#^Oumuamua Return: A Story Of The Cigar-Shaped AsteroidSometimes, space brings us such mysteries that scientists from all over the world have been racking their brains over them for years. One of them is the story of an interstellar visitor named Oumuamua. In 2017, this unusual object flew through our solar system, leaving us with many unanswered questions. In this article, we will tell you the details of this mysterious space wanderer and try to answer the main question that worries many: Will Oumuamua return?
What Is Oumuamua, And Why Is NASA Terrified Of It?
This intense combined image shows the interstellar object ‘Oumuamua in the centre. It is surrounded by faint star trails that are smeared as the telescopes tracked the moving comet. Credit: ESO/K. Meech et al.
Let’s move back to October 19, 2017, to Hawaii. The Pan-STARRS 1 telescope discovers an unidentified object that probably came to us… from beyond the Solar System. The discovery causes an unprecedented excitement in scientific and pseudo-scientific circles. And why not! After all, this is the first interstellar object registered in the history of space observations. The unexpected visitor is given a name to match: Oumuamua, which in Hawaiian means “first scout from afar.” And then the continuous mysteries begin.
Getting Oumuamua real image turned out to be almost impossible. The asteroid was small (about 400 m long and about 50 m wide), and at the time of discovery it had already passed its closest point to the Sun (perihelion) and was quickly moving away. Measurements made by ground-based observatories were more or less successful, but Oumuamua Hubble images turned to be unsuitable, so the Hubble official site had to limit itself to an artist’s illustration.
Oumuamua Artist’s impression. Credit: hubblesite
At first, the mysterious guest was classified as a comet, but later, it became clear that something was wrong. The “First Scout” showed no signs of a coma (a cloud of gas and dust) typical of comets. A reasonable question arose: Is Oumuamua an asteroid? But even here, everything turned out to be complicated.
Instead of the usual “boulder” (which is exactly what most asteroids in the Solar System look like, as you could read about in our articles
What are Asteroids and
Asteroid vs Meteor), our object turned out to be elongated, like a cigar, and slightly flattened. In addition, the cigar-shaped asteroid was moving with abnormal acceleration and along a hyperbolic trajectory, which indicated that it had never been gravitationally bound to our Sun and was simply flying by.
This data raised the boldest hypotheses about the origin of the “First Scout”. In particular, Harvard University professor Abraham “Avi” Loeb
suggested that the mysterious interstellar visitor could be an alien probe. Mass media immediately picked up this version and seriously distorted it. This is where the rumours about “NASA’s scare” came from. NASA, like other space agencies and scientists, were more intrigued than scared. After all, the object did not pose a danger of collision with Earth or other planets of the Solar System, but the very fact of its arrival was a truly unique event.
Where Did Oumuamua Come From? Scientific Hypotheses On The Origin
Origin’s story for ‘Oumuamua, using images from NASA and ESO/L. Calçada. Credit:planetplanet.net
No matter how hard scientists tried, they could not define the exact place of origin of the “First Scout”. The trajectory analysis showed that it arrived from the direction where the star Vega (the Lyra constellation) is located. But, given the average speed of the object (44 km/s) and the time of its travel (probably hundreds of millions or even billions of years), Vega itself was in a completely different place at the time of the launch of the Oumuamua object. Most likely, our wanderer wandered around the Milky Way for a very long time before getting into the Solar System. But what made it leave its home?
1. Gravitational Slingshot Or “Grand Tack” Hypothesis
One of the most likely versions suggests that the first scout was thrown into interstellar space as a result of close gravitational interaction with a massive gas giant planet in its forming star system, similar as it was with Jupiter that threw out small bodies (planetesimals) from our Solar System.
2. Exoplanet Fragment
Another intriguing hypothesis suggests that the “First Scout” is a fragment of an exoplanet similar to Pluto, composed primarily of nitrogen ice. A collision in its home system could have ejected the fragment, and sublimation of nitrogen as it approached our Sun could explain its strange acceleration.
3. Comet Remnant
Some researchers have suggested that Oumuamua could be the remnant of a comet that was tidally disrupted or otherwise destroyed during its journey.
The real reason for Oumuamua’s journey is still a mystery, and perhaps future missions to interstellar objects will be able to shed light on it.
Where Is Oumuamua Now In 2025?
This NASA animation depicts the trajectory of ‘Oumuamua, as it moves through the inner solar system.
Credit: NASA/JPL-Caltech
It is impossible to answer exactly where is Oumuamua right now, since its location is constantly changing. It is known that about 5 years ago it left the Kuiper belt, and now it is moving far beyond our Solar System (at a distance of more than 100 AU from Earth) towards the constellation of Pegasus. However, due to the huge distance and great dimness, even such a powerful telescope as the James Webb is not able to see Oumuamua. It is like trying to look for a needle in a haystack.
For illustrative purposes, we have compiled a table of all the Oumuamua asteroid journey stages through our Solar System:
Is The Asteroid Oumuamua Coming Back? Farewell, Mysterious Wanderer!
And now, finally, we come to the burning question: will Oumuamua return? Unfortunately, the fans of sensations will have to be disappointed, no matter how hard they tried to pull the non-existent words of Elon Musk that “Oumuamua Has Suddenly Returned, and It’s Not a MISTAKE!” This is nothing more than a clickbait headline.
The object is moving along an open, hyperbolic trajectory, inexorably moving away from the Solar System into interstellar space. Approximately by 2038, it will reach the heliopause (the boundary of the heliosphere) and finally leave the gravitational influence of the Sun. In other words, scientists should not expect an Oumuamua return date. The first scout will never return.
Oumuamua Impact: Lessons From An Interstellar Guest
Although our unexpected guest was not planning to collide with the Earth, its visit (let’s call it the Oumuamua impact on science) is extremely important. It showed that such interstellar objects are not unique (
Borisov comet, which flew 2 years after Oumuamua, is a clear confirmation of this), and that we need to be ready for their appearance. After all, who knows what they could bring?
Imagine that an interstellar asteroid did crash into the Earth… We wrote about the consequences of such a collision in detail in our article
Will an Asteroid Hit Earth. Taking into account the enormous speed and size of the object, the explosion would have been thousands of megatons of TNT, which would have formed a giant crater, dust, tsunamis, and earthquakes… In general, a real Armageddon with all that it entails.
Was The Cigar-Shaped Asteroid An Occasional Visitor Or A Warning?
So, now that the Oumuamua return question is solved, we can only wait for the next guests and hope that they will not have hostile intentions. In the meantime, all we can do while we wait is study asteroids and other similar objects not only for
asteroid mining but also for protection against them. Who knows, maybe this was the “First Scout” mission.
References And Additional Information:
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Oumuamua Return: A Story Of The Cigar-Shaped Asteroid appeared first on
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