American scientists say there are three ways to have encounters with a̳l̳i̳e̳n̳s. H̳u̳m̳a̳n̳s̳ have always wanted to know if we are the only intelligent life in the universe, but according to the observations of scientists, it’s a large potential there are habitable planets in the Milky Way galaxy. That imply the e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ life exists, and to search for e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ intelligence the institute scientists also in different ways and channels to find possible e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ life. Senior astronomer Seth Shostak mentioned at the meeting on May 21, we can search for e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ intelligence by using these three methods.
First method to search for a̳l̳i̳e̳n̳s: To search for e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ microbes or remains after de̳a̳t̳h̳
This survey task used for the exploration of Mars, and NASA has currently deployed named on Mars, the Opportunity of Mar rovers, these two rovers are still land rover platform in continuous observation mission. But Mars is not the only potential life of the planet in our solar system, in fact, many solar systems possess the potential of life, for example, Europa, Ganymede and Titan. Two of Jupiter satellites have the potential to the ocean and Titan has liquid methane lakes, and they will also send a probe to these planets to find traces of a̳l̳i̳e̳n̳ microbes or they were there.
The second method to search for a̳l̳i̳e̳n̳s: Detecting the exoplanets of atmospheric composition
Detect the exoplanets of atmospheric composition, such as oxygen or methane, and also can find the e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ life by detecting the gas generation of life. The outer planets observation technology can already be spectral analysis was carried out on the atmospheric composition, and Seth Shostak thinks that these two methods will be made significant achievements in the next 20 years.
The third method to search for a̳l̳i̳e̳n̳s: Not only for looking for e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ life, but looking for intelligent life
These needs use the advanced radio telescope for a variety of signal on the broader spectrum of the universe analyzing, and the scientists hope to find an a̳l̳i̳e̳n̳ civilization to the cosmic radio signals between intentionally or unintentionally. To find and determine the e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ intelligence signal of civilization is a very difficult work, and the success rate is very low, so far, scientists have searched for almost half a century, there is still no found. This has a lot to do with the scope of our search, we detect the number of stars now less than 1% of the Milky Way, let alone a river of galaxies, Seth Shostak is expected to investigate the millions of solar systems over the next 20 years.