Boffins have revealed that aliens could be avoiding Earth because they are terrified of a bizarre cosmic 'time curse' that would turn them into outcasts. Space enthusiasts have long pondered why extraterrestrials have not visited, with interest peaking after the US government released hundreds of classified UFO documents and the launch of Steven Spielberg's new film, Disclosure Day.
The Time Curse Explained
According to Carol Oliver, Professor in Science Communication and Astrobiology at the University of New South Wales in Sydney, any alien brave enough to fly to Earth at near-light speed would return home to find everyone they knew dead. Writing in The Conversation, Professor Oliver explained that Albert Einstein's theories dictate time slows down the faster you move through the cosmos. While this sounds like a neat trick, it creates a heartbreaking reality for deep-space travellers.
She said: "They would go home to a planet much older than the one they left – perhaps by a century or more. They would be time exiles." This mind-boggling phenomenon, known as time dilation, has been proven by astronauts. When NASA astronaut Scott Kelly spent a year orbiting the planet on the International Space Station, he aged slower than his identical twin brother on Earth. Professor Oliver noted: "He was milliseconds younger than his identical twin because time moves more slowly for objects in motion."
Interstellar Travel Challenges
While a few milliseconds may not cause family issues, the stakes are vastly higher for aliens. Because space is so vast, any interstellar journey requires significant speeds. Earth's closest stellar neighbour, Proxima Centauri, is 40 trillion kilometres away. The fastest spacecraft, the Parker Solar Probe, maxes out at 191 kilometres per second, which would take 6,650 years to reach that star. To get to Earth within a normal lifespan, aliens would need to fly at near the speed of light, warping time so severely that their home planet would fast-forward by hundreds of years.
If being a lonely time exile were not enough, the journey itself is a death trap. Travelling at near-light speed turns tiny, harmless floating hydrogen atoms into deadly, intense radiation. The friction would generate immense cosmic heat, which would "ablate and eventually destroy the hull" of any flying saucer, according to Professor Oliver.
Earth's Atmosphere a Threat
Even if aliens survived the trip, cracked the time curse, and parked on Earth, the air could melt their faces off. Earth's oxygen-rich atmosphere, produced 2.4 billion years ago by cyanobacteria, is perfect for humans but potentially lethal to visitors. Professor Oliver said: "It's therefore not toxic for us, but oxygen is reactive and could be highly corrosive for aliens." She added that while they could wear protective gear, "reports of visiting aliens do not include any descriptions of spacesuits."
Despite these challenges, experts have spotted 6,200 exoplanets across 4,700 solar systems. With over 100 billion stars in our galaxy alone, the mathematical odds of life out there remain significant.
