A VISITOR FROM BEYOND
ASTRONOMERS FROM THE UNIVERSITY OF HAWAII DISCOVER THE FIRST ASTEROID FROM OUTSIDE THE SOLAR SYSTEM
As Robert Weryk scanned through another batch of vivid images revealing asteroids, comets and other high-velocity space rocks shooting close enough past the Earth to cause alarm, one object caught his attention. It was fast moving, oddly shaped and looked like it came from an inexplicably far away place. While it had initially seemed to be a mistake, Weryk had in fact made a historic discovery. He just didn’t know it yet.
At first, the data just didn’t seem right. In three years as a postdoctoral fellow for the University of Hawaii’s Institute of Astronomy, Weryk had come across countless other fast-moving Near Earth Objects using data gathered by the facility’s Pan-STARSS 1 telescope. Despite differences in size, shape or speed, all of these cosmic bodies were bound by the orbit of the Sun and linked in their shared residency of the Solar System.
Whatever Weryk had found, it had come from far beyond our solar system.
“At first, I thought this was another asteroid,” Weryk said. “But when I combined the data, it didn’t make sense. Something was up.”
Only after confirming the trajectory of the strange rock with data gathered at the European South Observatory in Tenerife in the Canary Island did Weryk realize that this mysterious object had not originated from within the Solar System at all but from farther away.
The object Weryk found was dark red in color, peculiarly elongated and about 400 meters in length, about the size of an aircraft carrier. It had been barrelling through the cosmos at more than 50,000 miles per hour for an unknown amount of time. Originating from billions of miles away in the direction of the constellation Lyra, it had come close enough to the Sun to be pulled in by its immense gravity and, in a game of cosmic pinball, hooked around the center of our Solar System and launched back into space, directly into the crosshairs of the Pan STARRS telescope on the night Weryk happened to be working.
Initially called “A/2017 U1,” it was later given the Hawaiian name “‘Oumuamua,” meaning “foremost scout,” and, unlike all others that had come before, it was the first interstellar object to be monitored in human history.
For Weryk, another day at the office had ended up yielding one of the most significant astronomical discoveries in decades.
“The scientific community was anticipating the discovery of an interstellar object,” says Paul Chodas, manager of NASA’s Jet Propulsion Lab. “We didn’t know if we would ever find one.”
“We really didn’t know what it was” at first, Weryk said. Its trajectory, speed and what astronomers initially took to be it’s smaller size lead Weryk and others to believe it was a standard comet.
After realizing it lacked traits essential to how comets are categorized -- such as the bright coma and trailing gas tail that accompanies bodies such as the more well known Halley’s Comet -- that assessment was thrown into doubt.
After intense studying and clarification, ‘Oumuamua was finally labeled an asteroid, albeit an odd one. It traveled through space with the tumbling motion of a flipped coin, and whereas most asteroids or comets have a typically round and more planet-like shape, ‘Oumuamua appeared to be incredibly elongated and at least ten times longer than it was wide.
“It’s good to keep it this way because the goal of the school is to help the children of ancestry. … We live in society where people of color have a hard time to get an education. If they feel the person is well off, why not help those who are struggling?”
Structural eccentricities aside, the discovery of ‘Oumuamua has since greatly excited the scientific community for a number of reasons, among them the fact that it exists in the first place. Before Weryk discovered the interstellar visitor, astronomers weren’t even sure asteroids, comets or any other heavenly bodies existed outside the Solar System in the first place.
“The theories of the foundations of planets have it that they will scatter small bodies into interstellar space,” Chodas said. “Presumably the same way our solar system ejected a great deal during its formation.”
According to these theories, the Solar System began as little more than a dense space of gas and particles. Over millions of years, these infinitesimal floating specks of dust and matter clumped together, growing larger and larger until they collided with other, similar bodies. The impact of these immense collisions eventually formed the planets as we know them, and sent all manner of debris shooting into space at high velocities along the way.
“The theorists can propose that they think something exists,” Weryk said. “And then it’s really up to the observers to either confirm or deny this.”
These small bodies include what we now know and recognize as comets, meteors and asteroids, like the unusual visitor Weryk cataloged. In discovering ‘Oumuamua, Weryk was able to finally give credence to long-attested speculation, turning theory into reality.
“That was the theory,” Chodas said. “This is the evidence. This one is from beyond.”
Now that there exists tangible proof that planets on opposite ends of the galaxy can form the same way that those in our Solar System did, then perhaps, astronomers hope, they share other
similarities as well.
“The hope,” Chodas said, “is to find out whether it’s made of the same composition that we find in our solar system and whether there are any differences relative to what we would expect from material in our own solar system.”
