In a new paper, a scientist named Silvano P. Colombano at NASA Ames Research Center stated that Earth may have already been visited by extraterrestrials, but humans may not have noticed.

He suggests that intelligent life may not be what we are used to and may not necessarily use the traditional building blocks of that humanity is accustomed to, such as carbon.

According to him, scientists must revisit our most cherished assumptions and consider the idea of different characteristics as well as the possibility that interstellar travel is already feasible for extraterrestrials.

In the paper, he wrote, “I simply want to point out the fact that the intelligence we might find and that might choose to find us (if it hasn’t already) might not be at all be produced by carbon-based organisms like us.”

“So if extraterrestrials are not carbon-based, what does that do to our assumptions about what to look for? Well, a lot.”

“Our typical life-spans would no longer be a limitation (although even these could be dealt with multi-generational missions or suspended animation), and the size of the ‘explorer’ might be that of an extremely tiny super-intelligent entity.”

He also noted that the alien life may have made sense of the technology that people can not fathom yet, making assignments, for example, interstellar travel conceivable. On the off chance that we receive another set of assumptions about what types of higher intelligence and innovation we may find, a portion of those marvels may fit explicit theories, and we could begin some genuine inquiry.

In any case, the researcher surrenders that interstellar travel could be an unbreakable barrier over ranges of thousands of years, however, he included that interstellar adventure could be conceivable relying upon what we expect about different types of life.

Colombano explained, “Considering further that technological development in our civilization started only about 10K years ago and has seen the rise of scientific methodologies only in the past 500 years, we can surmise that we might have a real problem in predicting technological evolution even for the next thousand years, let alone 6 Million times that amount!”