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This planet was discovered by kepler mission. During the four-year mission, Kepler telescope has been staring at a small sky area near Cygnus for continuous observation. The newly discovered planet is located in Kepler's observation field of vision and belongs to Cygnus.

How far is it?

Kepler 452b revolves around a sun-like star, about 1400 light-years away from the earth. It will take about 30 million years to reach the planet at the speed that the New Horizon probe flies over Pluto, that is, 14 km/s, but considering that the speed of the New Horizon probe will further slow down when it is far away from the sun, the actual time will only be longer. Of course, New Horizons didn't fly in the direction of Kepler 452b, so it will never fly there.

Can you see it?

Don't say this planet, even the stars around it, we can't see it with the naked eye on earth, even in the best star-watching environment. The brightness of most stars monitored by Kepler telescope is between 14- 16, which is similar to Pluto seen on earth. In fact, even with the most powerful telescope on earth, it is impossible for astronomers to see the planet directly, let alone see it clearly.

How did you find out?

Kepler 452b revolves around a star. Every time it makes a revolution, it just passes in front of the star once, blocking part of the starlight sent by the star to the earth. So on earth, it seems that every once in a while, the brightness of this star will suddenly dim in a short time. This phenomenon is called Ling Xing. If the star darkens periodically for a short time, it may mean that there is such a planet around the star. This is also the main method for Kepler telescope to find extrasolar planets.

How big is it?

The bigger the planet, the more starlight it blocks during transit, and vice versa. Therefore, by accurately measuring the dimming range of star brightness during the transit, the relative sizes of planets and stars can be accurately determined. The size of a star can be inferred by an accurate model of the star. Therefore, even if astronomers can't see the planet at all, they can still measure that Kepler 452b is 60% larger in diameter than the Earth through Ling Xing observation. This is the only parameter that astronomers can determine about the planet itself. As for other important parameters, such as its mass, what material it is made of and the temperature, astronomers still know nothing.

Is it a rocky planet?

In our solar system, planets are clearly divided into two categories: one is mainly composed of rocks like our earth; The other is much larger than the earth and is mainly composed of gas. But astronomers can't accurately judge Kepler 452b. Its diameter is bigger than that of the earth, and it's not too big. According to the reasonable "guess" of the discoverer, Kepler 452b is probably a rocky planet. However, Leslie. Astronomer Rogers of California Institute of Technology published a study in the Journal of Astrophysics this year, counting a large number of extrasolar planets with known sizes and masses, and proved that most Kepler 452b-sized planets are not rocky planets [1]. Therefore, it is not certain that it is a rocky planet. [7]

Is there life?

To be exact, no one knows whether there is life there, not even astronomers. According to the time interval of Ling Xing, astronomers can indeed accurately determine the period of revolution of Kepler 452b-a year is equivalent to 385 days on the earth. Based on this, astronomers can calculate its distance from the star, which is just within the so-called "livable zone". In other words, Kepler 452b, like the earth, is not far from its own sun, so it won't freeze water into ice in cold weather and steam hot water into gas in dry weather. However, even if a planet is in a livable zone, there is no guarantee that there will be water flowing on the surface. The moon is a negative example. What's more, even if there is water, it is still far from life!

Most like the earth?

Kepler 452b cannot be said to be the most Earth-like extrasolar planet. For example, Kepler 186f published in 20 14 has a radius of 1. 17 times that of the earth. Kepler 438b, discovered at the beginning of this year, has a radius of only 1. 12 times that of the earth. These two planets are located in the habitable zone of their respective stars, and are closer to the size of the earth than Kepler 452b. However, the stars surrounded by these two planets are much smaller and darker than the sun. The stars around Kepler 452b are very similar to the sun, only 4% heavier than the sun, 10% bigger and 20% brighter, even if the surface temperature is the same. Therefore, if the stars are taken into account, Kepler 452b will do its duty. It can indeed be called "another earth", but it is still not quite like the earth itself.

Are there more livable planets?

Kepler 452b is neither the only livable planet nor even the most livable planet like Earth. Only 1030 extrasolar planets discovered by Kepler telescope, 12 planets located in the livable zone are between 1 times and 2 times the diameter of the earth. In fact, the main goal of Kepler's mission is not to find "another earth", but to help astronomers better understand how common livable planets like the earth are in the whole galaxy through this sampling survey.

Kepler mission has discovered 12 livable planets with a radius less than twice that of the earth. The planets in the picture are drawn in relative proportion, while the stars are basically reduced by 25 times.

So, fooled by NASA again?

I have been waiting for a long time, but it is such a planet that I don't even know if it is a rocky planet. What about "big news"? What about the agreed "discovery of another earth"? Actually, it's not NASA that is fooling you. On the notice page of NASA's press conference, there has never been "major news" or similar words. The announcement only said that "some new discoveries" made by kepler mission would be announced. As for the discovery of another earth, NASA did mention "another earth" in its notice, but it was "discovery" instead of "discovery" before, okay?

The discovery of Kepler 452b is a step closer to the dream of "discovering another earth". Now, we can wait and see when the real "another earth" will appear. [8]

Can humans emigrate?

The "New Horizon" flying over Pluto is the fastest aircraft in human history. Based on the peak speed of 70,000 ~ 75,000 km/h (equivalent to 19 ~ 20k m/s, greater than third cosmic velocity), it takes 6.84 million years to fly to Kepler 438B and15.84 million years to fly to Kepler 442B. Therefore, in the absence of a breakthrough in interstellar flight theory, it is basically impossible for human beings to reach these exoplanets by relying on traditional rockets and not traveling through time and space. The NASA spacecraft X-43A set a record of 8,000 kilometers per hour, making it the fastest aerodynamic spacecraft in the world. At this rate, it will take 6.5438+89 million years to fly to kepler-452b. This also assumes that the distance between the Earth and kepler-452b has not changed.

The level of human science and technology has advanced by leaps and bounds in the past 100 years, but even relying on this technology, it is impossible to move to another planet. The first thing people should do is to improve the earth environment on which they live, so that we have no reason to go to other planets to survive or reproduce life. The second point is the transformation of nearby-the transformation of Mars. After 2000, human beings can transform Mars into an environment more suitable for human habitation, and because Mars is close to the Earth, it can be used as a sample of living environment. The third point is to move to a planet dozens of light years away from the earth, which depends on the development of human science and technology. It may take a hundred years to improve the level of investigation and research and the exploration of alien life.

In terms of living form, Wang Sichao said that emigrating to another planet is by no means a short-term problem, at least it is impossible for our next eight or nine generations.

There has been a rumor on the Internet since NASA released the news. Many netizens discussed that 1400 light years is not particularly far in theory. According to the theory of relativity, the internal time of a high-speed spacecraft will slow down, so if humans have the opportunity to invent a spacecraft near the speed of light in the future, it will take about 20 years for humans in the spacecraft to fly to the "second earth."

In this regard, Zhu Jin said that this statement is not reliable. Zhu Jin said that judging from the spacecraft manufacturing technology that human beings can realize at present, we are still unable to manufacture spacecraft close to the speed of light. Secondly, the problems related to relativity are complex and profound, and it is difficult to measure them in a specific time. [9- 14]