‘Oumuamua, an interstellar Messenger from another Solar System
On October 19th, the Pan-STARRS 1 telescope in Hawaii spotted something strange zooming through our solar system. It turned out to be a visitor from beyond our system, and it is unlike anything astronomers have seen before.
According to a study published in the journal Nature, it is the first observed object that has come from another solar system entirely. The astronomers first thought the rapidly moving faint light was a comet or an asteroid that had originated in our own solar system. Now, based on its orbit, the astronomers realize that the object came from interstellar space.
Acting fast, multiple telescopes focused on the object for three nights to determine what it was before it moved out of sight, moving at 85,700 miles per hour.
A Messenger from Long Ago
The lead study author Karen Meech, of the University of Hawaii’s Institute of Astronomy stated that, “What we found was a rapidly rotating object, at least the size of a football field, that changed in brightness quite dramatically.” This long rocky cigar-shaped object has a burnt dark-reddish hue due to millions of years of radiation from cosmic rays. This hue is similar to that of objects found in the Kuiper Belt, in the outer part of our solar system, but its orbit and shape place it in the category of interstellar origin. It most likely has a high metal content and spins on its own axis every 7.3 hours.
The shape however, is baffling to astronomers. It is 10 times as long as it is wide. This has never been seen before. The complex shape means the object varies incredibly in brightness. The most elongated objects astronomers had previously seen were only three times longer than their width.
What could this be?
The object is the first to be named an interstellar asteroid, officially designated A/2017 UI by the International Astronomical Union, which created the category after it was discovered. Its official short name is ‘Oumuamua. Simply translating to the Hawaiian name for a messenger that reaches out from the distant past.
The associate administrator for NASA’s Science Mission Directorate, Thomas Zurbuchen states, “For decades we’ve theorized that such interstellar objects are out there, and now for the first time we have direct evidence they exist. This history-making discovery is opening a new window to study formation of solar systems beyond our own.”
What is its Origin?
Astronomers know that when our solar system was forming, it effectively spit out comets and asteroids because of the orbits of the largest planets. So it would make sense that other planetary systems are sending the same remnants our way. That means this visitor could carry the secrets to how other solar systems were formed. It is possible that there are between one and 10 of these types of “visitors” per year in our solar system, but go missed because of how fast they move.
The suggested origin of ‘Oumuamua came from the direction of Vega, a bright star in the Lyra constellation. However, even at 85,700 miles per hour, it took so long to reach our solar system that Vega wasn’t in the same position 300,000 years ago, meaning its origin can only be predicted and most likely never confirmed.
Astronomers believe that the object could have been traveling through our home galaxy, the Milky Way, for hundreds of millions of years, without being attached to any star system, before reaching us. This means that no gravitational pull was used to speed it up, this allowed us to see it today.
That’s not to say that this object is slow by any means. If it were to crash into Earth, it would have a much greater impact and create more energy than an object from our own solar system.
NASA Planetary Defense Officer Lindley Johnson states that, “We are fortunate that our sky survey telescope was looking in the right place at the right time to capture this historic moment. This serendipitous discovery is bonus science enabled by NASA’s efforts to find, track and characterize near-Earth objects that could potentially pose a threat to our planet.”
Ground- and space-based telescopes, like Hubble and Spitzer, are continuing to track ‘Oumuamua for as long as they can. It is 124 million miles from Earth, which is the distance between Mars and Jupiter. Fortunately, its trajectory has taken the object past Mars’ orbit, and it will pass Jupiter in May. In January 2019 it will travel beyond Saturn’s orbit and leave our solar system toward the Pegasus constellation.
Having been able to detect and observe ‘Oumuamua, astronomers are hopeful they can prepare to observe other such objects in the future. One of the study authors from the European Southern Observatory, Olivier Hainaut states, “We are continuing to observe this unique object and we hope to more accurately pin down where it came from and where it is going next on its tour of the galaxy. And now that we have found the first interstellar rock, we are getting ready for the next ones!”
Could Alien Life be Involved?
In a CBS News interview reported by Tony Dokoupil, Harvard scientists theorize that this visitor may have been a probe sent by an alien civilization. The very name given to this object ‘Oumuamua, “messenger that reaches out from the distant past,” even suggests this. They say that there are things about its behavior that can’t quite be explained. The Harvard scientists admit that their theory is a little out there, but they believe that it wouldn’t be the most fictional discovery.
The chair of the Harvard University astronomy department, Avi Loeb states that, “It looks very different from objects that we have found in the solar system.” She said that ‘Oumuamua does not behave like an ordinary asteroid or give off gas like a comet. “There seemed to be an extra force that is pushing it, and it’s not clear what this push is from,” she added.
Loeb and her colleagues offer what they call a “a more exotic scenario where Oumuamua may be a fully operational probe sent intentionally to earth’s vicinity by an alien civilization.” According to their calculations, ‘Oumuamua is less than a millimeter thin, but very wide like a sail, harnessing solar radiation to propel itself. This is similar to the spaceship used by Count Dooku in the “Star Wars” films.
However, Jackie Faherty, an astrophysicist at the American Museum of Natural History wants to make it clear that they, “want everybody to take that with a gigantic grain of salt.” The ‘Oumuamua does not emit any signals suggesting it was a space craft.
As hard as it is to fathom the existence of aliens, it’s apparently even harder to fathom the idea that we’re alone.
– Jackie Faherty
Science Fiction Once Again Comes to Reality
This theory is parallel with the science fiction theory created by Arthur C. Clarke about his Monolith in the book 2001: A Space Odyssey. The Monolith was a probe sent millions of years ago to different planets in order to study life across the universe. If this theory proves to be true, the human race is in for quite an exciting exploration, chasing after the source of ‘Oumuamua.