Oumuamua, and Our Search to Reach Our Strangest Visitor.

There is much we don’t know. We may have made extraordinary strides on understanding the limits and levers of reality in the past few hundred years, but we have more questions now than when we started, and far more questions than answers.

We do not know who we are, or indeed what we are. We cannot explain consciousness, nor say with any certainty what happens when that consciousness stops. We cannot explain what caused the leap from organic chemistry to life, nor hope to artificially reproduce it.

Neither can we explain what caused the universe to come into being. We can look backwards through time by gazing at the heavens above us, but only so far, What came before the Big Bang is purest conjecture.

Our experience, in practical terms, is extremely limited. We know the elemental composition of the universe largely because we have access to such elements on Earth. The structures these building blocks create, from molecules to mountains, are done in a standard fashion dictated by their very nature, and this behavior is true of the element wherever it is.

Our fundamental understanding of the universe depends on the fact that, were we to travel across the universe, we would encounter at our destination something physically, chemically and potentially biologically similar. Everything works the same everywhere, but this is an assumption.

Nice theory, then. There are two ways to check it, unless we are happy pointing telescopes at all our questions. One: we go out there and take a look ourselves, samples, analyses and all. This would be difficult and time consuming before the return journey was even contemplated.

The other would be to wait for the universe to come to us. And there are, occasionally, such interstellar visitors who come rocketing through our solar system, true aliens in terms of our experiences as a species.

We have never seen one to date. Until Oumuamua.

A Visitor from the Dark Beyond

Oumuamua is named for a Hawaiian word meaning “scout”, or more accurately “distant messenger”, and the naming is apt. A lone interloper into our solar system, flying in from “above” almost perpendicular to the orbits of the inner planets, she has appeared from nowhere out of the darkness of the universe beyond.

We discovered her only recently, on 19 October 2017. In truth we almost missed her, by the time we saw her she was already seven weeks past the point where it passed closest to the Sun: Oumuamua was powering out of the Solar System by this point.

For she was indeed “powering” out of our vicinity, and in fact Oumuamua was exhibiting all sorts of strange behaviors. For one, it was accelerating on its own, boosting itself away from us through some mechanism.

Most likely this is simply some icy aspects of the object’s surface melting during proximity to the Sun and generating jets of gas which serve to push the object. But it is eerie to see an entirely new phenomenon exhibit such unexpected behavior, nonetheless.

Then there is the fact that Oumuamua doesn’t behave like the other similarly sized “outgassing” bodies in a solar system: comets. The “tail” of a comet is the visible result of outgassing, and yet Oumuamua had no tail at all.

It is also a weird shape. Estimates vary wildly, but Oumuamua may be as long as 1,000 meters. However almost all agree that she is wildly elongated, a baguette-shape object pinwheeling through space.

Such an elongated shape is highly unusual for a naturally occurring object to have, and finding out what caused Oumuamua to be shaped that way could reveal some very interesting facts about our local part of the universe.

And through all this, Oumuamua is still there. We might have reached her, had we known more about her coming earlier. She passed only 24 million kilometers from Earth, five days before we ever knew she existed, and it is almost certainty too late now.

She has flown through the heart of the Solar System and is now outside the orbit of Neptune, heading for the constellation of Pegasus. Oumuamua will never return.

But for some she has shown the way, earning her name in an entirely new way. Our direct experience of the universe has been expanded, and therefore we have learned much.

Except we kind of haven’t, or at least we haven’t yet. Oumuamua is something entirely new, so new that the International Astronomical Union had to create a new classification of celestial body for her. She exists in a class of one.

All we have are observations upon which we can theorize mechanisms, chemistry, origins. We need to see more interstellar bodies passing through our solar system, which will allow us to refine our understanding of exactly what Oumuamua was. And thanks to Oumuamua we know more or less exactly what to look for.

Doesn’t make it easy to find tiny interstellar objects flying without a trail of gas nearby, but it can certainly help. And until then all we can usefully describe are her oddities: Oumuamua was unusually shaped, spun in a strange fashion, was capable of accelerating as if ejecting gas, but no gas ejection could be seen. 

Whatever Oumuamua truly looked like, whatever lies behind these unanswered questions, we will almost certainly never learn this from Oumuamua herself. But in knowing what to look for, we will be ready for whatever comes next, and then the race will be on to reach out and to find out.

Top Image: Oumuamua doesn’t have a tail like a comet, but vents something causing acceleration (NASA; ESA; Joseph Olmsted (STScI); Frank Summers (STScI) / Public Domain)