Scientists rushed to observe the object before it disappeared, at a speed of 196,000 miles per hour, and their observations raised more questions than answers about the “ eccentric ball, ” as scientists called it.
Now the latest research suggests it is a fragment of a Pluto-like planet from another solar system.
Upon discovery, the object was named ‘Oumuamua, Hawaiian for’ a messenger reaching from the distant past ‘. Initially, astronomers expected it to be a comet.
But the dry, rocky reddish, elongated cigar-shaped object, as thick as a building three stories and half the length of a city block, did not have a comet tail, and its tumbling motion could not be explained. And debate has arisen as to whether it is an interstellar asteroid or a comet.
And, of course, it was speculated that ‘Oumuamua was some kind of alien probe.
“Oumuamua was in many ways like a comet, but in several ways it was curious enough that the mystery surrounded its nature, and speculation about what it was,” Desch, who is also a professor at ASU, said in a statement.
Clues to the missile impact
Oumuamua differed from comets in several ways, including the fact that it had a slower speed when it entered our solar system. If it had traveled through interstellar space as a comet for over a billion years, it would have had a faster speed.
Its shape was flattened like a pancake, unlike comets that are like cosmic snowballs. The object also received a significant boost, known as the “rocket effect,” greater than what comets experience when their ice evaporates when they meet the sun.
The researchers wondered if ‘Oumuamua was made of ice with different compositions, which allowed them to calculate how quickly the ice would turn to gas if the object was zipped by the sun. This also allowed Desch and Jackson to determine the mass, shape and rocket impact and assess how reflective the ice was.
“We realized that a patch of ice would be much more reflective than people thought, which meant it could be smaller. The same rocket impact would then give ‘Oumuamua a bigger push, bigger than comets usually experience,” said Desch.
In our solar system, Pluto and Saturn’s moon Titan are largely covered with nitrogen ice. If the object is mostly nitrogen ice, it is possible that a solid portion of it was expelled from a Pluto-like planet after entering another planetary system.
The same thing happened in our own solar system, including Pluto and objects in the icy Kuiper Belt. This distant belt of objects at the edge of our solar system was once more massive than it is today.
When Neptune migrated to the outer solar system billions of years ago, it disrupted the orbits of these objects left over from the solar system’s formation. Thousands of objects similar to Pluto covered in nitrogen ice collided.
If that could happen in our own solar system, it is very likely that the same event could happen in another solar system, meaning that ‘Oumuamua could be the first monster of an exoplanet born around another star and headed to Earth brought, ” the authors wrote in the study.
“It was probably knocked off the surface by an impact about half a billion years ago and thrown out of its mother system,” Jackson, also a research scientist and a researcher at ASU, said in a statement.
Made from frozen nitrogen also explains the unusual shape of ‘Oumuamua. As the outer layers of nitrogen ice evaporated, the body’s shape would have gradually become more flattened, much like a bar of soap does when the outer layers are rubbed off. . “
The researchers estimate that ‘Oumuamua’s encounter with our sun caused it to lose 95% of its mass.
Alien speculation
Theories that ‘Oumuamua is an alien object or piece of technology have been circulating since the object appeared, and it is the basis for the new book’ Extraterrestrial: The First Sign of Intelligent Life Beyond Earth ‘by Avi Loeb, a professor of science at Harvard University.
There is no evidence to prove that ‘Oumuamua is alien technology, the researchers of this study said, although it is normal for the first object observed from outside our solar system to be reminiscent of aliens.
“But it’s important in science not to jump to conclusions,” said Desch. “It took two or three years to come up with a natural explanation – a chunk of nitrogen ice – that matches everything we know about ‘Oumuamua. natural explanations. “
However, Oumuamua has been a unique way for scientists to study an object outside our solar system. Understanding more about ‘Oumuamua, which disappeared from view in December 2017, may shed more light on the formation and composition of other planetary systems.
“Until now, we had no way of knowing if other solar systems have Pluto-like planets, but now we’ve seen a piece of one go beyond Earth,” Desch said.
Future telescopes, such as the Vera Rubin Observatory in Chile, will regularly view the entire sky visible from the Southern Hemisphere, allowing us to see more interstellar objects entering our solar system. The observatory will be operational from 2022.
“It is hoped that in a decade or so we can get statistics on what kinds of objects pass through the solar system and whether chunks of nitrogen ice are rare or as common as we have calculated,” Jackson said. “Either way, we should be able to learn a lot about other solar systems and whether they have gone through the same kind of collision histories as ours.”