A Billion Years In Interstellar Space: What We Know Today About ‘Oumuamua
“The incredible conclusion isn’t just that ‘Oumuamua came from outside
of our Solar System, but that this was both rare and common. For an
individual object, like ‘Oumuamua, it will likely never come this close
to another Solar System again. Only once every 100 trillion years — some
10,000 times the current age of the Universe — will it pass so close to
a star. As scientist Gregory Laughlin put it, “this was the time of
But for our Solar System, because of the sheer
number of objects like this flying through the galaxy, we probably
experience a close encounter like this around a few times per year. 2017
marked the first time we saw such an object, but we’ve likely gotten
billions of them over the course of our Solar System’s lifetime. Some of
them, if nature was kind, may have even collided with Earth.
There may be as many as ~1025
of objects like this flying through our galaxy, and every so often,
we’ll get lucky enough to encounter one of them. For the first time,
we’ve actually seen one of them for ourselves.”
In 2017, our Solar System received a visit like never before: from an object originating from interstellar space. Likely ejected more than a billion years ago from a foreign solar system, it happened to pass within even the orbit of Mercury, only becoming visible to our telescopes when it came within 60 lunar distances of the Earth.
But we found it, observed it, and learned everything we could about it. What do we know, today? Spoiler: it’s not from aliens.
‘Aliens’ Is Not A Scientific Explanation For Interstellar Asteroid ʻOumuamua
“We often say that extraordinary claims require extraordinary evidence, and in all of these cases the evidence is very, very ordinary indeed. It’s worth keeping our mind open to the possibility that there’s more out there in the Universe than we presently realize, but not to embrace those possibilities as likely in any way whatsoever. When you leap to explanations that are fantastic, it’s all too easy to forget about the most likely explanations, which often involve nothing more than the natural phenomena already present and well-understood in the Universe we know.
In the case of interstellar interloper ʻOumuamua, we should be looking at the natural explanations first and foremost, not speculating about something for which the only evidence is our own wishful thinking. After all, what can be asserted without evidence can — and should — be dismissed without evidence.”
When you find a new phenomenon in the Universe, one that you’ve never seen before, the opportunity to discover something new about your reality is unparalleled. Oftentimes, you’ll try to use what you know to infer what behavior you expect, but it’s usually just a first-order, naive approximation. Until you collect enough data, find enough objects that fall into the new category, and study them with the required precision and detail, you’ll merely be speculating about what’s going on.
Last year, our Solar System got a visit from an interstellar interloper, marking the first time that’s ever happened. It’s been an interesting ride, full of interesting science and fascinating findings. Which is why it’s maddening that the one time it makes news is when a couple of scientists from Harvard take off their scientist hat and run headlong into sci-fi speculations.
For what I’m sure won’t be the last time, invoking aliens as an explanation for what you don’t understand isn’t science. Don’t fall for it. Get the facts instead!