The famous equation used to search for extraterrestrial civilizations has inspired a new formula for hunting extraterrestrial artifacts within the solar system. The search for these extraterrestrial artifacts begins with the moon and other near-Earth objects. 

Drake’s equation is used to estimate the number of extraterrestrial civilizations that can be detected by radio signals in the Milky Way or the probability of finding intelligent life in the galaxy. 

In 1961,  radio astronomer Frank Drake first proposed this equation. The equation calculates the number of communication civilizations by analyzing various variables such as the rate at which stars are formed suitable for the growth of intelligent life and the number of habitable planets per star system.

At present, SETI (Search for Extraterrestrial Intelligence) experiments in search of optical and radio signals are dedicated to the study of the skies; In recent years, however, some researchers have suggested a better way to find extraterrestrial life.

 Instead of searching for radio signals, they refer to hunting for traces and messages in bottles or SETA, which stands for search for extraterrestrial artifacts.

 For example, researchers in 2004 proved that signal distribution throughout the universe is costly and inefficient. According to their calculations, leaving a message in a large mass of matter and placing it in potential points for extraterrestrial friends requires one trillionth of energy compared to the previous method.

Another concern with SETI is that extraterrestrial civilizations may have been extinct long before the signal was received. Extraterrestrial artifacts can provide a way to learn directly about extraterrestrial civilizations , according to James Benford , a microwave physicist in Lafayette, California. Especially if these artifacts are equipped with artificial intelligence.

 In a new study, he developed a version of Drake’s equation for artifacts. The new formula focuses on “secret observers”. From Benford’s point of view, secret observers are robotic and secret extraterrestrial probes.

 Although the developing civilizations of these observers may be extinct, the observers themselves are active in communicating with us.

The main difference between SETA strategy and conventional SETI methods is that SETA actively seeks evidence rather than anonymous observations. 

According to Benford, the SETI community needs to reconsider its approach. By comparing the new formula with Drake’s equation, he shows the percentage of potential success of SETA compared to conventional SETI.

For example, if an extraterrestrial civilization considers the production of artifacts to be more efficient than the production of radio signals, the SETA method will be more successful than the conventional SETI.

Conversely, if there is an extraterrestrial civilization similar to ours that can only send spacecraft at interplanetary speeds, it may produce signals instead of interstellar probes.

In this case, SETI will be more successful than SETA.

Extraterrestrial civilizations that have passed close to the Sun are probably interested in launching a probe into the solar system.

 According to Benford, almost every million years, two stars are one light-year away, and every fifty thousand years, one star is ten light-years away from the solar system. 

The closest collision of the solar system was with the star Scholes, which was about seventy thousand years ago at a distance of 0.82 light years from the Sun. Benford says:

Over a period of tens of thousands of years of agricultural civilizations on Earth, almost two stars were located ten light-years away … NASA’s lunar reconnaissance orbiter has recorded two million images of the moon since 2009 with a resolution of 0.3 meters. You can see the traces of Neil Armstrong in some pictures; But only a collection of these images are spectacular to the human eye. We need artificial intelligence software to examine structures, including artificial signs.

In addition, Benford suggests searching for extraterrestrial artifacts located in other near-Earth objects. These objects include Trojan objects (located at the point of gravitational equilibrium of the Earth and the Sun) and objects in orbit around the Earth. Benford states:

China is planning for the Genghis Khan mission. The mission aims to study Earth’s orbital objects, including 2016 HO3, which will be launched in 2024. 2016 HO 3 is ten times the distance from Earth to the Moon … If a long time has passed since the existence of artifacts on Earth, it will certainly be exposed to weather, damage, theft or erosion that will not be discovered for hundreds or thousands or millions of years; But in a place like the moon, it remains intact even after thousands of years. In general, by searching close to the ground, we can answer “yes” or “no” to part of the SETI question and perform experiments to get the answer, and not just wait for the signal. SETI asks: Where are they? Well, they may be around.

Details of his findings were published online March 18 in the journal  Astrobiology . He debated his idea with Breakthrough Listen, a decade-long, $ 100 million search for intelligent life in the world, and in 2015, renowned scientist Stephen Hawking introduced it to other researchers.