The discovery, which Weryk claims was lucky to be made in the first place, has given astronomers renewed hope for future findings.
“A component of it is pure chance, a big part of it is luck,” Weryk said. “We didn’t necessarily look in the right place before. Now that we know these objects exist, we can try to tune our strategy to find them more easily.”
Richard Wainscoat, a fellow astronomer at the University of Hawaii’s Institute of Astronomy, said the discovery of ‘Oumuamua motivates astronomers to continue their search for interstellar objects and gives hope for future discoveries of a similar vein to be made.
“When something is moving quickly across the sky it’s easy to lose it, it sort of highlights the need for more telescopes,” Wainscoat says.
A similar telescope, Pan-STARRS 2, is in the process of being built at the same Haleakala site, though its completion was fraught by ongoing budget concerns. The controversial Thirty Meter Telescope that was to be built atop Mauna Kea, a site that many Hawaiians deem sacred land, would have been able to gather similar data to what Pan-STARRS 1 can gather.
While the astronomical future of Hawaii remains in limbo, however, Wainscoat hopes that such groundbreaking discovery will, in the meantime, drum up a renewed public interest in astronomy and science in general.
“Hopefully it does excite the public,” Wainscoat says. “Get people a little more interested in our place in the universe.”
With full time operations beginning in 2010, the Pan-STARRS 1 Telescope takes continuous high quality photographs of fixed points in the sky. The telescope boasts a ridiculous picture quality of 1.4 billion pixels per image and is, technically, the largest digital camera ever build.
While the telescope is capable at peering off into far off galaxies and snapping shots of distant supernovae a billion miles away, scientists like Weryk focus their search in proximities much closer than that. Instead, the telescope is mainly used to monitor the thousands of Near Earth Objects that shoot through the skies at any given moment.
MEET THE PAN-STARRS 1 TELESCOPE
A CRASH COURSE IN NEAR EARTH OBJECTS
Since 1898 over 17,000 NEOs have been observed and noted by scientists across the globe. Some are no bigger than a baseball and pass over without much fuss, while others, like the 300 meter-wide asteroid 4581 Asclepius that came within roughly twice the distance of the Moon from the Earth in 1989, would have registered the energy of a 600-megaton bomb had it collided with the planet.
Bound by the immense gravitational pull of the sun, Near Earth Objects share a relative familiarity in that they all originate from within our solar system. Large or small, all NEOs are linked by a common thread, or rather, a common gravity.
They were, at least, until ‘Oumuamua came along.
According to its angle of spaceflight, speed and trajectory, astronomers have come to the conclusion that ‘Oumuamua point of origin lies somewhere within the constellation Lyra – situated, at some points, over 1,000 light years away from the Earth.
Lyra, or “lyre” in latin, has was among the 48 constellations first monitored by the 2nd century Roman Astronomer Ptolemy and is listed as one of the 88 constellations recognized by the International Astronomical Union. It contains one of the brightest stars in the night sky, Vega, and can be seen from both the Northern and Southern Hemisphere’s. Scientists theorize that a number of planets orbiting one of Lyra’s stars, Kepler-62, are well within the habitable zone; meaning they possess features that could possibly allow them to support life in the same way Earth has.
While there’s no way to pinpoint exactly where ‘Oumuamua originated, for now astronomers can look to the Lyra Constellation as the asteroid’s home.
A VISITOR FROM LYRA
Photo courtesyof: ESO/ M. Kornmesser
“This discovery motivates everybody to try a little harder to find things like this and gives us a few clues why maybe we saw them in the past and never realized what it was,” Wainscoat said.
However, as a result of only being directly monitored by a single telescope for a brief window of time, Wainscoat says that ‘Oumuamua is now “no longer easy to study” - a drawback that in itself strengthens the case for a more comprehensive network of high-powered telescopes to be built.
The Pan-STARRS 1 telescope
With ‘Oumuamua now come and gone, Wainscoat says the scientific community must keep a watchful, if optimistic eye to the skies.
“This one is never going to come back,” says Wainscoat. “It doesn’t have any real relation to the sun, it’s just a visitor. More will be going to be discovered – just when you get lucky.”
With any such luck, astronomers eagerly anticipate that ‘Oumuamua will be the first of many interstellar objects to make its way into the focused gaze of scientists and astronomers the world over. As similar cosmic travellers make the long journey across the universe and into our solar system, perhaps scientists will come to more profound and comprehensive understandings about the universe and the common threads that link what occupies its vast expanses.
Until then, scientists like Robert Weryk keep an eye to the sky, waiting and watching for another visitor from beyond.