The already strange ‘Oumuamua just got a lot more bizarre as a new study has suggested that the interstellar visitor contained a large amount of hydrogen ice. Ever since it was first detected back in October of 2017, it has been surrounded by much mystery and confusion.
Where do we even begin with ‘Oumuamua’s bizarre characteristics? Well, first of all, it looks incredibly odd as it’s shaped like a cigar which is definitely unusual for space rocks. Additionally, it showed non-gravitation acceleration that was not the result of being pulled in by the sun or other large space objects. In fact, when comets accelerate, they usually spit out debris behind them when they heat up, but ‘Oumuamua never developed a tail. Not to mention the theory that it is an alien spacecraft.
Another recent hypothesis has suggested that it is just a piece of a planet that was ripped apart when it flew too close to its host star.
The latest theory, however, is just as fascinating as scientists believe that it was probably made of hydrogen ice. Greg Laughlin, who is a professor of astronomy at Yale University as well as the co-author of the study (which can be read here), said in a statement, “This is a new type of object, but it looks like there may be many more of them showing up going forward.”
Laughlin and Daryl Seligman, who is the lead author of the study and works at the University of Chicago, both said, “Hydrogen is the most abundant element in the universe, but we don't often see it in solid form; that requires extremely cold temperatures. But such temperatures exist in the coldest cores of giant molecular clouds, nurseries that give rise to stars and their associated planetary systems.”
Laughlin explained that as ‘Oumuamua traveled closer to our sun, it became warmer which caused its hydrogen to melt and quickly boil off of its surface. That would have also caused it to accelerate in addition to getting thinner resulting in its odd elongated shape. He compared this process to when we use a bar of soap and it thins out.
If their theory is correct, it would mean that there are many “hydrogen comets” travelling around space. “Their presence would be an accurate probe of the conditions in the dark recesses of star-forming clouds and provide a critical new clue for understanding the earliest phases of the still-mysterious processes that generate the birth of stars and their accompanying planets,” Laughlin noted.
While ‘Oumuamua has traveled well past Earth, astronomers are hoping to use what they’ve learned in order to find other similar space objects in the future.