Avi Loeb, a physicist from Harvard University in the US, is restored 50 small spherical iron fragments from the bottom of the Pacific Ocean that he claims are material from an interstellar alien spacecraft.
Loeb links his finding to the passage of a fireball in January 2014. The meteor was observed by United States Department of Defense sensors that track all objects entering Earth’s atmosphere.
It was recorded as traveling faster than most meteors and eventually erupted over the South Pacific near Papua New Guinea.
Data on the object is held by NASA’s Center for Near Earth Object Studies (CNEOS). The official name of the meteor is CNEOS 20140108 and is also known as IM1 (for interstellar meteor).
A very large scientific leap has been made from observing a fireball to claiming it to be an alien starship. What is the evidence on which Loeb bases the claim? And how likely is it to be true?
‘Oumuamua, an interstellar comet
We have already had at least one visitor from interstellar space: the comet ‘Oumuamua. The appearance of 1I/2017U1, the official name for ‘Oumuamua, was certainly an unusual event.
The object was observed in 2017 as it left the solar system. Are procedure differs from the near circular orbits of the planets and elliptical orbits of comets.
The comet’s path was traced and scientists found it came from far beyond the outer edges of the solar system.
Scientists were excited but also intrigued – although the shape wasn’t captured on camera, the way the light bounced off it as it spun around suggested it had an odd shape, like a cigar when viewed from the side or a plate when viewed from the side. view from above.
In a thoughtful article written in 2018, Loeb speculated that ‘Oumuamua may be artificial, rather than natural in origin – the product of an alien civilization. He suggested that we should keep looking for interstellar debris in the solar system.
In chasing such debris, Loeb’s team interrogated the CNEOS database, looking for objects with unusual orbital features. Then they found CNEOS 20140108 and based on its high speed suggested that it is a interstellar meteor – giving it the more manageable name of IM1.
Loeb modeled the fireball’s path and identified a specific area of the South Pacific where he believed debris from IM1 would be deposited. After a dredging operation in the area with a powerful magnet, he now claims to have found it material from IM1.
But what are the chances that he actually found interstellar debris, let alone a starship?
Cosmic balls?
The metal spheres that have been recovered are each about half a millimeter in diameter. It is not impossible that they are of extraterrestrial origin: several previous expeditions have recovered spheres from space from the seabed.
The first expedition to find such monsters was HMS Challenger in 1872-76. Material dredged from the ocean floor contained many metallic droplets, described quite accurately at the time as “cosmic spheres”.
Droplets from space are spherical because they solidify from molten material ripped from the surface of meteorites as they travel through the atmosphere.
Subsequent expeditions in the 20th century have also found cosmic spheres at the bottom of the ocean, but identifying them has become more difficult. This is because in the 150 years since the Challenger expedition, the amount of pollution on earth has increased.
In 1872, the industrial revolution in Europe was still in its infancy and practically non-existent in the southern hemisphere. Hence pollution such as “fly ash” (waste from burning coal) and particulate matter from vehicles was minimal. Many of these pollutants also have a spherical appearance and metallic composition.
Today, products of industrial processes and vehicles can be found everywhere. So without an actual analysis of the composition of the spherules and a comparison with analyzes of meteorites (and common terrestrial pollutants), it is not possible to identify them as extraterrestrial.
Interstellar?
But Loeb doesn’t just think the material comes from space, he thinks it comes from interstellar space “this could be the first time humans get their hands on interstellar material”.
This is simply not true. We have an abundance of interstellar material on Earth. Some of it is almost certainly on the ocean floor, but not in the form collected by Loeb.
The interstellar material I am talking about exists in different varieties. It is known to astronomers that the interstellar medium – the space between the stars – is not empty, but contains various molecules, many of which are organic (consisting of chains or rings of carbon).
Some of these molecules became mixed with the part of space where the solar system began to form.
Stars themselves have also contributed material to the interstellar medium as they evolved or exploded as supernovae. Some of this material comes in the form of tiny diamonds or sapphires — rare mementos of stars that lived and died before the sun was born.
These grains became part of the cloud of dust that collapsed to form the solar system and were eventually carried to Earth in meteorites.
Alien spacecraft?
Loeb’s evidence for an extraterrestrial source for the material — let alone an interstellar origin — is rather shaky.
He found metal balls. For me (and many others) to accept that these spheres are extraterrestrial, I need solid analytical evidence. What is their composition? What is their age? Can we rule out terrestrial pollutants? Can we exclude extraterrestrial debris from the solar system?
The first question, about the composition, has been answered: Analysis of the spheres shows that they are mainly iron with a few trace metals.
We know that meteors from our solar system contain iron and nickel, a reflection of the relative amounts of these metals in the sun. But the spheres apparently contain “negligible” amounts of nickel — indicating they almost certainly didn’t come from meteors in the solar system.
However, this does not prove they are interstellar – it just makes it more likely that they are terrestrial pollutants.
The most convincing evidence would be to measure an age for the spheres larger than that of the sun – which would identify them as interstellar.
And that would be amazing, but it wouldn’t necessarily identify them as having an artificial, rather than natural, origin. I’m not sure what evidence would be convincing enough for this – perhaps the signature of the alien engineer who built the spacecraft?
Monica Gradyprofessor of planetary and space sciences, The Open University
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