| There will be either 8 or 10 planets in the solar system Pluto is in danger of being demoted in rank - astronomers are ready to deny it the status of a “big planet” and relegate it to the category of ordinary asteroids. And all because scientists found a “little brother” for him. This sensational discovery was recently confirmed by decoding images taken by the Hubble orbital telescope.
In June 2002, Californian astronomers Chad Trujillo and Mike Brown discovered a new solar satellite, number 2002 LM60, beyond the orbit of Pluto. However, observations from Earth could not give an exact answer to the question about the size and nature of this celestial body. Recently, this satellite, tentatively named Quaoar (the name of one of the deities of the California Indians), was photographed from space by the Hubble telescope. It turned out that it is a piece of ice and rock and has about 1250 kilometers in diameter (two and a half times smaller than our Moon). Quaoar makes a complete revolution around the Sun in 288 years, in an almost circular orbit at a distance of 6.3 billion kilometers. The only problem remains: should Quaoar be recognized now - the tenth planet of the Solar System or another of the small asteroid planets?
The fact is that where the new satellite was discovered, there is the so-called Kuiper belt, discovered in 1992. Astronomers believe that it consists of many small fragments of ice and rocks orbiting the Sun. Their size ranges from several meters to several tens and even hundreds of kilometers. These fragments may have been the “building material” from which the planets of the solar system were formed in prehistoric times. Before the discovery of Quaoara, the small planet Varuna with a diameter of about 900 kilometers was considered the largest of the Kuiper Belt asteroids. But the next largest objects in this area were the ninth planet Pluto (2274 kilometers) and its satellite Charon discovered in 1978 (1172 kilometers).
But the unexpected discovery of Quaoar confronted astronomers with a choice: where in the Kuiper belt should we draw the line between large planets and asteroids? On the one hand, Pluto is only about a thousand kilometers larger than Quaoar and is considered a large planet. But Varuna is only a quarter smaller than it, but is an asteroid. In other words, any decision will be very conditional.
Perhaps this would be the most logical option. For quite some time now, astronomers have expressed the opinion that considering Pluto the ninth planet of the solar system is at least strange. The fact is that the previous large planets (Neptune, Saturn and Jupiter) are gas giants. Pluto is completely different from them: it is much smaller and is not a cloud of gases, but a frozen rock. In addition, it is the only large planet with an “irregular orbit” - at times Pluto is even closer to the Sun than Neptune. Similar pieces of icy stones - only smaller in size - make up the Kuiper Belt. The only way Pluto differs from these asteroids is its relatively large size. But after Californian astronomers found the “overgrown asteroid” Quaoar, this difference does not seem so significant.
Another reason that Pluto was included in the large planets was that it was discovered back in 1930. Telescopes of that time were quite weak, so it was almost impossible to see small objects beyond the orbit of Neptune. Telescopes began to be launched into space much later. Even the fact that Pluto has a large satellite became clear only in 1978. (By the way, it is curious that if not for the imperfection of technology, Quaoar would have been discovered 20 years earlier. Its first image was obtained back in 1982, but then scientists were unable to determine what exactly this bright speck is.) Now, With several large asteroids already discovered in the Kuiper Belt, astronomers believe that in 1930 scientists may have been a little hasty in recognizing Pluto as the ninth major planet. Vladimir DZAGUTO |
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