size ratio between Pluto and the other transneptunian dwarf planet/candidates with Eris almost the same size as Pluto. The whole "they're just small rocks" argument isn't going to cut it. There are strong double standards and hypocrisy among Astrologers.
Universe Today
Protoplanets are small celestial objects that are the size of a moon or a bit bigger. They are small planets, like an even smaller version of a dwarf planet. Astronomers believe that these objects form during the creation of a solar system.
The most popular theory of how a solar system is formed says that a giant cloud of molecular dust collapsed, forming one or more stars. Then a cloud of gas forms around the new star. As a result of gravity and other forces, the dust and other particles in this cloud collide and stick together forming larger masses. While some of these objects break apart on impact, a number of them continue to grow. Once they reach a certain size – around a kilometer – these objects are large enough to attract particles and other small objects with their gravity. They continue to get larger until they form protoplanets. Some protoplanets continue colliding and growing until they form planets while others stay that size.
As the protoplanets grew to become planets, parts of them melted due to radioactivity, gravitational influences, and collisions. Where the objects had melted, the composition of the planets changed. Heavier elements sank, forming the cores of the planets, and lighter objects rose to the surface. This process is called planetary differentiation and explains why planets have heavy cores. Astronomers have discovered that even some asteroids have differentiated, so their cores are heavier than their surfaces.
Protoplanets used to be highly radioactive due to how they were formed. However, over thousands of years, the radioactivity of these objects has greatly decreased because of radioactive decay. Astronomers are still discovering new protoplanets, and most likely, they will discover many more. With better technology, astronomers are now able to find protoplanets in other star systems. Last year, scientists discovered a protoplanet HL Tau b that will probably turn into an actual planet one day. Astronomers say that will not happen for about a million years though because the protoplanet’s star is also very young. In its final form, HL Tau b will look like Jupiter – a gas giant around the same size as that massive planet. It is hard to believe that thousands of years ago our planets were objects about the size of a moon, which were slowly evolving and growing. Astronomers continue to study protoplanets, the same way they study planetesimals, to find out more about how the Solar System was formed.
www.universetoday.com/37053/protoplanets/
Of course, Ceres is the one stands out of all asteroids with it being the only one that is categorized as a dwarf planet. Ever since I got into Asteroid Astrology over 20 years ago, I always thought Ceres was highly underrated in Astrology. Chiron gets a lot more respect than Ceres in Astrology even though Chiron is 1/3 of the size of Ceres. Solar Fire has interpretations for Chiron aspects and has interpretations for Ceres aspets. The Adze Astroinsight Report is the same thing. Magi Society has been viewing Chiron as a special planet with great astrological significance and even claim that it has to do with marriage and soulmates, and they stressed that in their 3rd book. There was no mention of Ceres at all. I was a glad that Ceres got astronomically upgraded and Pluto got astronomically downgraded leading to Ceres finally being Pluto's astronomical equal as the result of the discovery of Eris.
Ceres may have formed in the outer regions of the Solar System
Strange dwarf planet Ceres may have formed at the icy edges of the solar system
By Paul Sutter published 28 days ago
The dwarf planet Ceres is located in the asteroid belt but looks nothing like its neighbors. In a new paper, scientists propose an explanation for the conundrum.
Ceres, the most dominant member of the asteroid belt, doesn't look like the other asteroids. Most notably, it has a lot of ammonia on its surface, which other asteroids tend to lack. The only place to get a lot of ammonia is in the outer regions of the solar system in the early days of its formation.
In a new paper, researchers propose a possible explanation for why Ceres is so different from its neighbors: Perhaps the dwarf planet began in an orbit beyond Saturn and, during a massive reshuffling of the outer planets, got planted into the asteroid belt, where it has remained to this day.
A Ceres matter
With a radius of 296 miles (476 kilometers), Ceres is by far the largest object in the main asteroid belt, the loose collection of rocks between the orbits of Mars and Jupiter. The vast majority of asteroids are far smaller than Ceres; in fact, by itself, Ceres accounts for over one-third of the entire mass of the belt.
