In 2017, astronomers around the world were excited about the first interstellar object to pass through the Solar System - well, at least the first one that was noticed. In cigar form, Oumuamua, as it was called, traveled at 44 km / s, but its origin was a mystery. While Harvard researchers said it could even be an alien probe, another group of scientists dismissed that hypothesis. Now, a new theory points out that it would be the rest of a large planet.
The explanation came from astronomers at the University of California, who through computer simulations deduced that Oumuamua would have been a planet pulverized by a star. Thus, his remains began to roam the space. In other words, the object would be just a part of a puzzle of what is left of that planet. If other pieces followed the same path, it is possible that the Solar System will be visited again soon.
The search for interstellar objects began more than a decade ago, but the expectation was to find a comet from the far reaches of the Universe. That is why the passage of a “cigar” has become quite unusual and curious. After him, Borisov became the second interstellar object to pass through - this, in fact, a traditional comet.
“We showed that objects similar to Oumuamua can be produced with extensive fragmentation after encounters between their parent bodies and their host stars and then ejected into interstellar space,” explains Douglas Lin, one of the authors of the research, published in Nature Astronomy.
Discovered by an observatory in Hawaii, the object was named Oumuamua, which, in the local language, means something like “messenger from afar arriving first”. Its speed of removal from the Sun and its shape soon puzzled researchers, but the quest to determine its origin and what it was really was just beginning.
The new theory reaffirms something thought at the end of 2017: the object would be the result of a phenomenon known as tidal disturbance. This happens when gravity is able to distort a body - something that the Moon does by stretching the Earth’s circumference, creating high and low tides around the planet. A black hole would also be able to make this movement elastic, so Oumuamua could have undergone this process and generated its elongated shape. With that hypothesis in hand, the new study used computational models to see if this was physically possible - and it was.
This analysis also explains the speed of the object: when it approached the Sun, the heat caused the residual ices from the Oumuamua’s crust to be released, making it accelerate when it reached our neighborhood. Currently, it must be passing close to Uranus, which is a long way for today’s ground-based telescopes to get more information.
