The quest for extraterrestrial life is easily one of the most fascinating facets of science – and also one of the most controversial.
With every technological advance made in the science industry, more and more experts are speaking out about what exactly might or might not be in the realm of possibility when it comes to alien lifeforms.
Even the National Academy of Sciences (NSA) has said in the past that communicating with other civilizations “is no longer something beyond our dreams but a natural event in the history of mankind that will perhaps occur in the lifetime of many of us,” according to a paper published on the NSA’s website.
The paper noted that acclaimed radio astronomer Sir Bernard Lovell once posited that out of the 100 million stars in our galaxy, “there must be planets of the right chemistry, dimensions, and temperature to support organic evolution.”
And when one takes into consideration that our galaxy is but one of a billion others in the universe, chances are we are not alone – at least according to the late Cornell University astronomer and one of SETI’s first leading researchers Dr. Frank D. Drake.
Still, if there is some fact behind that idea, then the question, famously posed by physicist Enrico Fermi, begs: Where is everybody?
For more than 60 years, scientists, with the help of organizations like SETI (Search for ExtraTerrestrial Intelligence) have been scouring deep space with radio telescopes, but have so far found nothing.
According to experts, nearby stars Epsilon Eridani and Tau Ceti (about 11 light-years away), are the most habitable for harboring extraterrestrial life.
Nonetheless, our nearest alien neighbors would likely be at least 100 light-years away and it would take something like seven generations to receive a message from them, according to the NSA paper.
That is, assuming the alien civilizations have not (1) given up on contacting us; (2) already reached out thousands of years ago and are awaiting a response; or (3) died off due to any number of crises, according to Professor Iosif Shklovsky, Russia’s greatest radio astronomer.
With that said, if none of the aforementioned scenarios apply and intelligent life is indeed out there, here is how experts believe they might reach out to Earthlings.
As far as scientists know, repetitive laser pulses may be the most promising method for detecting alien life because its quick and can travel across vast distances.
Due to those reasons, scientists are not ruling out that aliens might be using a similar method to try to contact us, or other civilizations.
SETI is currently testing this method via its LaserSETI project but so far, there has been no sign of alien life.
Some researchers have toyed with the idea that incredibly advanced civilizations may possess the capabilities to move stars into strange or highly geometric alignments that could alert us of their presence, according to David Grinspoon, an astrobiologist at the Planetary Science Institute, per Live Science.
“They could construct something that would be visible from a huge distance across the galaxy, or even from another galaxy, that would be obviously artificial,” Grinspoon said.
Some researchers have argued that alien megastructures could act as giant “look over here” signs that direct outside civilizations towards them, Grinspoon said.
Of recent interest to scientists was the star KIC 8462852, which has inexplicably dimmed and brightened over the past several years.
Some researchers have argued that perhaps the star is surrounded by an alien megastructure that is blocking light from the star, however, it might also just be occasionally obstructed by exoplanets.
Radio waves have been Earth scientists’ method for searching for alien life for nearly 100 years.
Because radio waves can travel seamlessly through the universe, they are ideal for communication, at least according to humans.
Still, many scientists have argued that extraterrestrial life may be resorting to the same medium.
Of course, this is assuming that aliens not only think like us but possess the same technology.