Although long gone, the origin of “Oumuamua” in the cosmos remains a point of contention among scientists.
A study published in the journal Nature has proposed an explanation for the origin of Oumuamua, suggesting that it is merely a natural object, not a product of extraterrestrial origin as many have speculated. However, this study has failed to convince a Harvard University astronomer.
Oumuamua is thought to be a hydrogen-rich ‘ice block’. (Image: Vice).
Discovered in October 2017, Oumuamua quickly captured the attention of astronomers due to its unusual shape and behavior.
Oumuamua is elongated and flat like a cigar – a shape rarely seen in meteoroids. Additionally, it tends to move in a straight line rather than following an elliptical path influenced by the Sun’s gravity. Notably, Oumuamua’s speed is significantly greater than that of typical meteoroids and it accelerates as it approaches the Sun, as if propelled by an additional force.
Typically, comets can exhibit similar movements by releasing gaseous material and forming a comet tail. However, Oumuamua lacks a “tail.” Special telescopes have detected no signs of this object releasing material like a comet, whether it be water vapor or dust.
Even though it has long disappeared, the origin of Oumuamua remains a mystery. Many theories have been proposed, with a notable number of people believing that this object is a product of extraterrestrial life.
However, in a recent study published in Nature, scientists have presented arguments showing that Oumuamua is simply a natural object. Specifically, they argue that Oumuamua is actually a “hydrogen-rich ice block.” As it approached the Sun, the high temperatures caused the hydrogen to vaporize, releasing energy that accelerated the object while also eroding it into its unique shape.
The new study argues that a small amount of hydrogen gas caused Oumuamua to accelerate without forming a “tail”. (Image: Getty Images).
Calculations indicate that a small amount of molecular hydrogen can create significant acceleration, increasing Oumuamua’s speed without forming a comet’s “tail.”
This is considered a reasonable explanation for the mysteries surrounding Oumuamua, reinforcing the hypothesis that Oumuamua is a remnant from a planetary body similar to comets in the Solar System.
“This explanation could end the fierce debate that has lasted for the past five years regarding Oumuamua, while also opening new avenues for exploration about planetary formation,” stated Darryl Seligman, a postdoctoral researcher at Cornell University and co-author of the study.
However, Dr. Avi Loeb from the Department of Astronomy at Harvard University disagrees with this argument.
According to Loeb, for Oumuamua to reach speeds of up to 322,000 km/h as observed, the hydrogen inside the ice block would have had to completely vaporize, which would also release a large amount of oxygen molecules, implying that a “tail” of Oumuamua should still be visible.
“Keep in mind that Oumuamua is the size of a football field (100-200m). How could all the hydrogen from depths of tens of meters escape while leaving behind a pure oxygen-containing object? This is unbelievable,” Loeb remarked.
Loeb stated that only artificial spacecraft could exhibit such “behavior” and shape as Oumuamua. For instance, 2020 SO – a rocket launched by NASA in 1966, which was later forgotten and rediscovered in September 2020.
“These authors suggest that it is a special type of comet even though it has no ‘tail.’ It’s like saying an elephant could be a zebra without stripes,” Loeb said.
