Harvard scientists suggest 'Oumuamua is an alien device
It's an asteroid, it's a comet, it's actually a spacecraft?
- 'Oumuamua is an oddly shaped, puzzling celestial object because it doesn't act like anything naturally occurring.
- The issue? The unexpected way it accelerated near the Sun. Is this our first sign of extraterrestrials?
- It's pronounced: oh MOO-uh MOO-uh.
That odd-shaped visitor from beyond our solar system, 'Oumuamua (Hawaiian for "scout"), has been fascinating from the moment it arrived: It's a spaceship, it's a rock, it's a comet, it's not a comet. But is it a spaceship? That's where its behavior has some scientists at Harvard leaning; they suggest it may be a device of some kind powered by a lightsail, or a piece of one.
What's got experts so puzzled about 'Oumuamua is, as an about-to-be-published paper says: "'Oumuamua showed deviations from a Keplerian orbit at a high statistical significance." In English: It sped up as it approached the Sun. Comets can do this, but 'Oumuamua has been disqualified as an active comet, as it has no tail. Shmuel Bialy and Abraham Loeb, the authors of the paper, propose that the increase in speed could be due to "solar radiation pressure." The bottom line, they say, is that the discrepancy "is readily solved if 'Oumuamua does not follow a random trajectory but is rather a targeted probe." The paper discusses the math involved and finds that its "general results apply to any light probes designed for interstellar travel."
What we saw is what we get
That dot in the center is an actual image of 'Oumuamua.
'Oumuamua's gone from our view at this point, so any analysis of it or its movements is limited to the data collected during its period of observability. It was first spotted from the PAN-STARRS telescope on Maui (hence its Hawaiian name) on October 19, 2017, and by January 2018 it was gone. Any conclusions we draw have no way of being tested now.
At the time, 'Oumuamua was scanned for radio waves — a basic means of communicating which we assume/hope is the universe's lingua franca — and no radio waves were found, leading observers away from suspicions that its origin could be an alien civilization.
At first, 'Oumuamua was assumed to be an asteroid, but its subtle gain in speed as it drew near the Sun suggested a comet, and it still could be one, though of a kind with which we're unfamiliar. Comets accelerate near the Sun because, as NASA puts it, "Light and other radiation from the Sun push on the gas and dust in the coma, blowing the material away to form a tail that can be millions of kilometers long." The problem with 'Oumuamua is that it had no observable tail. In fact, we couldn't see it that well at all. As you can see in the photo above.
What did 'Oumuamua really look like?
We're all familiar with the shape ascribed to 'Oumuamua, as seen at the top of this article, but since the images really captured of 'Oumuamua showed it as a far-away dot, its presumed shape is a mathematically derived guess based on the way its brightness fluctuated, suggesting a tumbling, elongated object 10 times as long as it was wide. (Current calculations put 'Oumuamua at about 800 meters long.) The rest of its appearance was likewise deduced by its behavior. What many take to be its true appearance is just an artist's conception. So, we're used to feeling like we know what 'Oumuamua looked like, but we don't really know. If you find yourself thinking, "it sure doesn't look like an alien device," well, maybe.
Is 'Oumuamua a lightsail that remains from a larger craft?
The paper offers two theories, either of which would explain 'Oumuamua's odd acceleration. The first is that, "'Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment. Lightsails with similar dimensions have been designed and constructed by our own civilization, including the IKAROS project and the Starshot Initiative." Citizen-funded Planetary Society plans to launch one, simulated in the gif above, soon.
A lightsail is a device that uses in-space energy to propel craft via solar pressure. It uses the momentum from solar photons striking a large, thin, reflective sail. What's so interesting about craft powered by lightsail is that they can pick up the energy they need as they travel, rather than storing heavy fuel onboard.
Could 'Oumuamua be an actual probe deliberately sent here?
"A more exotic scenario is that 'Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization," suggests the paper. Apparently, if there were a lot of naturally occurring objects like 'Oumuamua, we'd be seeing lots of them. And we're not.
Two experts from SETI weigh in. And disagree.
Two scientists from SETI (Search for Extraterrestrial Intelligence), SETI director Andrew Siemion and senior astronomer Seth Shostak, have publicly commented on the conclusions drawn by Bialy and Loeb.
Siemion termed the paper "intriguing," telling The Globe that, "Observational anomalies like we see with 'Oumuamua, combined with careful reasoning, is exactly the method through which we make new discoveries in astrophysics — including, perhaps, truly incredible ones like intelligent life beyond the Earth." However, in an email to NBC, Shostak warned, "one should not blindly accept this clever hypothesis when there is also a mundane explanation for 'Oumuamua — namely that it's a comet or asteroid from afar."
LightSail: An experiment over 35 years in the making
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Here's the first evidence to challenge the "fastest sperm" narrative.
Experts argue the jaws of an ancient European ape reveal a key human ancestor.
