How many planets are there in the solar system? There are currently 8 of them, but many astronomers believe that a ninth planet is likely to be hidden in the depths of the universe.
Astronomers have been searching for this hidden planet for years, but some believe it doesn't exist, otherwise it should have been discovered a long time ago with human observation. Astronomers who believe in its existence have come up with various theories, and some even believe that this "planet" is actually a very small but massive planetMiniature black holes, so it's not easy to find.
In the beginning, astronomers searched for new planets, just because they had completed the previous discovery, and continued the same exploration, as if someone had lived to be 120 years old, and everyone would wonder if anyone would live to be 121 years old.
At that time, Pluto had just been discovered, and there were still nine planets in the solar system, so people called this unknown planet x. The letter x is not only used as an important symbol for unknown numbers in equations, but also happens to be 10 in Roman numerals, which means the tenth planet.
Later, Pluto was kicked out of the ranks of the stars, but astronomers are still searching for unknown planets in the solar system and still call it X.
Although Pluto was eliminated, it offered a possibility to the unknown ninth planet. It is precisely because of the existence of Pluto that astronomers think and even believe that the ninth planet really exists, instead of just guessing wildly.
Pluto's characteristic is that the orbital eccentricity is too large. We all know that the orbit of a cosmic body is elliptical, but compared to the orbit of other planets that are close to a perfect circle, Pluto's orbit is too "elliptical" and ridiculously flat. At its farthest point, it is about 7.4 billion kilometers from the Sun, but its perihelion is less than 4.5 billion kilometers, closer than Neptune.
Not only that, but in Pluto's positionKuiper Belt, other celestial bodies also have such outrageous eccentricities. For example, the perihelion of the planet is about 56500 million kilometers, but the aphelion reached 14.6 billion kilometers; Ornith, perihelion 57600 million km, aphelion 79400 million kilometers ......
Obviously, their orbits do not correspond to the laws of normal solar system celestial bodies, so astronomers speculateThere must be a huge hidden planet that interferes with these Kuiper Belt objects through its gravity to cause this strange way of behaving in this way
Professor Mike Brown of the California Institute of Technology has always been convinced of the existence of the ninth planet, and has published many times to explain the progress of his work.
Recently, he showed the public the progress of his and his team's current work, which has completed almost 80% of the surveys in the area where they believe Planet 9 is possible. That is, in their beliefs, the ninth planet exists in the last 20%.
Their observations were utilizedPan-Star Projectdata. Pan-starrs, full namePanoramic survey telescope and rapid response system(Panoramic Survey Telescope and Rapid Response System) is the use of a telescope at the Haleakala Observatory on the island of Maui, Hawaii, to repeatedly observe the starry sky in the universe and then compare it with the same area.
For objects outside the solar system, the time interval between shots is not enough to produce a noticeable change in position due to the distance being too far. However, if it is a celestial body in the solar system, the position change is more obvious, and it is easy to obtain. In fact, that's how Pluto was discovered in the first place.
The Pan Star Project is able to conduct almost four inspections of the entire sky every month, which is unprecedented. Moreover, the observation ability of the Panstar Program Telescope is also very strong, and the faintest can observe 24th magnitude stars. What is this concept? Let's put it this wayEven the faintest magnitude 6th magnitude star visible to the naked eye is more than 15 million times brighter than this!
After the release of the second phase of the Sky Survey, Brown's team analysed the data in an attempt to look for signs of a possible ninth planet. Regrettably,They analyzed about 78 percent of the area calculated by previous studies and found that there was no sign of the ninth planet.
For the average person, this means that the likelihood of the existence of the ninth planet has been greatly reduced. But for Brown and others, it's good news, saying in an interview: "That means we've narrowed down our search considerably." ”
His team not only searched for this mysterious celestial object with their eyes, but also tried to speculate on its possible form through theory.
As we said earlier, the strange orbit of the Kuiper Belt may have been created by gravitational interference on the ninth planet. That being the case, through their orbital patterns, astrophysicists can deduce the magnitude of gravity and guess the properties of this hidden planet.
Different astronomers have calculated different results, according to the latest estimates from Brown's teamThe mass of the ninth planet is about 6 of Earth's6 times,Once discovered, it will be the fifth largest planet in the solar system. You know, there is now a mass difference of more than 15 times between Uranus, the fourth largest planet in the solar system, and Earth, the fifth largest planet, and there is a huge fault line between them. Planets with a mass of only several times that of the Earth are common outside the solar system, so such planets should also be hidden within the solar system.
But this large planet is extremely difficult to observe because it is extremely far awayThe semi-major axis of the orbit is about 500 astronomical units, or almost 75 billion kilometers!
Despite the difficulties of finding Planet 9, Brown is confident and ready for the next step, which is to use the LSST project for a new search. The full name of LSST isSurvey of Space-Time Heritage(Legacy Survey of Space and Time), planned for 10 years, in ChileVera Rubin Observatory
The observatory is still under construction and is currently unusable. However, it is speculated that within a year or two, or even as early as the second half of this year, this ambitious project will be completed, and the project is even ranked with Chang'e-6 as one of the six most anticipated scientific events of the year in the journal Nature**, which shows its strong observation capabilities.
Brown believes that once the observatory is operational, the ninth planet will have nowhere to hide. As long as this planet really exists, humans will quickly expose it to Lushan's true colors.