In a July 2015 Nature commentary, Swedish physicist Jan Conrad urged colleagues to tighten requirements for declaring breakthroughs. Citing, for example, the famously false news that neutrinos might have exceeded the speed of light, he warned of consequences from “broadcasting seemingly extraordinary results to peers and the public before they are reviewed, or despite knowing that better data are just around the corner.” But what about results that are peer-reviewed, worthy to be announced, yet likely to inspire—or maybe incite—misleading enthusiasm and overstatement?
An artist’s impression of the newly discovered planet Proxima b. Credit: ESO/M. Kornmesser
It’s great for science outreach that some among the press and the public adore to engage questions about life elsewhere than Earth. Along those lines, a recent news incident involving the search for extraterrestrial intelligence (SETI) fits the pattern that Conrad indicted. The incident caused the Special Astrophysical Observatory of the Russian Academy of Sciences to issue a short, sober statement that began, “On August 30, 2016 there appeared a number of reports in different mass media on possible detection of a radio signal … associated with the activity of an extraterrestrial civilization; in this connection, we consider it necessary to make official comments.” The statement killed the wayward news story by announcing that although this “interesting radio signal” had indeed been detected, “subsequent processing and analysis … revealed its most probable terrestrial origin.”
But what about the nearly simultaneous media reaction to the peer-reviewed, eminently announcement-worthy Nature article “A terrestrial planet candidate in a temperate orbit around Proxima Centauri”? That paper presents itself without journalistic extravagance—though maybe it inevitably and unintentionally invites the extravagance that arrived anyway.
The paper reminds its readers that Proxima Centauri is the Sun’s closest stellar neighbor and calls it “one of the best-studied low-mass stars.” The 31 coauthors report “observations that reveal the presence of a small planet”—called Proxima Centauri b, or just Proxima b—“with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units.” The paper announces that this planet’s “equilibrium temperature is within the range where water could be liquid on its surface.”
It also observes that the “habitability of planets like Proxima b—in the sense of sustaining an atmosphere and liquid water on its surface—is a matter of intense debate.” It lists the “most common arguments against habitability” as “tidal locking, strong stellar magnetic fields, strong flares and high ultraviolet and x-ray fluxes.” But it also stipulates that “none of these have been proved definitive.” It concludes that a “warm terrestrial planet orbiting Proxima offers the opportunity to attempt further characterization via transits (ongoing searches), by direct imaging and high-resolution spectroscopy in the next decades, and possibly robotic exploration in the coming centuries.” The scientific conservatism in that phrase coming centuries has been lacking in press coverage that hopes for, or even presumes, imminently available interstellar exploration capacities.
An explanatory “News and Views” commentary appears in the same issue of Nature, seeking to widen and deepen general attention to these astrophysical research results. The commentator, astronomer Artie P. Hatzes, begins by recalling why exoplanet news can attract wide general attention. “Exoplanet discoveries trigger our imaginations,” he writes—omitting what he could quite sensibly have added: that they can also trigger journalistic extravagance. His opening continues: “What does the newly discovered planet look like and what are its characteristics? Could it harbour life and, if so, how many such habitable worlds are there in our Galaxy?”
Hatzes explains that Proxima Centauri belongs to the family of stars known as M dwarfs. With scientific restraint, he cautions that until “we understand what makes a planet habitable, it is better to say that” this particular M dwarf “lies in a temperate zone (the right temperature) rather than a habitable zone (the right conditions to support life).” He continues by offering a measured—by the standards of some in the media, anyway—summary of astronomers’ prospects for gaining further knowledge:
Studies of the exoplanet’s atmosphere could assess its habitability. One way to do this is by using a technique called transmission spectroscopy: if the planet passes in front of (transits) the star when viewed from Earth, its atmosphere would absorb the starlight while transiting, and so the spectrum of the starlight would contain a signature of the planet's atmosphere. But we currently do not know whether Proxima Centauri b is such a transiting planet—there is only a 1.5% chance that it is.
One could also attempt to detect the reflected or radiated light from the planet directly—this can be done only for nearby planets. Because Proxima Centauri is relatively close to us, such attempts have a reasonable chance of succeeding. In the distant future, an interstellar space probe might get a close-up look at the planet.
NASA’s Transiting Exoplanet Survey Satellite, which is scheduled for launch in 2017, will search for transiting planets around thousands of the closest M dwarfs. The planets’ atmospheres could then be characterized using the James Webb Space Telescope, scheduled for launch in 2018. In the next decade, we will learn much more about the atmospheres of exoplanets in the temperate zones of M-dwarf stars. Meanwhile, Proxima Centauri b gives astronomers their best opportunity yet to study such planets.
An informal, unscientific sampling of Proxima b news articles suggests that though most reporters try to exercise restraint, the media coverage in some cases earns criticisms comparable to those from Conrad—even though in this case, the results are peer reviewed—as opposed to premature or worse—and are framed as looking ahead in an orderly way to further research.
Some of the ensuing media coverage has been outrageous. The exoplanet news “could change life as we know it,” blared the UK’s Daily Mail in an article headlined “The eight foot aliens who live on ‘Earth 2.0.’” The subhead said, “Discovery of Proxima b just four light years away reignites bizarre 1950s claims beings from the area visit our planet.” The piece linked to an Inquisitr article explaining that the research results provide “evidence backing old conspiracy theory claims that there is a planet orbiting Proxima Centauri that is home to a humanoid species called the Cenos aliens.”
