The distance between stars is quite large, but our first known intercropping visitor had plenty of time to get here. Oumuamua ‘left its home solar system millions of years ago, joining ours back in 2017. Scientists had a hard time sorting out’ Oumuamua, and there is some disagreement still there. Two astronauts from Arizona State University have published a paper that says ‘Oumuamua is not an asteroid or a comet, but a pancake-shaped piece of a Pluto-like world.
Scientists discovered ‘Oumuamua in the fall of 2017, but it was already out of the solar system at that point. We know ‘Oumuamua came from a different star because of how fast it was, and at first, astronomers assumed that it was a comet based on what we think we know about structure of solar systems. However, ‘Oumuamua, properly called a coma, did not have a tail that you would expect for a comet. Just as the conventional idea was beginning to shift to Oumuamua to resemble an asteroid object, an ESA study showed that the object’s path was being suppressed by a deletion that was too weak to generate coma. . So maybe a really old comet?
Alan Jackson and Steven Desch from ASU have designed a model that could change the way we think about the appearance of Oumuamua. According to their analysis, ‘Oumuamua is a planetary particle made up largely of frozen nitrogen. Yes, an exoplanet floats through our solar system.
The model from Jackson and Desch paid attention to the size, shape, shadow and movement of the object. In addition to the revised pancake-like form, they decided that frozen nitrogen was the best match for what they saw, and we have an idea of where to get a big chunk of frozen nitrogen thanks to to New Horizons. When that probe flew past Pluto, scientists got some interesting observations about the ice surface which was mostly nitrogen. Jackson and Desch claim to have hit the surface of Oumuamua’s free-flowing world of free radicals and removed it from its home solar system.
At the end of all this, we still don’t know for sure what Oumuamua is. Avi Loeb at Harvard believes that we cannot control artificial origins, and he has a book describing his feelings on the matter. I don’t think it would be unreasonable to call this an outside opportunity, but it is is able. ‘Oumuamua is exiting our solar system, never returning. So, this could be a mystery we can never solve. Our best bet is to understand ‘Oumuamua could be on the lookout for similar products that we can examine in more detail before moving into the deep space.