When you think of Earth's twin brother, who comes to mind first? Is it Venus, which was once expected by scientists, but has been disfigured by reality, or is it Mars, which is now in the limelight?

In fact, there are planets in the universe that look more like Earth than they do, and that is Kepler-452b, which was once discovered by NASA.

It is said that the Earth's "twin brother", may not only have mountains and water, the time of the year is also very close to the Earth, about 385 days. So, since it is so similar, does it mean that life may exist here?

How was the Earth's "twin brother" discovered?

Humans know that the Earth's resources are limited, so if human civilization wants to continue, it must plan for its future early. For example, when the Earth is uninhabitable, humans have to choose to migrate to other planets. In the case of the solar system is still safe, this migration will only be carried out inside the solar system, so Mars has become the first choice now.

However, if something changes in the sun in the future, mankind can no longer cling to the solar system, but to find a habitable planet beyond the solar system. Although from the current development of technology, we fly out of the solar system are very difficult, but it is difficult to say where the human footprint can go after a few more "technological explosion".

So no matter what the future holds, first we have to search for habitable planets as an alternative. Over the years, humans have indeed found many "super Earths", one of the more famous of which is probably Kepler-452b, which was discovered by the Kepler Space Telescope in the United States.

NASA announced their discovery of Kepler-452b back in 2015, noting that this guy is located in the constellation Cygnus, with a distance of about 1,400 light years between him and Earth.

The reason for singling out this discovery is that Kepler-452b is so similar to Earth and was once considered the most similar exoplanet to Earth discovered by humans to date.

So, what exactly are the similarities between Kepler-452b and Earth? Why is this planet so similar to our Earth?

The unique Kepler-452b

Because there are so many objects in the universe, human exploration of habitable planets cannot be a "fly-by-night" exercise, but rather an observation of only planets in the "habitable zone". For example, the Earth is in the habitable zone, and the distance between it and the Sun is just right to have a stable and suitable temperature.

Kepler-452b is just like Earth in this respect, because first of all, the star in its galaxy is very similar to our Sun, which is 1.5 billion years older and emits about 10% more light than the Sun.

Second, the distance between Kepler-452b and its galaxy stars is also very similar to that of the Earth, in which case it takes about 385 days to make one revolution, which is very similar to the 365 days of the Earth. This distance, which is very favorable for the formation of liquid water, has led some scientists to speculate that this planet may have mountains as well as water, just like Earth.

"Water is the source of life, according to the experience of the evolution of life on Earth, with water it is possible to nurture life, the ecosystem can evolve, otherwise intelligent life can not reproduce. The presence or absence of liquid water is a prerequisite for scientists to speculate whether life exists outside the earth." Zheng Yongchun, an associate researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, said.

Of course, although the similarity index between Kepler-452b and Earth is as high as 0.98, it is not a twin to us after all, so there are still differences in some aspects.

For example, this planet is larger than the Earth, and this large is not only about the size, but also in age. According to scientists speculation, Kepler-452b should have been 6 billion years old and about 60% larger in size than the Earth.

It is worth mentioning that since the Kepler Space Telescope adopted the "lensing method" to detect Venus, we can only deduce its diameter, but not its mass and density.

If we find out that Kepler-452b is not a rocky planet when we get up close and personal, then the so-called "twin brother" will not exist. In addition, some scientists believe that we sometimes think of this planet too idealistically, just as we once did with Venus.

Without knowing the thickness and composition of the atmosphere, it is difficult to say whether this Earth's "twin" is also plagued by the greenhouse effect and the surface is very hot.

Overall, although we are expecting Kepler-452b, it is best not to treat it as a complete replacement for Earth in the short term, or we will inevitably feel disappointed when the truth is revealed.

However, scientists believe that as long as the environment is not as outrageous as Venus, then the planet should still be considered relatively habitable, and there may even be life on it.

Could there be aliens on Kepler-452b?

Mankind has always seemed obsessed with the search for extraterrestrial civilizations, and scientists are even more excited to meet such planets that are very similar to Earth, and are very excited about it.

So, could there really be aliens here?

Scientists have always believed that life cannot be born only on Earth in the universe, so if we look at the conditions for the emergence of carbon-based life, Kepler-452b should still fit the bill.

Of course, this requires that liquid water still exists on its surface, and not just traces of water left behind over time, as on Venus or Mars. In addition to this, the magnetic field and atmospheric conditions of Kepler-452b are also crucial, which means whether it can help the organisms living in it to withstand cosmic radiation.

And if it really is very similar to the Earth in every way, it may show us what the Earth will look like in the future if it is 1.5 billion years older than the Earth. It could be a deteriorating ecology, or it could be a vibrant view of everything pushed back.

As for whether there will be aliens living up there or not, it needs to be followed up by continuous probing to come up with an answer. But then, if conditions permit, scientists may send a signal toward the Earth's "twin", if the response, it means that there is indeed life born here, and even the development of civilization.

In any case, everyone is still very excited about the "life" on Kepler-452b, and it will not be the last habitable planet that humans find, and human plans for a large search area are still underway.

One might wonder, if Kepler-452b is really like Earth, with a complete and healthy ecosystem, is there any way for us to live here in the future? After all, from the environmental point of view alone, this planet may be in much better condition than Mars.

Can humans fly across light years to Kepler-452b?

As we mentioned in the previous article, the distance between Kepler-452b and Earth is up to 1400 light years, which is undoubtedly astronomical for humans. Therefore, most scientists believe that before finding a "wormhole" such as a channel, humans want to reach here is impossible.

Some people may think that 1400 is not a big number, but it should be noted that the unit here is "light years". The analogy has been used to illustrate the distance between the Earth and it, stating that if we use a high-speed rail at 300 km/h as a carrier, it would take about 5 billion years to reach Kepler-452b.

It may take 200 million generations to complete this journey if we want to rely on the continuation of life.

Of course, we still have to dream, in case a hundred years later mankind has achieved great success in this area. From the current point of view, the most important thing is to give the ship a speed boost, after all, if the current turtle speed, then want to cross light years is not possible.

Previously, some scientists believe that when humans can use antimatter as fuel for rockets, our interstellar journey will really come. Until then we can only move forward step by step to open the way for our children and grandchildren to ensure that they will be closer to their dreams.

After discovering Earth's twin planet, the first step we thought of was always to find out if we were alone," a NASA spokesman said in response to a reporter's question about Kepler-452b. While it may not be possible for us to travel to these planets, our descendants will."