Unveiling the Mystery of ‘Oumuamua: Astronomers Discover Dark Comets in Our Solar System
How do you distinguish between a spaceship and a space rock? This question has puzzled astronomers for years. When the first recorded interstellar object, named ‘Oumuamua, was spotted passing through our solar system in 2017, astronomers were almost fooled. Initially, they believed that any object moving under its own speed, with no visible means of propulsion, must be artificial technology. However, ‘Oumuamua defied all expectations and acted in ways that contradicted our understanding of interstellar space rocks.
During its brief visit to our solar system, ‘Oumuamua was observed by telescopes across the world. These observations revealed that the object came from outside our solar system and had an extremely elongated and tumbling shape. What was most surprising was that ‘Oumuamua displayed no comet-like tail but still moved under its own propulsion. Comets typically exhibit beautiful tails caused by dust and ice blown off their surfaces, but ‘Oumuamua was different.
This mysterious flight through our solar system sparked speculation about its artificial origins. Some astronomers even referred to it as Rama. However, further analysis revealed a different explanation – ‘Oumuamua was an entirely new kind of object known as a “dark comet.” Since the discovery of ‘Oumuamua, astronomers have identified a population of seven dark comets hiding among our solar system’s asteroids. These dark comets move like comets but lack the characteristic dust tail.
The existence of interstellar travelers has long been predicted by science fiction writers, but identifying them in reality is far from easy. The challenge of understanding ‘Oumuamua highlighted the need for advanced telescopes like the James Webb Space Telescope (JWST) and the forthcoming Rubin Observatory Legacy Survey of Space and Time (LSST) in Chile’s Atacama Desert. These telescopes will provide the tools necessary to make sense of future interstellar visitors and expand our knowledge of the cosmos.
If the JWST had been available when ‘Oumuamua was discovered, astronomers could have captured more detailed images of the object and gathered information about its appearance in different wavelengths of light. This would have allowed for a better understanding of its propulsion mechanism. By detecting molecules like water or carbon dioxide that only show up at specific wavelengths and don’t reflect sunlight, astronomers could have identified ‘Oumuamua as a dark comet-like object. Fortunately, there is already an approved JWST program in place to monitor future interstellar objects.
In addition to the JWST, the LSST, set to come online in the near future, will play a crucial role in detecting interstellar objects and identifying dark comets within our solar system. Located in the Atacama Desert, an ideal location for observing the sky, the LSST will scan the entire Southern Hemisphere sky almost every night. Its advanced capabilities will enable the detection of fainter objects, including dimmer interstellar objects like ‘Oumuamua. The LSST will also contribute to the discovery of smaller asteroids and their classification as dark comets.
With the LSST’s anticipated capabilities, it is possible that we may start detecting interstellar objects on a monthly or even weekly basis. Some of these objects may resemble ‘Oumuamua, while others may exhibit beautiful tails like the second interstellar comet, 2I/Borisov. It is even conceivable that there are numerous smaller interstellar visitors continuously passing through our solar system, previously invisible to us. If this turns out to be the case, the LSST might identify an interstellar target close enough for a dedicated space mission.
The era of close encounters with interstellar visitors is no longer confined to science fiction. With the JWST and LSST, astronomers have the necessary tools to differentiate between intelligent visitors and interstellar dark comets. It is crucial not to be deceived by appearances. By leveraging these advanced telescopes, we can unravel the mysteries of our universe and gain a deeper understanding of the cosmos.
Darryl Seligman, a research associate in the Department of Astronomy at Cornell University, focuses his research on theoretical and computational planetary science and astrophysics. His expertise contributes to the ongoing exploration of our solar system and beyond.
