As our first interstellar visitor, Oumuamua (“scout”, in Hawaiian) arrived in the solar system, raising a huge wave of speculation about its origin. Now, the theory at the time says that he is a gigantic “bunny” of cosmic dust (like those dust balls that roll over furniture), according to a study recently published in The Astrophysical Journal Letters.
According to astronomer Jane Luu, from the University of Oslo and the research leader, the origin of this strange interstellar space rock would be a “long period” comet (so called because it takes a long time to circle the stars and move away from them), traveling outside our solar system.
When it was ejected, a large chunk of rock added dust and gas particles that escaped away from the comet’s core. As the Oumuamua grew, the gas pushed the rock into space due to solar radiation.
From ETs to solid hydrogen
Oumuamua was first sighted in October 2017, and soon all the telescopes on the planet turned to the strange elongated rock, which traveled through space at a bizarrely unusual speed: 92,000 km / h.
If one of the first theories said that it should be formed of solid hydrogen (as it was approaching the Sun it turned into gas – boosting of the rock cigar), soon others appeared, which stated that Oumuamua had the shape of a disc (it was “a jump” for him to be an alien probe)) or even the remains of a large planet.
What is known today about him?
It came from outside the solar system and, according to NASA astronomers, the object has already entered at high speed, not suffering the gravity of any planet or the sun.
It follows a hyperbolic (and bizarre) trajectory, that is, it will leave the solar system and never return.
It looks nothing like a comet, but it behaves as such. Oumuamua appeared in telescope images as a single point of light – if they first thought he was a comet, then they started to classify him as an asteroid.
He sped out space. This would be explained by the release of stellar gas on its surface when only the gravity of our solar system is taken into account.
Its elongated shape was determined by the variation of its brightness. It must be about 800 meters long and 80 meters wide (a shape never seen before).
It spins on two axes, completing a rotation every 7.3 hours, while rolling through space.
What is still a mystery?
Its appearance will remain unknown. The only image you have of Oumuamua is the one that shows a tiny point of light. The only thing that was possible to deduce is that it is elongated – nothing more.
What it is made of is another question that will remain unanswered. There may be gases like monoxide or carbon dioxide being ejected and forming a tail, but everything remains as speculation.
Where it came from, there is a “half answer”: from another star system in the galaxy. But which? Based on its speed, it is thought that Oumuamua may have come from a system with a young star or may have been roaming the galaxy for billions of years, and how do you know?
Where he is is just a projection. In January 2018, it became invisible to telescopes, even space ones. Now, Oumuamua’s future in space belongs only to him.