From some exoplanets – bodies outside our solar system, you can see what is happening on Earth.
Lisa Kaltenegger, assistant professor of astronomy at the College of Arts and Sciences and director of the Carl Sagan Cornell Institute, and Joshua Pepper, assistant professor of physics at Lehigh University, have collectively identified 1,004 stars similar to our Sun that may contain Earth-like planets in their own habitat zones. They are all about 300 light-years from Earth.
But what star systems can detect Earth? The ecliptic of the Earth can answer this question. This is the plane of the Earth’s orbit around the Sun. The ecliptic is where the exoplanets that see the Earth will be located as they will be where the Earth crosses its own Sun. So from exoplanets, a view of our planet will open.
Pepper and Kaltenegger created a list of thousands of nearby stars using the NASA Transiting Exoplanet Survey Satellite (TESS) star catalog.
Only a very small fraction of exoplanets will accidentally be aligned with our line of sight. But all the thousands of stars that we identified in our article as being in the vicinity of the Sun could see our Earth passing by the Sun.
Joshua Pepper, assistant professor of physics at Lehigh University