The existence of aliens is a widely-discussed debate that’s been going on for decades. Helen Sharma, the UK’s first astronaut, believes without a doubt that aliens exist and that they are already living on Earth — undetected.
“There are so many billions of stars out there in the universe that there must be all sorts of different forms of life,” she said in an interview. “It’s possible they’re here right now and we simply can’t see them.”
Think it’s impossible? An astrobiologist weighed on in this matter and you’d be surprised at what they had to say…
Microscopic Shadow Biospheres
Samantha Rolfe of the University of Hertfordshire’s Bayfordbury Observatory wrote in her article that if aliens do exist as Sharma claims, they are most likely undiscovered creatures with different biochemistry. This different biological makeup could be the reason why these aliens are invisible to our human eyes.
“This may mean that there could indeed be many lifeforms we haven’t yet spotted. We do now have the ability to sequence the DNA of unculturable strains of microbes, but this can only detect life as we know it – that contain DNA.”
Different Biochemistries or Different Origins?
Humans and most other lifeforms we can recognize are carbon-based but there is a chance that the ‘aliens’ we are looking for are made from other materials. Around 90% of Earth is composed of silicon, iron, magnesium, and oxygen so there are many different ways that life can be formed.
One of the leading contenders for this theory is silicon but it is actually an element heavier than carbon, making it difficult for it to form strong bonds. There is a possibility that silicon can form life by combining it with carbon however, this is a theory that is being challenged.
Rolfe muses that “if there were viable silicon lifeforms here, they may have evolved elsewhere.” It’s quite likely that if there are living organisms discovered with different chemical makeup that they came to Earth from other planets or meteorites… just like how carbon-based life is believed to have arrived!
What do you think?