Why Interstellar Visitors May Remain Unseen: Distance, Energy, and Earth's Biosphere
To the point
Despite Steven Spielberg’s film and polls suggesting we’re not alone, interstellar visitors are unlikely to reach Earth because space is vast, near-light travel would require impossible energy and runs into physics limits, and Earth’s oxygen-rich biosphere would be hazardous to outsiders, though thousands of exoplanets exist and searches like SETI continue for life elsewhere.
