In 2014, a meteorite entered Earth’s atmosphere and exploded mid-air over the ocean near the Pacific island nation of Papua New Guinea, presumably scattering small pieces on the ocean floor. Meteors that burn up in the atmosphere and leave tiny trails are not uncommon — NASA Estimate Nearly 50 tons of space rocks fall to Earth every day. However, Harvard University astrophysicist Abi Leob suggests that this particular meteor, called CNEOS 2014-01-08 or IM1, may actually be part of an alien spacecraft. It became a hot topic recently.
Many of Loeb’s colleagues in the fields of astrophysics and the Search for Extraterrestrial Life (SETI) are highly skeptical of his claims. They also question the evidence from CNEOS 2014-01-08. really interstellar object. But Loeb’s allegations and their criticism raise important questions. How do we know if we have found evidence of extraterrestrial life when the data is often so small, so far away, or just plain vague? And how do you share your discoveries?
“That’s a big problem.” Jason Wright, Professor of Astronomy at Pennsylvania State University. “SETI calls these post-detection protocols.”
Scientists working on SETI in the 1960s and 1970s, such as Carl Sagan and Frank Drake in the United States and Nikolai Kardashev and Joseph Shklovsky in the Soviet Union, wondered how to identify potential radio signals of extraterrestrial origin. A set of protocols was developed to assess how
The first step was to keep the claims to a small group. “When he thinks he might have found something, he can only share it with other scientists without making it public,” he says. It may sound “incredibly simple now,” he notes, but it made sense even before the internet. After he analyzed the signals and made sure he wasn’t confusing Earth’s radio signals with aliens, he said, “Then we’re going to make a big announcement. We’re going to the United Nations, we’re going to go to governments. ”
What Cold War-era SETI post-detection protocols did not anticipate, Wright said, were more ambiguous signals and evidence. But they started already in his 1970s, with a series of experiments on his NASA Viking mission to Mars.
The experiment was intended to detect the presence of organic compounds and possibly extraterrestrial life on Mars, but yielded unclear and contradictory results.biological experiments on Viking 1 The probe showed one positive result, one negative result, and a third unknown result for the presence of organic compounds. The experiment’s lead scientist, the late Gilbert Levin, who died in 2021, recently claimed: as 2012 This experiment actually found traces of life on Mars.
And in 1996, a team of scientists at NASA’s Johnson Space Center, led by David McKay, began investigating a Martian meteorite known as Allan Hills 84001. Team members became convinced that they had found fossil evidence of life on Mars in this universe. It’s great that it reached President Bill Clinton. who said “It speaks of the possibility of life” in an address to the nation.
The scientific community has come to believe that McKay and his team were wrong, but they ‘had a reasonable responsibility’ [in the first article they published about it]Even if they clearly believed they had something.” Arizona State University Astrophysicist Stephen Desch Say.
Since its publication in 1996, scientists have further explored how to measure the level of evidence for signs of extraterrestrial life in a variety of settings. On the European Space Agency’s ExoMars mission, the Rosalind Franklin rover, scheduled to launch to Mars in 2028, will use the complex.biosignature score‘ rubric, which ranks the confidence that the experiment found signs of aliens.
The key to evaluating evidence for extraterrestrial life is understanding what the confounders are, Wright said. In other words, what could be mistaken for what you’re looking for?
For astronomers looking for signs of alien telecommunications, if you want to eavesdrop on alien radios, you need to rule out radiation signals from Earth. “If you do a SETI search these days, you’ll get millions of hits, calls, and detections, all from terrestrial transmitters,” Wright said. “It’s very hard to leave them out to get rid of them. It’s like being in a crowded room and everyone talking at the same time and trying to hear the only voice.”
In the case of signs of technological origin, or signs of fossilized life in meteorites, confounding factors are processes that may produce those objects without appeal to extraterrestrial life. Most scientists ultimately concluded that what appeared to be fossil microbial life in Allan Hills 84001 may have been produced by other chemical or geological processes.
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Off the coast of Papua New Guinea, Loeb and his team used magnetic sleds to drag the ocean floor along the expected trajectory of space rocks. They collected small metal balls. (Island authorities) suggested that the material may have been obtained illegally.) The astronomer in his announcement blog His team said they had recovered a rare magnetic material consisting of an alloy of iron, titanium and magnesium, which he said “doesn’t resemble any known man-made alloys or familiar asteroids.” He asked if the asteroid was manufactured by some alien technology.
But it also needs to be ruled out that these globules didn’t originate from many other sources that produce tiny metal flakes on the ocean floor, SETI experts say.
“We need to check them against the more mundane possibilities involving spherules from. [non-intersterstellar] Asteroid material is hitting the Earth,” Desch said, noting that the ocean floor is covered with small fragments of regular meteorites. Then there’s volcanic ash and man-made globules, “which come from coal-fired power plants and fall to the ocean floor.”
And it’s also important to get control samples, the most important form of comparison in science, while comparing possible signs of life to more mundane substitutes.For example, since landing on Mars in 2021, NASA’s Perseverance The rover is collecting rock and soil tubes that will be returned to Earth for analysis in the early 2030s.
To ensure that the traces of life are not actually contamination brought to Mars from Earth, the rover is equipped with five “”.witness tube‘ contains terrestrial material that could theoretically contaminate the rover’s samples. A simple opening of a Martian sighting tube will allow scientists to learn patterns about how Martian samples undergo contamination on Earth.
Desch says similar measurements are even easier to make when searching the ocean floor for evidence of interstellar meteorites. “Let’s go 100 miles away and collect things from there and see if there’s anything different,” he says. “If you see the same thing mixed everywhere, it’s all natural, not alien.”
Loeb said he believes the spheres the team found are indeed from a meteorite and not from any other source. “The composition of globules along the meteor’s path differs from that of volcanic ash,” he wrote in an email. popular science. “Our control sample was taken tens of kilometers from the meteor track and revealed a large number of globules at a tenth of the way from the meteor track.”
Loeb plans to conduct further laboratory analysis of the recovered material at the Harvard University Observatory. If history is to be any guide, its analysis must be very thorough. Because so far, identifying vague signatures of extraterrestrial life has proven to be an ambitious and incomplete task.
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But that doesn’t mean there aren’t conditions that would definitively indicate the existence of extraterrestrial life. If intelligent, space-faring aliens could really visit Earth, then, of course, they might satisfy the 1950s science fiction stereotype and land on the lawn of the White House wanting to meet the president.
“Another example is the discovery of technological equipment as relics from interstellar meteorites,” Leob wrote. “Such objects may contain unfamiliar components, such as the label ‘made on an exoplanet.'”
But even more compelling, Wright said, might be the detection of radio signals that can’t be generated by natural means. “Only technology can produce narrowband radio emissions,” Wright said. narrow range of frequencies Communicate data using bandwidth efficiently. He envisions “a lot of scenarios where we’re sure it’s technology or space stuff, but we’re pretty sure it’s not ours because it’s not local.” The Allen telescope array, several antennas at his SETI Institute in California, are designed to look for such signals.
But even the detection of an alien radio transmitter could open up a whole new level of analysis. Just because you receive a signal doesn’t mean it’s for you, that you can decipher it, or that you will respond if the sender speaks to you. “We say, ‘That star has radio communications.’ Sometimes you can see it, sometimes you can’t. Those are definitely technologies,” Wright said. “Yes, they have radio transmitters. And that’s all we know.”