The World Of Asteroids
The ancient Greeks looked at the heavens and called the seven points in the sky - Mercury, Venus, Mars, Jupiter, Saturn, The Moon and The Sun “Planets” (Wanderers in Greek). So basically, if anything moved across the sky and was bright, they called it a planet. Also, it was believed that the Earth was the center of the Universe.
Now this is a terrible start for the planets because, they couldn’t know how different the Moon was from planets, because the technology they had to observe the Universe was really limited.
It would take several thousand years until in 1608, “Hans Lippershey”, a German-Dutch spectacle maker, made an invention which was later improvised by an Italian astronomer “Galileo Galilei”, to what we call as the telescope. All these telescopes were made by lenses and thus were called as Refractors.
The English astronomer “Sir Issac Newton”, used mirrors instead of lenses and made his own design, which we call as the Reflectors-these famous words -“If I have seen further, it is by standing on shoulders of giant make us realise how the universe was now an open field for research.
But, something strange happened in 1772, when German astronomers Johann Bode and Johann Titius, published a numerical procession known as the Titius-Bode Law. This law seemed in particular to follow the astonishing relation which the known six planets were observed in their distances from the Sun. The Titius-Bode law got a boost with Sir William Herschel’s discovery of ”Uranus” near the predicted distance for a planet beyond Saturn in 1781.
Bode's formula predicted another planet would be found with an orbital radius near 2.8 AU from the Sun. Except for this unexplained gap between Mars and Jupiter, Bode's formula seemed to predict the orbits of all the known planets.
In 1800, a group headed by Franz Xaver von Zach, editor of the German astronomical journal Monatliche Correspondenz, sent requests to 24 experienced astronomers (whom he dubbed the "Celestial Police” ), asking that they combine their efforts and begin a methodical search for the expected planet between the orbits of Mars and Jupiter.
But, before receiving his invitation to join the group, Giuseppe Piazzi, a Catholic priest at the Academy of Palermo, Sicily, discovered a new object on 1 January, 1801. He was searching for "the 87th star of the Catalogue of the Zodiacal stars of Mr. La Caille”, but found that "it was preceded by another". Instead of a star, Piazzi had found a moving star-like object, which he first thought was a comet.
At 2.8 AU from the Sun, this recently discovered object appeared to fit the Titius-Bode law almost perfectly. Giuseppe Piazzi named the newly discovered object Ceres Ferdinandea, ( most commonly - Ceres ) "in honour of the Patron Goddess of Sicily and of King Ferdinand of Bourbon.”
Later, Ceres was added to the list of planets. A tiny, little planet located in between the orbit of planets, Mars and Jupiter. The whole world was pretty amazed. Wow, a new planet, that’s exciting and that’s how Ceres got added to the list of planets everyone learned - Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn and Uranus.
Later, “The Celestial Police” group found three more planets, Pallas, Juno and Vesta all located in between the orbits of planets, Mars and Jupiter, not too far from Ceres actually.
Now, children in school learned the names of the planets as Mercury, Venus, Earth, Mars, Ceres, Pallas, Juno, Vesta, Jupiter, Saturn and Uranus.
Now, by this point you can see, if you are learning the names of the planets, that’s getting to be a pretty long list and it kept getting harder and harder to learn, because guess what, just a few years later, thousands of these little planets were found between Mars and Jupiter.
Astronomers realised that, with all these tiny little planets that kept getting discovered, they were dealing with something new, something unusual.
Do you know what these tiny little planets found between the orbit of planets Mars and Jupiter are ?
Well, they got their own special name. Maybe you’ve heard of them before - “ASTEROIDS.”
The “Celestial Police” group confirmed or discovered the four largest minor planet ( an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet ), which would lead to the identification of the “Asteroid Belt.” They also initiated the compilation of better star catalogues and the investigation of variable stars. They pioneered international collaboration and communication in Astronomy.
We know today that asteroid is a minor planet – an object that is neither a true planet nor an identified comet - that orbits within the Inner Solar System. They are rocky, metallic, or icy bodies with no atmosphere. The size and shape of asteroids vary significantly, ranging from small rubble piles under a kilometre across and larger than meteoroids, to Ceres, a dwarf planet almost 1000 km in diameter.
Of the roughly one million known asteroids, the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun. Rather than learning all of their names, we simply call the whole area in between the orbits of planets Mars and Jupiter, “THE ASTEROID BELT.”
Since, when you make a map of it, it kind of looks like the shape of a belt going around the Sun.