Much lower on the extravagance scale, Business Insider announced, “Astronomers just discovered the most important exoplanet in history.” The Guardian quoted an astronomer proposing something similar:
Ignas Snellen, a professor of astronomy at the Leiden Observatory calls Proxima b the most important planet found beyond the solar system since the first, 51 Pegasi b, was spotted by Didier Queloz and Michel Mayor in 1995. “This is the discovery of the year and possibly of the decade,” Snellen says. Not only does it mean an Earth-sized planet orbits our nearest star, it implies that other such worlds are common. “It will be our prime laboratory for the search for extraterrestrial life for the decades ahead. We have no idea whether life could exist on this planet, but the circumstances are likely to be much more favourable than on Mars,” he says.
Fast Company magazine—which sees itself as “the world’s leading progressive business media brand, with a unique editorial focus on innovation in technology, ethonomics (ethical economics), leadership, and design”—announced news of an “insanely close Earth-like planet that could actually support life.”
Insanely close? That perception of proximity underlies much of the journalistic extravagance.
Consider an online Washington Post piece by Rachel Feltman, who runs that newspaper’s “Speaking of Science” blog. At the top, the article links to a 76-second video, attributed to Reuters and headlined “Earth-like planet found just outside solar system.” Just outside? True, such terms are relative, and true, the universe overall is indescribably huge, but the fact remains that the Sun’s nearest stellar neighbor is 4.2 light-years distant.
Maybe another editor, not Feltman, captioned the video. In any case, Feltman herself says, cautiously, “Proxima b will no doubt be dubbed ‘Earthlike’ by many, but let’s not jump the gun. Here’s what we know: The planet, based on statistical analysis of the behavior of its star, is quite likely to exist. Beyond that, we know very little.” And this too: “Even if Proxima b has (or once had) an atmosphere and held water, the evolution of life is far from guaranteed. For one thing, we’re working with a sample size of one (the Earth) and have no idea how common the spark of life really is—even on planets that have all the same ingredients as the ones found at home.”
Feltman cautiously engages the proximity perception when she writes, “If Proxima b proves to be a real planet—and one particularly worthy of study—a visit wouldn’t be totally outside the realm of possibility. But even though Proxima is our closest neighbor, it’s still awfully far: NASA’s New Horizons probe had to travel 3 billion miles to get to Pluto and took nearly a decade to do so. At around 25 trillion miles away, a trip to Proxima b would be more than 8,000 times as long. At least one well-funded group is trying to develop the technology needed to propel a tiny probe into the Centauri system, but don’t hold your breath.”
Concerning that ambitious group, she links to her own April article “Stephen Hawking wants to use lasers to propel a tiny spaceship to Alpha Centauri.” It describes the vision of astrophysicist Hawking and Russian tycoon Yuri Milner to get a light-propelled nanocraft to that part of the universe “within one generation of launch.”
At Wired, science writer Sarah Scoles, holder of a bachelor’s degree in astrophysics, contributed “Y’all need to chill about Proxima Centauri b.” She sees general public excitement and delight over the news, but says it “feels premature, or even just outright incorrect.” She argues that the planet’s relative—in universe terms—proximity skews perceptions, including those of astronomers. Though she acknowledges that talk of interstellar travel sounds “pretty fringe,” she mentions the Hawking-Milner vision. She declares that the proximity, such as it is, constitutes a “news peg” and makes scientists “feel more comfortable passionately and publicly proclaiming interstellar intentions.” She also declares Proxima Centauri b “the first exoplanet that is also a physical destination” and announces high confidence in predicting that if a signal “came through … the governments of the world would come together to send some people there.” She doesn’t say how.
On 24 August, Gizmodo, linking to a Gizmodo article from April, announced that engineers are preparing “for an interstellar voyage to scope out Proxima b for signs of life.” Would that really be a voyage across a distance of 4.2 light-years? Readers who stop to chase the link to the April article find that it’s about the “$100 million research and engineering program” that was announced by Milner and Hawking, “seeking to lay the foundations for an eventual interstellar voyage.” That first step, the April article explains, “involves building light-propelled ‘nanocrafts’ that can travel at relativistic speeds—up to 20 percent the speed of light.” The April piece adds that at “such high velocities, the robotic spacecraft would pass Pluto in three days and reach our nearest neighboring star system, Alpha Centauri, just over 20 years after launch.” A quotation highlighted as a call-out in the August article glories that it “has become okay to talk about interstellar travel” and that people “are seriously considering it.” But only at the end does the August article make clear that the “interstellar travel” would involve only tiny robotic machines.
In a Washington Post commentary, science fiction writer Stephen Baxter underlines the reality that many readers and viewers emphatically intend to engage the question of life elsewhere whenever they can. He summarizes some of science fiction’s decades-long history of stories involving travel to the star nearest to our sun. Now that we know Proxima b is real, he writes, “the fictional speculation moves on to what it would to be like to go there.” His closing line observes, “Suddenly, the universe looks much more hospitable to life than it did just a few days ago.”
The Guardian piece that’s mentioned above closes with this:
“The importance of this system is as an inspiration,” says Chris Lintott, presenter of The Sky at Night and a professor of astrophysics at Oxford University. “There’s much work to be done to find out what this planet is really like, but the existence of a potentially habitable world just next door should inspire us to explore beyond our solar system. There are existing plans for small, fast-moving probes that could reach Proxima in a couple of decades, and I think just having a target to aim for will inspire more. Now we know it’s there, surely we have to go?”
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Steven T. Corneliussen, a media analyst for the American Institute of Physics, monitors three national newspapers, the weeklies Nature and Science, and occasionally other publications. He has published op-eds in the Washington Post and other newspapers, has written for NASA's history program, and was a science writer at a particle-accelerator laboratory.
