Why is the Kepler-90 star system the second solar system? First of all, the only star in the Kepler-90 system is similar to the Sun, and this star is also surrounded by 8 planets like the Sun, which means that the system and the solar system are as prosperous.
What Kepler 90 looks like
The so-called Kepler 90, is the Kepler space telescope found that there is a planet of the 90th star, this star is located in the direction of Draco, the mass is about 1.13 times the Sun, the same as the Sun is a yellow dwarf, the surface temperature is slightly higher than the Sun, about 5930K, so the brightness is slightly higher, the absolute magnitude is about 4.54, a little brighter than the Sun's 4.83, but because of the distance we have 2545 light years, the apparent magnitude is only 14 magnitude, the human eye can not see.
It was said many times that the brightness of celestial bodies is measured by magnitude, the magnitude is the smaller the value, the brighter, and the negative number, the more negative the brighter, the difference in brightness between each magnitude is 2.512 times. I won't go into detail today.
Now do you know why this Kepler 90 is the Sun Brothers? It's about the size of the sun, it's almost bright. But it is clearly the sun's brother, because it was born 2.6 billion years later than the sun, only 2 billion years old, and the sun brother is already 4.6 billion years old.
What's even more bizarre is that the families of these two brothers have 8 senior disciples, or children. The Sun has 8 planets, and Kepler 90 is also an 8 planet. These planets are b, c, i, d, e, f, g, h according to the closest planet, and the nearest planet is called Kepler 90b, and the farthest planet is called Kepler 90h.
The case of the eight planets
According to the principle of planetary naming, the original serial numbers are b, c, d, e, f, g, h, i, and this i should be ranked last, that is, farthest. But because this "i" star was the last to be discovered, and the first 7 planets had long been discovered and named, if you had to rearrange the seats, it would be messed up. Because over the years people have been familiar with and used those planet numbers in many sources.
Thus, the i-star becomes a third party, interjected between c and d.
The Kepler Space Telescope is a telescope launched by NASA (SHORT for NASA) in 2009 to find exoplanets, and the way to find planets is to use the transit method, that is, when the planets move between humans and stars, according to the changes in the luminosity of the stars to "guess". Therefore, this method can only find planets and roughly know the volume of these planets, and it is difficult to determine the mass of the planets, let alone see what the planets look like.
The data obtained by the Lingxing method is that the 8 planets of Kepler 90 are all larger than the Earth, the largest volume is Kepler 90h, the radius is 11.32 times that of the Earth, and Jupiter is about the same, and it is also so large that it is lost; the smallest volume is Kepler 90c, with a radius of about 1.2 times that of the Earth.
There are other methods of observing exoplanets, such as gravitational perturbation, which estimates the mass of the planet by observing the effect of gravitational force on the star. Using this method, scientists have a preliminary understanding of the mass of the three planets in the Kepler-90 system, such as i, g and h, which are about 2.5 times that of Earth, 0.8 times of Jupiter, and 1.2 times that of Jupiter.
From the mass state of these planets, it can be seen that the mass of these planets is similar to that of the solar system, and the masses of planets near the stars are relatively small, belonging to Earth, Venus, Mars, Mercury and other terrestrial planets; while the planets far away from the stars are relatively large, belonging to gaseous planets such as Jupiter, Saturn, Uranus, and Neptune.
The high similarity between the Kepler-90 planetary system and the solar system is due to the universality of the process of star and planetary system formation. This has been said many times in the past, but today it is not ripped off.
The planet most like Earth, Kepler-90i, is what it looks like
In fact, since 2009, NASA has begun to pay attention to kepler 90 stars, Kepler telescope with a photometer to observe whether this star has a luminosity decline of the transit star event, from the discovery of the first planet in 2013, successively found 7 planets around Kepler 90, until 2017, finally discovered the Kepler 90i.