- The jaw bones of an 8-million-year-old ape were discovered at Nikiti, Greece, in the '90s.
- Researchers speculate it could be a previously unknown species and one of humanity's earliest evolutionary ancestors.
- These fossils may change how we view the evolution of our species.
Homo sapiens have been on earth for 200,000 years — give or take a few ten-thousand-year stretches. Much of that time is shrouded in the fog of prehistory. What we do know has been pieced together by deciphering the fossil record through the principles of evolutionary theory. Yet new discoveries contain the potential to refashion that knowledge and lead scientists to new, previously unconsidered conclusions.
A set of 8-million-year-old teeth may have done just that. Researchers recently inspected the upper and lower jaw of an ancient European ape. Their conclusions suggest that humanity's forebearers may have arisen in Europe before migrating to Africa, potentially upending a scientific consensus that has stood since Darwin's day.
Rethinking humanity's origin story
The frontispiece of Thomas Huxley's Evidence as to Man's Place in Nature (1863) sketched by natural history artist Benjamin Waterhouse Hawkins. (Photo: Wikimedia Commons)
As reported in New Scientist, the 8- to 9-million-year-old hominin jaw bones were found at Nikiti, northern Greece, in the '90s. Scientists originally pegged the chompers as belonging to a member of Ouranopithecus, an genus of extinct Eurasian ape.
David Begun, an anthropologist at the University of Toronto, and his team recently reexamined the jaw bones. They argue that the original identification was incorrect. Based on the fossil's hominin-like canines and premolar roots, they identify that the ape belongs to a previously unknown proto-hominin.
The researchers hypothesize that these proto-hominins were the evolutionary ancestors of another European great ape Graecopithecus, which the same team tentatively identified as an early hominin in 2017. Graecopithecus lived in south-east Europe 7.2 million years ago. If the premise is correct, these hominins would have migrated to Africa 7 million years ago, after undergoing much of their evolutionary development in Europe.
Begun points out that south-east Europe was once occupied by the ancestors of animals like the giraffe and rhino, too. "It's widely agreed that this was the found fauna of most of what we see in Africa today," he told New Scientists. "If the antelopes and giraffes could get into Africa 7 million years ago, why not the apes?"
He recently outlined this idea at a conference of the American Association of Physical Anthropologists.
It's worth noting that Begun has made similar hypotheses before. Writing for the Journal of Human Evolution in 2002, Begun and Elmar Heizmann of the Natural history Museum of Stuttgart discussed a great ape fossil found in Germany that they argued could be the ancestor (broadly speaking) of all living great apes and humans.
"Found in Germany 20 years ago, this specimen is about 16.5 million years old, some 1.5 million years older than similar species from East Africa," Begun said in a statement then. "It suggests that the great ape and human lineage first appeared in Eurasia and not Africa."
Migrating out of Africa
In the Descent of Man, Charles Darwin proposed that hominins descended out of Africa. Considering the relatively few fossils available at the time, it is a testament to Darwin's astuteness that his hypothesis remains the leading theory.
Since Darwin's time, we have unearthed many more fossils and discovered new evidence in genetics. As such, our African-origin story has undergone many updates and revisions since 1871. Today, it has splintered into two theories: the "out of Africa" theory and the "multi-regional" theory.
The out of Africa theory suggests that the cradle of all humanity was Africa. Homo sapiens evolved exclusively and recently on that continent. At some point in prehistory, our ancestors migrated from Africa to Eurasia and replaced other subspecies of the genus Homo, such as Neanderthals. This is the dominant theory among scientists, and current evidence seems to support it best — though, say that in some circles and be prepared for a late-night debate that goes well past last call.
The multi-regional theory suggests that humans evolved in parallel across various regions. According to this model, the hominins Homo erectus left Africa to settle across Eurasia and (maybe) Australia. These disparate populations eventually evolved into modern humans thanks to a helping dollop of gene flow.
Of course, there are the broad strokes of very nuanced models, and we're leaving a lot of discussion out. There is, for example, a debate as to whether African Homo erectus fossils should be considered alongside Asian ones or should be labeled as a different subspecies, Homo ergaster.
Proponents of the out-of-Africa model aren't sure whether non-African humans descended from a single migration out of Africa or at least two major waves of migration followed by a lot of interbreeding.
Did we head east or south of Eden?
Not all anthropologists agree with Begun and his team's conclusions. As noted by New Scientist, it is possible that the Nikiti ape is not related to hominins at all. It may have evolved similar features independently, developing teeth to eat similar foods or chew in a similar manner as early hominins.
Ultimately, Nikiti ape alone doesn't offer enough evidence to upend the out of Africa model, which is supported by a more robust fossil record and DNA evidence. But additional evidence may be uncovered to lend further credence to Begun's hypothesis or lead us to yet unconsidered ideas about humanity's evolution.
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