NASA astronaut explains why he think aliens have never visited Earth

A NASA astronaut who believes life in outer space is ‘very likely’ has explained why he thinks aliens have never visited Earth. 

Having experienced much more of the cosmos than other mere mortals, Love has had plenty of time to reflect on the big questions about just what is out there – saying he thinks alien lifeforms are highly probable. 

"As soon as the surface was cool enough for liquid water to form. So 3.5 to 3.7 billion years ago. But for 3.2 billion years of that it was green slime in the oceans and it was not little green men in flying saucers.” 

However, Love said he wasn’t convinced that aliens had visited Earth, claiming their spacecraft would likely burn part of the planet as it flew off – leaving quite a clear trace of their trip.

Saying the situation is probably a far cry from the sci-fi tropes we've become accustomed to, he continued: "I am strongly sceptical of the idea that intelligent life is coming here and mutilating cattle and, you know, teasing people out on the roads if you’ve read Hitchhiker's Guide to the Galaxy. 

"Yeah, no. The amount of energy it takes to travel between the stars, within the laws of physics as we know them, and we’ve been exploring those laws very thoroughly and haven’t found many holes lately, is something like 100,000 times the annual energy consumption of the planet Earth." 

Love added: "Ask anyone from the Middle East, energy is wealth. So, at the time when the Earth is 100,000 times wealthier than it is now, we might be ready to send the mission to another star. 

"And, if you are going to expand that kind of energy. No matter how much power you wield, you’re not going to mess with cows when you get there. I’m highly sceptical. 

"Show me the evidence and I’ll believe it."