The discovery was made by "picking up leaks", which was found by combing through the past observations of the Kepler telescope. According to NASA, the discovery also benefited from the use of new computer calculus tools, which is to put it bluntly, the use of IA (artificial intelligence). It was Google engineer Christopher Shalu and Austin University astronomer Andrew Vanderbilt who followed the weak signal that had previously been ignored, found through the IA.
The study found that this planet ranks third from Kepler 90 stars, exactly the same order as our earth in the solar system, and is a rocky planet like Earth, with a radius of 1.32 times that of Earth and a mass of about 2.5 times that of Earth. So, will there be life or civilization on it?
Studies have shown that this is unlikely, because the planet is so close to the host star that it is only about 0.1234 AU (astronomical units, about 150 million km) and has an orbital period of only 14.45 Earth days, that is, about 14 days or more to orbit the star, while the Earth orbits the sun for one year.
In the Solar System, Mercury is closest to the Sun, about 0.38 AU, and Kepler 90i is much closer to the Sun than Mercury, so it is scorched by the high temperature of the star, and the surface temperature is very high, at least reaching the surface temperature of Mercury or Venus, that is, about 500 ° C.
So close to the star that even if there is an atmosphere, it will be evaporated and blown away by the stellar wind, so it is unlikely that Kepler-90i will have an atmosphere. Planetary rotation may also have been locked by the gravitational tides of the star, that is, only one side is always facing the star, and the other side is always carrying the star. In this way, the side facing the star will always be scorched by the heat wave of the star, and the side carrying the star will be cold as an ice cave, and the temperature will be below minus 100 ° C.
In such a state, it is difficult to have liquid water, so it is unlikely that Earth-like life will be conceived and survive there. However, some people think that on such planets, near the morning and evening lines (that is, at the junction of the sun and no sun) there is likely to be a suitable temperature, perhaps there is liquid water and suitable conditions for life.
But without the atmosphere, the rotation cycle is so fast, the probability of life and civilization is too small, will miracles happen on this planet? H star, which is just 1 AU away from the star, is also a wood-like giant planet, and the probability of life in this gaseous planet is even smaller.
The Kepler-90 planetary system is just a mini solar system
Saying that the Kepler-90 system is a mini-solar system does not refer to its main star, which is larger than the Sun. But all the planets are too close to the star, and the farthest h star is only about 1 AU from the host star, that is, the Earth is so far away from the sun, and in the middle of the h star and the host star, there are 7 planetary orbits.
In the solar system, the closest thing to the Sun is Mercury, about 0.38 AU; the furthest is Neptune, about 30 AU. Thus the circle of the solar system planetary system is exactly 30 times larger than the circle of the Kepler-90 planetary system. And beyond Neptune, there is the Kuiper Belt, which contains many frozen dwarf planets, and Pluto is one of them, with an average distance of 40 AU from the Sun.
In the 10 years since the Kepler space telescope was in service, it has found 2662 exoplanets, accounting for more than 60% of the exoplanets found by humans now, and has found a variety of Earth-like planets, dozens of which are in the habitable zone, and there is hope for life. But because human observations are still weak overall, no evidence of extraterrestrial life or civilization has been found.
Now that the Kepler Space Telescope has been retired, many space telescopes have inherited their unfinished business. Recently, NASA launched the most expensive and advanced Weber space telescope ever launched, a telescope that has been developed and launched at a cost of $10 billion, and its comprehensive function is many times more powerful than the previous hubble space telescope, theoretically seeing the earliest galaxy formation after the Big Bang, that is, the baby universe.
As scientific observation capabilities improve, will more secrets be discovered in the Kepler 90 galaxy? Or maybe extraterrestrial life and civilization will soon be discovered? Of course, the premise is that extraneous life and civilization really exist, and the density is not too thin. What do you think? Welcome to the discussion, thanks for reading.
Space-time communication original copyright, infringement and plagiarism is unethical behavior, please understand the cooperation.