So far, astronomers have found nearly 6,000 alien planets. If the number already feels huge, you should look better. There may be hundreds of people through 외. Billions With our galaxy planet. Some of them will be like Earth. But now we do not know what the fountain is. Nevertheless, because of its total, even small parts can produce many possible planets.
That’s why most scientists take seriously the ideas of life in other worlds. As soon as the Earth had the sea, life was practically quickly. This means that it is easy to start when the condition becomes a class. However, the appearance of dangerous high characteristics such as intelligence and technology is different questions, and we are mostly limited to speculation. There was an interesting investigation). But suppose you are there right now Be Intelligent aliens and technical civilizations somewhere in the Milky Way.
Can they detect us?
To support science journalism
If you are enjoying this article, support the award -winning journalism. accession. By purchasing subscriptions, it will help you to ensure the future of influential stories about finding the world today and the idea of an influential story about ideas.
In that way, in the most common sense, the answer is “yes”. This means that there is no physical reason that could not create a much larger telescope than that of present. Engineering can be significant, but not Technically impossible. For example, it may be a problem to see the city’s lighting at night, such as checking aliens, or aliens. Us, Because we are aliens them-In existence.
It can actually be much easier than that. Much smaller telescopes do not need to solve the planet. It can be enough to observe enough to see the city’s lighting and darker when you rotate and see the city’s lighting at night. And the “smaller” telescope will be overwhelmingly huge instead.
But the reason for this is that the script is overturned in general. we Can detect them, Considering our current technology level. We do not know their level in advance, but we know our own. Therefore, it is reasonable to assume that their skills are equal to us and then ask at a distance at a distance they can discover.
The work is actually very difficult. The space is big, and the huge streets are even darkest of the most powerful civilizations. But we can estimate the external limitations of the interstellar eavesdropping for a small world, which is used as a template and worked back to use similar technologies.
The astronomical team, led by SEOFIA Sheikh of SETI Institute, operated numbers and announced the results. Astronomical journal. (SETI means finding alien intelligence.) The researchers have looked at a variety of ways to detect a variety of so -called technical designation, and the answer is undoubtedly depending on the specific that alien wants. Many of these ideas have previously been investigated individually, but the latest analysis is consistently investigated to reach new insights.
One example of the designation is radio. Since its founding in the mid -20th century seti We focused on detecting artificial wireless signals in space. Wireless wavelengths are easy to create and detect, and can be delivered at the speed of light through interstellar space. Because of this, the radio is made into a almost ideal carrier for galaxy.
Astronomers divided radio signals into four categories. First, the intermittent broadcast is in space, and in essence, “We are here” message; Second, the intentional and continuous targeted signal is sent to the planet probe in the deep space that continues to the Galaxy. Third, continuous entire direction signals such as “leak” emissions of mobile phone tower and radio and television stations; Fourth, signal of artifacts such as low -power downlinks of planetary probes.
Without doubt, the first category signal can be detected at the distant place because it has the highest power related to transmission. Sheikh and her colleagues estimate that these can be found over 12,000 light years on Earth! It is the maximum distance, but there are a few Bilon The star is in the volume. If you want to find, this is probably the way.
Other methods are not lucky. In the second category, the maximum distance is similar to 65 light years and still contains thousands of stars. The third category comes in four years, which is only the closest star to the sun. (The star, PROXIMA CENTAURI, is 4.25 light -years.) Recently, there is a study on wireless discharge of mobile phone tower. The fourth, including a signal of a spaceship, such as Voyager 1 probe, has a detection limit of less than light years. It’s really amazing to see how weak the signal is when the spaceship is about 25 billion kilometers away. Voyager 1’s 23 -watt transmitter Already less than 1 billion won of watts have been faint.As we can see in our world!
Clearly, radio is a choice for aliens looking for the earth. But there is another signature.
One result of our modern civilization is the imprint of our mood. In addition to carbon dioxide, many other chemicals have been abandoned in our air by industrial and other artificial sources. It is not big to change the climate of our earth, but it is not the most speaking, but it can detect signature in space. And the signature can be especially clear for interstellers located along the plane of our solar system, the plane of the earth around the sun. From that point of view, they will see the light slightly darker in front of our stars every year. This is called public transportation and has been the most successful way to discover alien planets.
This transfer can also be used to remotely analyze the air from the world. As the starlight (or in the case of ours) passes through the upper atmosphere of the planet, creates a type of fingerprints that can be measured by the light of a specific wavelength into molecules. We already use James Webb Space Telescope (JWST) to do this for some transting alien planets. Future telescopes, such as NASA’s resident world observation stations, are to scan the atmosphere of alien planets, such as dozens of potential earths that can exist nearby (as seen in the solar system).
In a new study, the Seti Institute astronomer focused on the remote detection of nitrogen dioxide2A noticeable by -product of fossil fuel combustion. Given the current level of contaminated air, they found that they could detect such a signature on the 5.7 light -years. Only Alpha Centauri systems are within that range, limiting the options of aliens to sniffs us. Nevertheless, it is impressive technology achievement that can be performed in this kind of search.
Most different types of technical designation are worse. Somewhere near the Neptune Track, the JWST clone can detect the infrared light of the heat from our city, but the farther trail is cold. At about 100 times the distance, the optical light of the city’s urban lighting will disappear with black.
Lasers are easier to detect and are already being tested in NASA and European space for satellite communication in space. Nevertheless, under reasonable assumptions, the laser concentrated beam of light is too dark to detect the distance of less than six years. It is not enough to be found in Barnard’s STAR and our second star system, Barnard’s STAR.
In the worst case, it includes search for technical artifacts in the world. For example, the flock of artificial satellites on the earth slightly changes the amount of sunlight blocked by the planet during public transportation, but is not enough to detect it in Mars. If an alien gets close enough to see them, there will be a much easier way for them to find us.
All of these numbers come with a fairly warning that aliens are no longer advanced than ours. After all, this can be very conservative because we are always more advanced. We continue to build a larger telescope limited only by budget and physical laws, and we are looking for and developing new ways to investigate the universe, such as detecting neutrino and gravitational waves. We have been working called “modern” astronomy for a century, and it is difficult to predict where it can be 100 years. The galaxy has been around for billions of years. Nobody can tell what uses and others or what they use to explore. truth Be You can best tell you how to find outsiders from the outside.
