\u00a9 iStock\/Rastan<\/figcaption><\/figure>\n“Our solar neighbourhood is a dynamic place where stars enter and exit that perfect vantage point to see Earth transit the Sun at a rapid pace,” Faherty commented.<\/p>\n
Seven of these star systems have been identified to host exoplanets \u2013 all with the potential to use similar transit techniques to have discovered Earth.\u00a0 By observing how an exoplanet transits its Sun, the atmosphere can be analysed as it is backlit by the star, meaning alien life as we know it could detect our atmosphere’s chemical signatures of life.<\/p>\n
The most promising contenders<\/h3>\n For example, the Ross 128 system, which is hosted by a red dwarf star situated in the Virgo constellation, is the second-closest system with an Earth-sized exoplanet (1.8 times larger) and round 11 light-years away. Here, any alien occupants would have had a 2,158-year window to observe the Earth’s transit, starting around 3,057 years ago, losing their view around 900 years ago.<\/p>\n
The Trappist-1 system, positioned 11 light-years away, will not be able to enter our transit zone for another 1,642 years; however, they may provide our best opportunity to find alien life when they do. This is because the system hosts seven Earth-sized planets, four of which are within the habitable zone of their host star and will remain in the transit zone for 2,371 years.<\/p>\n
Kaltenegger said: “Our analysis shows that even the closest stars generally spend more than 1,000 years at a vantage point where they can see Earth transit. If we assume the reverse to be true, that provides a healthy timeline for nominal civilisations to identify Earth as an interesting planet.”<\/p>\n
Moving forward, there are numerous space projects aiming to build upon this novel research; the soon to be launched James Webb Space telescope will examine multiple transiting worlds to search for signs of life and to characterise their atmosphere’s and composition. The Breakthrough Starshot initiative will launch nano-sized spacecraft to an exoplanet located 4.2 light-years away located around Proxima Centauri, which will comprehensively analyse the world.<\/p>\n
“One might imagine that worlds beyond Earth that have already detected us are making the same plans for our planet and solar system,” said Faherty. “This catalogue is an intriguing thought experiment for which one of our neighbours might be able to find us.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Astronomers have identified thousands of nearby star systems where alien life as we know it may have already detected humanity.<\/p>\n","protected":false},"author":15,"featured_media":12758,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[771],"tags":[818,24187,3477,809],"acf":[],"yoast_head":"\n
Alien life as we know it may have already discovered Earth<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n