Aliens, if they do exist, are only robotic probes

The search for Extraterrestrial Intelligence (SETI) program began in 1959, and modern UFO observations date back to the late 1940s. Although they look similar, there is actually no connection between the two. SETI programs generally require a graduate degree in astronomy, and scientists in the field tend to have little regard for UFO enthusiasts, who are seen as incapable of anything more than taking a few blurry pictures with their cameras.
Now, however, the two camps are moving closer.
According to classic SETI theory, when scientists look at stars, they mainly rely on man-made signals to determine the existence of alien civilizations. But from an alien point of view, this form of communication has serious flaws. To communicate successfully, aliens would need to target millions of nearby stars, including Earth, and send signals continuously over hundreds of millions of years. In addition, they prepare a special receiver for each target star so they don’t miss the message. The time, energy and material costs involved in this communication strategy are incalculable. Not only that, if the rashly announced their existence to the outside world, but also may attract some aggressive civilization, to bring their own disaster. Plus, they don’t know anything about other civilizations. Perhaps other civilizations communicated by color changes like cuttlefish, while recipients communicated by “dance” movements like bees.
Building on other research, author John Gertz has suggested that for aliens to contact other civilizations, it would be best to use robotic probes. These simpler fly-by probes might monitor the nascent star system periodically (say, every 200 million years). Star systems that show signs of life may be monitored more frequently. More powerful probes could stay permanently near planets with multicellular life.
When the stationary detectors detect artificial electromagnetic signals, they suggest that multicellular life on the planet has evolved into a technological civilization, and then try to analyze that species. Of course, it will take time for them to fully decipher the language, science, mathematics and culture of Homo sapiens. We’ve been studying ant communication for decades, but we’re still a long way from cracking it. It would be much harder for aliens to completely crack human civilization.
The probes may need to send data back to their home stars for further analysis, or wait for further instructions. Suppose a probe began transmitting data to its home star in 1950 after it first detected television signals from Earth, and came within a modest distance (within 150 light years), then it would have to wait 2250 years to receive instructions from its home star.
But when nearby alien probes decipher Earth’s civilization and make contact with us, we’ll be able to communicate with it in our own language. Instead of waiting for signals to travel back and forth between Earth and an alien planet hundreds of light years away, these conversations can take place almost in real time. Alien probes also don’t need to reveal the location of their home star to us, so they don’t pose a threat to themselves. Fully autonomous probes could continue to communicate with us even after the extinction of their home civilization.
Assuming that a probe belongs to an existing civilization, communication between the two is also a problem. To communicate directly, a transmitter would have to be quite large. A better solution might be to set up a series of communication nodes, such as one in each star’s orbit. Each node must be sufficiently distant from the star to use the star as a gravitational lens. For example, at the sun’s focal point, about 550 astronomical units (the distance from the Earth to the Sun), the signal received by the communication node could be a billion times stronger.
Many alien civilizations could contribute to this communication node system. Whether these civilizations survive or die out, the amount of information stored in these systems will increase over time. We could also add Aristotle, Shakespeare, Beethoven and Monet to the encyclopaedia of the Universe. But if alien civilizations have been monitoring our TV and Internet for more than 70 years, they would probably have uploaded the information they wanted into the system. But alien civilizations might also want us to join the galaxy club, so we might need to build probes and communication nodes, or maintain interplanetary communication systems around Earth. This could be a bargaining chip with alien civilizations.
When SETI observations are made, if the signal is very weak, it must be detected with the most powerful telescopes on Earth. Sensitive telescopes, however, have a very narrow field of view. But to detect an alien probe near Earth requires the opposite strategy. Because these probes are so close to Earth, they will appear bright enough to reach several watts, even by the most conservative estimates. When observing these detectors, SETI will need to reduce the sensitivity of the telescope in exchange for a wider field of view, or even an all-sky, all-weather observation. Some organizations are already building or preparing for such systems.
While those so-called “Ufos” may have been illusions or rumors, many SETI scientists today are beginning to agree with UFO enthusiasts that our first real detection of aliens may have occurred within the solar system. Both sides should also agree that if the so-called Ufos we observe are truly alien, they must be robotic probes, not starships carrying alien life. Otherwise the creatures would have been crushed to pieces by the tremendous acceleration.
Of course, there is not enough evidence to really unite UFO enthusiasts with SETI scientists. But the gulf between the two camps may not be so wide as to be unbridgeable.