Earth scientists may someday turn on a high-powered megawatt-class laser beam pointed towards deep space.
James Clark, a graduate student of MIT’s Department of Aeronautics and Astronautics, wrote a feasibility study in the Astrophysical Journal, where he describes using a laser beam as a “planetary beacon,” which could be seen 20,000 light-years away.
Clark is also the author of a new MIT report.
The MIT report/study proposes how “laser technology on Earth, could, in principle, be fashioned into something of a planetary porch light.”
Transmitting a 1- to 2-megawatt laser beam strong enough not to be obscured by the sun’s radiation and seen light-years away would require a telescope nearly 148 feet in diameter.
Clark suggests “extraterrestrial astronomers” living on planets in the neighborhood of Proxima Centauri (the nearest star to Earth), would be able to detect a linear laser beam originating from Earth.
I assume an extraterrestrial astronomer; who just happened to be looking at the Milky Way Galaxy through a telescope, might wonder what the straight line of light was all about.
Just an FYI: as of 2017, the known universe contains at least 2 trillion galaxies.
Do we really want to send a high-powered laser beam into outer space to signal extraterrestrial intelligence, and let them know where we are located?
What if this guiding light/laser beam is seen by a technically-advanced civilization that decides to pay us an interplanetary visit?
I am reminded of a few science fiction movies where aliens come to visit us.
As I recall, the aliens (except for the Vulcans) were not very friendly to the folks living on Earth.
February 2017, NASA announced its Spitzer Space Telescope discovered a star 40 light-years (235 trillion miles) away in the constellation Aquarius.
This star has seven exoplanets orbiting it.
This exoplanetary system is called TRAPPIST-1, and is named for The Transiting Planets and Planetesimals Small Telescope, located in Chile.
Three of the exoplanets were determined to have the potential to support life.
March 30, 2021, NASA is scheduled to launch the James Webb Space Telescope (JWST) to replace the aging Hubble Telescope, launched in 1990.
The JWST is a new and much more powerful telescope than the Hubble. It will be able to gather in-depth information about the exoplanets atmospheres, including carbon dioxide, methane, water, and oxygen.
It has been suggested, if astronomers on Earth ever did detect a light-signal originating from one of these three planets, we could use a high-powered mega-watt laser to send controlled pulses of light a visual Morse code, or signal lamp if you will, to the exoplanet.
Earth would send a message, hope it would be understood, and then wait for a message to be sent back.
What will be the message Earth sends to intelligent lifeforms living on another planet?
Shouldn’t we, at this stage of our social and technological development, consider the consequences of contacting what is likely a more advanced and possibly aggressive extraterrestrial civilization?
Then again, maybe the extraterrestrials will only want to learn how we brew our coffee.
“If we were to successfully close a handshake and start to communicate, we could flash a message, at a data rate of about a few hundred bits per second, which would get there in just a few years,” said James Clark.
“I’m sure the universe is full of intelligent life. It’s just been too intelligent to come here,” said science fiction writer Arthur C. Clarke in 1996.
On the other hand, maybe they are intelligent enough to first send an information-gathering space probe through our solar system.
Last October, scientists, using the PANN-STARRS 1 space telescope on Mount Haleakala in Maui, HI, identified an unusual cigar-shaped object which was not a comet, meteor, or asteroid.
The one-quarter-mile-long space object traveled through our solar system and passed by the Earth at speeds of up to 196,000 miles per hour.
The object was named ‘Oumuamua, meaning messenger, or scout, in Hawaiian.
‘Oumuamua is the first object of interstellar origin to be observed in our solar system.
Nov. 1, researchers at the Harvard Smithsonian Center for Astrophysics released a five-page paper about ‘Oumuamua.
The paper surprisingly reveals “the possibility that it [the space object] might be a ‘light sail’ of artificial origin.”
A light sail/solar sail would be used to gather solar energy to power . . . what?
Harvard’s astronomy department’s chair, Avi Loeb, suggested the object is a light sail to propel an interstellar traveling alien spacecraft using solar energy.
“Considering an artificial origin, one possibility is that ‘Oumuamua is a light sail, floating in interstellar space as debris from advanced technological equipment,” according to the Harvard paper.
I have read the Harvard paper, and it shows many mathematical and scientific formulas to support its claims that the space object is of artificial origin.
The Harvard Smithsonian Center for Astrophysics paper can be read at https://arxiv.org/pdf/1810.11490.pdf.
Since ‘Oumuamua has traveled beyond our solar system, it is now too far away for telescopes to photograph it.
‘Oumuamua has also voyaged beyond the range of our space rockets’ ability to chase it down.
For now, we patiently observe space using our current telescopes, and wait until the JWST is available in 2021.
Someday, another ‘Oumuamua will be seen. Hopefully, scientists will have the technologies needed to understand the composition, purpose, and origin of that interstellar visitor.
We also continue to debate whether Earth should send a high-powered laser beam into outer space to signal any extraterrestrial intelligence of our existence.
Like the Motel 6 commercial, where they leave the light on for us, Earth may soon be leaving its light on for the universe.