The ‘distant place explorer’ or Oumuamua emerged in our solar system as the first known interstellar object to pass through our cosmic neighborhood . The theories regarding its origin have occurred since it was observed in 2017. What was Oumuamua? An alien ship as the controversial theoretical physicist Avi Loeb put it? A comet? The remains of a stellar shipwreck? The object defied explanation.
The puzzle remains undisclosed almost four years after its discovery. Or maybe not?
Mystery, solved?
Now, a pair of astrophysicists from Arizona State University (USA) are leading a study that brings to the table an interesting new hypothesis: Oumuamua is part of a planet similar to Pluto from another solar system that was broken off from its home about 400 million years ago.
The team found that it could explain much of what we’ve observed so far if the object were made of nitrogen ice, like the surface of Pluto. Apparently we weren’t even hitting the mark on its shape: it doesn’t have a cigar silhouette, but is flat as a pancake.
Scientists estimate that ‘Oumuamua first entered the solar system in 1995 . As it got closer to the Sun, it began to slowly evaporate. This process created its strange flattened shape (like what happens when we use a bar of soap for a long time) and explains why the object is accelerating as the Sun passes. It moved away a little faster than gravity allowed. And it’s something that happens when ice on the sunlit sides of comets vaporizes, giving them a small boost of speed like a rocket ship. But unlike comets, ‘Oumuamua did not appear to have a cometary tail.
What kind of evaporating ice could give you that ‘boost’?
Planetary scientists Alan Jackson and Steven Desch, who publish their results in the Journal of Geophysical Research: Planets , calculated the thrust on Ouamuamua if it were made of ices such as nitrogen, hydrogen and water and determined that the nigrogen ice was a perfect fit for this object. .
And since solid nitrogen ice has been observed on the surface of Pluto, it is possible that the mother planet of Oumuamua was similar. “We knew we had the right idea when we completed the calculation of what albedo (which tells us how reflective the object is) would make the movement of ‘Oumuamua’ match the observations,” says Jackson . “That value turned out to be the same as what we observed on the surface of Pluto or Triton, bodies covered in nitrogen ice.”
The researchers suggest that Oumuamua entered the solar system at a slightly slower rate than might be expected, indicating that it has not been traveling through interstellar space for more than 1 billion years.
“Until now, we had no way of knowing if other solar systems have planets similar to Pluto, but now we have seen a piece of one pass by the Earth,” the experts conclude.
Can we confirm this hypothesis?
Unfortunately, the interstellar traveler is already too far away to repeat observations and it is too small, so to completely close this enigma we will need new observatories, such as the Vera Rubin Observatory or ESA’s Comet Interceptor mission, that are capable of tracking all of them. interstellar objects passing through our solar system.
Referencia: A.P. Jackson and S.J. Desch. To see a world in a shard of ice: ‘Oumuamua as a fragment of N2 ice from an exo-Pluto. Lunar and Planetary Science Conference, March 17, 2021.
A.P. Jackson and S.J. Desch. 1I/‘Oumuamua as an N2 ice fragment of an exo‐Pluto surface: I. Size and compositional constraints. Journal of Geophysical Research: Planets. Published online March 16, 2021. doi: 10.1029/2020JE006706.
A.P. Jackson and S.J. Desch. 1I/‘Oumuamua as an N2 ice fragment of an exo‐pluto surface II: Generation of N2 ice fragments and the origin of ‘Oumuamua. Journal of Geophysical Research: Planets. Published online March 16, 2021. doi: 10.1029/2020JE006807.