And Ceres is weird.
NASA's Dawn spacecraft spent several years in orbit around Ceres, mapping and studying its surface. That mission found that the surface is a mixture of water ice minerals bound with water, like clay and carbonates. Beneath that is a mantle rich in water ice surrounding a core of mainly solid rock.
Ceres has a relatively low density (2.2 grams per cubic centimeter) and a rather low albedo, meaning it's not very reflective. This makes Ceres very similar to the most common kind of asteroid, the C-type — or carbonaceous chondrite — asteroids. Indeed, Ceres' location within the main asteroid belt puts it close to other C-type asteroids.
But most C-type asteroids don't have that much water and don't have so many clays. And Ceres also has a lot of ammonia on its surface, which almost all other asteroids lack. Ammonia isn't common in the inner solar system, where the intense heat of the sun evaporated it in the early days of the system's formation. Instead, ammonia survived only beyond the "ice line," the distance from the sun where volatile elements like ammonia could survive.
Indeed, Ceres doesn't really look, smell or act like an asteroid. Instead, the dwarf planet has more in common with the most distant objects in the solar system — the members of the Kuiper Belt, like Pluto, Charon and Eris.
Scientists have proposed explanations for each strange trait. Maybe Ceres formed inside the asteroid belt, in a really weird way that allowed it to maintain a lot of water. Maybe it formed without disrupting the rest of the main belt. Maybe over the course of billions of years, a lot of ammonia floated in from the outer solar system and found itself on the surface of the dwarf planet (and not the other asteroids).
Or maybe, the authors of the new paper propose, Ceres was born beyond the orbit of the giant planets and got sent into the asteroid belt long ago.
A song of ice and also ice
The early solar system was a chaotic place. Thousands of small celestial bodies called planetesimals jostled and fought for dominance, aggregating into planets only to be smashed apart again. Among these multitudes was a vast population sitting outside the giant planets, according to the new paper, posted to the preprint database arXiv.
The most common model of the early solar system, called the Nice model (named for the city in France where a conference on solar system formation took place), states that the giant planets of the solar system formed closer to the sun, and closer to one another, than their present-day locations. Some versions of the Nice model also
When those planets began to migrate to their modern positions, it shook things up a lot. The large population of Kuiper Belt objects were disrupted, their orbits perturbed by the motions of the giant worlds. Some of them were ejected completely from the solar system. Some crashed into each other and were obliterated. Some were captured, as in the case of Neptune's moon Triton.
And perhaps others made their way into the inner solar system.
Homeward bound
But even if Ceres-type worlds made it into the asteroid belt, it wasn't smooth sailing from there. Astronomers already knew that the disturbances of the outer system affected even the asteroids, causing the belt to lose up to 80% of its objects. So it was a serious challenge for something like Ceres to end up in the asteroid belt and persist to the present day.
It required a lot more objects like it. The researchers estimated that if at least 3,500 Ceres-size objects existed beyond the orbit of Saturn in the early solar system, at least one of them would make it into the asteroid belt and stay there. Those estimates are based on computer simulations that tracked the evolution of planetary orbits during the disruptive phase of the outer-planet migration. Thousands of Ceres-size objects sounds like a lot, but it's actually well within the range that other models suggest for populations of the outer system.
The conclusion: The most likely explanation for Ceres is that it was born in the icy edges of the solar system and was the luckiest member of a group of objects that were displaced when the giant planets shifted their positions.
The asteroid belt and the Kuiper Belt remain some of the best laboratories for understanding the formation of the solar system. Any model of planetary formation and evolution must include their effects on the smallest objects orbiting the sun. And so Ceres just may be the major clue we need to understand what happened in the solar system over 4 billion years ago.
www.space.com/ceres-dwarf-planet-mysteries-formation-theory