This artist’s impression shows the first interstellar asteroid: `Oumuamua. (European Southern Observatory / M. Kornmesser/ESO/M. Kornmesser)
Lucianne Walkowicz is an astronomer at the Adler Planetarium, and the 5th Blumberg Chair in Astrobiology at the Library of Congress.

The interstellar object known as ‘Oumuamua plunged into our solar system in 2017, leaving a trail of mystery in its wake. It appeared as a tiny point of light, millions of times fainter than the earthbound human eye could see. Teams of astronomers from across the world deduced that ‘Oumuamua was a reddish, somewhat cigar-shaped rock, spinning and tumbling in space on its path through our planetary system. As it swung past the sun, ‘Oumuamua seemed to speed up ever so slightly — something often seen in comets, which emit jets of gas that give them a little extra kick as they get nearer to the sun. However, even the deepest images of our interstellar visitor failed to reveal any evidence of these jets, and so its acceleration confounded the astro-paparazzi.

While ‘Oumuamua itself is gone, its story has been on a decidedly different orbit. In a news cycle that otherwise offers a relentless torrent of trauma and political intrigue, ‘Oumuamua appears and reappears, its faint glints reminding us that sometimes, we, too, crave a speedy escape from our immediate reality. 'Oumuamua fascinates us of because the questions it left behind: The void of what we don’t know gives us room to stretch our minds and wonder. While scientific knowledge is typically built from the grit of unglamorous measurements, it’s often the wilder possibilities that gain the most attention. Some would say that arguing for those seemingly out-there ideas is nothing more than exploring the full space of interpretation — but power dynamics limit who gets to voice that freedom of mental movement.

Much of the ongoing coverage has centered on the claim that ‘Oumuamua might be a defunct alien spacecraft, which has turned the spotlight onto one of the authors of that claim, Avi Loeb. Loeb is known for his idea papers — slim briefs that often straddle the space between essay and scientific journal article — that other astronomers typically greet with wry acceptance, recognizing that they are written to encourage the free expression of ideas, even ideas that arrive, like ‘Oumuamua itself, on hyperbolic trajectories.

Within the scientific community, outlandish ideas like Loeb’s can be divisive, primarily because claims that attract a lot of media attention can turn the conversation away from the definite facts we’ve worked hard to learn. Scientists who make big claims can be seen as capitalizing on media hype, and the rest of us sometimes blame the media itself for playing a part. If we’re being honest, though, we have to admit that everyone involved — not just journalists, but also academic and research institutions and even the scientists themselves — participates in the hype cycle.

Hype in science can be seen as an outgrowth of the larger crisis in journalism, as the precipitous decline in journalism jobs has meant that few news outlets employ dedicated science journalists. While many scientists blame hyped-up science news on a lack of journalistic expertise, the reality is more complex: As the bottom fell out for science journalism jobs, many science journalists were faced with the choice between battling it out as freelancers or using their skills to work in the communications offices of the institutions housing scientists — usually universities. There, they would be tasked with spreading the word about the results of new research happening at their home institutions.

While the writers themselves are genuinely excited to share these new discoveries, media attention boosts the institution itself, enhancing its reputation and opening up new funding avenues. Accordingly, no news release, however measured, is ever solely about the distribution of new knowledge. And yet these same documents still do help journalists (especially those without specialized training in science) identify what new scientific results might be transformative.

It’s here that the problem of hyperbole comes into play. Many astronomers are fond of what’s known as the Sagan standard: the saying that “extraordinary claims require extraordinary evidence.” By contrast, ancient rhetoricians such as Quintilian believed that extraordinary circumstances actually justify hyperbole, because it can express the inexpressible when, in Quintilian’s phrase, “no one is contented with the exact truth.” All hyperbole skates a thin boundary between elegance and extravagance, between capturing the incompleteness of our knowledge, and distorting the truth. Among scientists — and, in this case, astronomers specifically — the boundaries of how outlandish one can be are limited by our commitment to careful measurement and moderate interpretations. Hyperbolic ideas therefore need not leave the solar system entirely before they risk offending our sensibilities.

But does hyperbole actually shift our perspective on the possible at all? Over at the Atlantic, Marina Koren has written about how institutional prestige — in this case, Loeb’s position as chairman of the Harvard Astronomy Department, along with his long list of other accomplishments — can add a certain gravitas to a claim that might be dismissed if it came from somewhere else. But it also shapes who can get away with extreme ideas in the first place. Pushing the boundaries of plausibility comes with risk to one’s career and reputation, so while anyone can use hyperbole as a tool, the risk that one bears is substantially higher if you are not insulated by a name-brand institution, along with titles and accomplishments from adjacent name-brand institutions. Outlandish claims are, in some sense, a luxury concentrated in the hands of those who already possess other luxuries — a kind of academic weight whose heft accumulates with time. The fact that hyperbolic ideas remain a privilege is precisely what limits them as a tool for moving the boundaries of the possible. Truly innovative thoughts can come from anywhere — including, like ‘Oumuamua, from outside the system itself.

What lights the fuse of curiosity is specific to each person: For some it takes a spaceship, while for others, a strange rock will do. In my experience talking with guests at the Adler Planetarium, media attention is certainly a factor in why many people want to talk about ‘Oumuamua, but relatively few seem wedded to the idea of it being a defunct alien spacecraft. Most people are interested for the same reason scientists are: It came from outside the solar system! It’s weird! There is mystery! For any discovery, the most far-flung interpretation is always out there (whether someone writes a paper on it or not), much as the subject of a photograph exists outside the bounds of the picture itself. Moreover, outlandish ideas are not demons, called into being by someone voicing their name — we should neither fear them, nor give them more power than they’re due.

While there is no way of knowing what will become of ‘Oumuamua, its discovery is a harbinger of others yet to come: Near-future sky surveys, such as the Large Synoptic Survey Telescope, are expected to find other interstellar space rocks on their way past the sun. In the meantime, what moves the needle of our knowledge isn’t really hyperbole, but the fact that we happened to catch this particular rock as it made a brief appearance here, that we learned as much as we did.