If you could talk to extraterrestrials, what would you tell them? Start mulling over that question, because you'll soon be able to send your very own message into space; a new initiative called Lone Signal promises to be the first continuous, mass experiment in what's known as METI — the controversial practice of Messaging for Extraterrestrial Intelligence. On Monday, the venture will open a web portal allowing anyone to transmit text and photos to distant stars.

"It's never been the case where anyone on the face of the Earth can commune with the cosmos, and we are giving them that ability," Dr. Jacob Haqq Misra, the project's scientific director and an expert in planetary habitability at the Blue Marble Space Institute of Science, said at a press preview of the portal earlier this week. "Anyone can transmit messages to strategically targeted stellar systems."

"How do we, as a species, want to be portrayed?"

Though the premise is out of this world, the actual portal is relatively simple. Users log onto the website, compose their message — the first is free and subsequent notes run 99 cents a pop, with discounts for bulk buyers — and then track its progress through the cosmos. They can also peruse and comment on messages transmitted by other users. "We're basically asking the community to crowdfund this experiment," Ernesto Qualizza, Lone Signal's chief marketing officer, said. "And we hope to see it bring people from different backgrounds and countries together over a common question: How do we, as a species, want to be portrayed?"

The station is best known for transmitting the first images from the Apollo 11 moon landing

They also, of course, hope to see it catalyze a new era of intergalactic communications — one in which humankind manages to detect, and engage with, the intelligent inhabitants of other planets. To make that happen, Lone Signal has secured a 30-year lease of the massive radio dish housed at the Jamesburg Earth Station in Carmel, CA, in order to beam user messages to the heavens. The station, built in the early 1960s, is best known for transmitting the first images from the Apollo 11 moon landing. In recent years, however, Jamesburg has remained vacant: as recently as last year, the 21,000 square foot compound was on sale for $3 million and was being described as "the ultimate man-cave" by its former owner, an electronics mogul who'd hoped to convert the station into a private residence. "This is a wonderful piece of equipment," Haqq-Misra said of the station's 10-story radio telescope. "And it will allow us to reach the kinds of energies necessary for interstellar communication."

That communication will take place using two distinct signals. The first, called a continuous wave carrier, will beam a targeted, long-term "hailing message" to a specified destination. While it does, the Jamesburg dish will beam shorter signals — containing a user's unique message — to that same location. "By sending both carrier [signals], you'll get more attention from anyone watching," Haqq-Misra said. "If they notice the continuous wave signal, they might look more closely at the message carrier.

Lone Signal plans to direct their dish towards a particular star system for around a month before switching to a new interstellar target — all of them, leaders say, will be realms that carry the potential to supporting life. Their first target is Gliese 526, located 17.6 light years from Earth, which means that — if someone out there is listening — we might receive our first response in around 35 years.

"We don't know what the consequences of contact might be, and human history is not reassuring."

And it's that potential response that, for some scientists, transforms this seemingly innocent public project into a decidedly unnerving one. "My basic concern, shared by many other people, is that we have no knowledge of the capabilities or intentions of an alien technological civilization," Dr. Michael Michaud, a retired US diplomat who once served as director of the State Department's Office of Advanced Technology, told The Verge. Though Michaud adds that the odds of Lone Signal actually finding intelligent life are probably low, he notes that "we don't know what the consequences of contact might be, and human history is not reassuring."

Of course, Lone Signal isn't the first METI effort: the Arecibo message, which in 1974 was beamed to a star cluster some 24,000 light years from Earth, and NASA's "Across the Universe" transmission, a lighthearted effort to send the Beatles hit song into space, are two prominent examples. But any discussion of broader efforts has long been dogged by debate among scientists. In 2007, Michaud actually resigned as chairman of the SETI Institute — the largest organized effort to find extraterrestrial life, and one that focuses squarely on passively listening for signals from other planets — because institute leaders were interested in pursuing METI activities. "In my view, that proposal was driven by frustration among SETI people with their lack of success in finding radio signals," Michaud said.

Michaud, along with other former SETI scientists, wants to see robust international consultation before any messages are transmitted into space. "The issue should be discussed in some sort of international body before we expose all of humankind to potential risk," he noted.

"Who are we going to consult with? The UN? The Swedish tennis team?"

Other top tier researchers, however, disagree. "Who are we going to consult with? The UN? The Swedish tennis team?" says Dr. Seth Shostak, an astronomer at the SETI Institute. "There's no harm, and there might be some benefit. This could be a very instructive thing for us to do."

Furthermore, Shostak says, any extraterrestrial life with the technology to receive our signals likely already knows we're here — electromagnetic beams are routinely emitted from televisions and radio broadcasts, for example, and would probably be detectable to those on other planets. "Any society capable of traveling from light years away will be able to pick up signals we've been sending willy-nilly," Shostak explained. "The dog is out of the bag, and a stronger signal doesn't change that situation."