A long trapping expedition through our galactic neighborhood just snared one of its prime quarry: a planet about the size of the Earth in a stable and regular orbit at a distance from its star that makes liquid water plausible on its surface. That means just right, and thus smack in the Goldilocks zone. World press is perking up at the news from NASA and its scientific cadre, published in Science magazine. Thus we meet Kepler-186f. That f means fantastic and more exactly that it is the fifth planet out from a star named Kepler-186. Star names gain a b to designate their first known planets, c for a second, and so on. At least half a dozen press releases and a streamed press teleconference helped spur reporters along (see Grist below).
It is notable that Science, a journal usually faithful to reporting data and compelling conclusions, chose as cover art a made-up artist's impression of imaginary surface detail. Highlands incised with dendritic drainage channels, seas filling the lowland, hints of tectonism, weather systems, archipelagos ….oh my. The cover's just the start. Another illus proferred by the journal's Sci-Pak for journalists shows an imagined lake up close with a freakin' forest around it. Made up folks, made up. Not that Science ever said these eye-candy pictures are particularly instructive.
This is big news. It is not quite, uh, to mention a cliche I loathe but have to admit does have meaning, a holy grail. That'd probably required better instruments than astronomers yet have, ones able to get fairly detailed atmospheric spectra from this little world and maybe even imaging systems that can spot features in its clouds or on its surface. Such things to come could show hints of chemical disequilibrium or other irregularities plausibly attributable to metabolic meddlings by living things. That'd be a holy moly, a holy crapola, a holy something for sure. It'd not match a radio signal from an alien civilization, but let's not be greedy. Even without life to report, this news nonetheless is a highlight. It is a triumph for the Kepler Telescope. That device's almost miraculously sublime photodetection gear – until a gyro blew out last summer – measured the dimmings of stars as planets cut across and slightly shadow their faces as seen from here on Earth. It is amazing what smart people can glean from tiny variations in brightness. It more broadly is a satisfying achievement for the larger army of astronomers in the exo-planet game going back decades. It was 1995 when we got the first, independent reports of exo-planets.They came via a different way to spot stars with planets that we can rarely directly see. Doppler shifts in the star's light betrayed planets that tug their parent stars this way and that. Well beyond 1,000 planets from all search methods are now known. Most are in freaky and sterilizing orbits. They include scads of so-called hot jupiters zipping around their stars in just hours or a few days, getting scalded. Now the astronomers finally got one that could be – while probably a bit colder than here -comfy enough.
Read some of the coverage. It has detail on the nature of red dwarf stars, their abundance, and the confirmation via this discovery that the cosmos surely has many planets whose vitals resemble those of our Earth. Several stories use genuinely instructive illus.
- NYTimes – Kenneth Chang: Scientists Find an 'Earth Twin' or Perhaps a Cousin ; He provides a short answer to one question I had right along. This world is about 10 percent broader than Earth but do we know its mass? 500 light years seems fairly close. But Chang says it is too far away to tell (presumably via doppler measurements). His story also explains the fair chance that despite its size and orbit, this one could still be very low on the habitability scale.
- ScienceNOW – Yudhijit Bhattacharjee: Almost-Earth Tantalizes Astronomers With Promise of Worlds to Come ; Red dwarfs are so stable for so long, this explains, that this planet might be billions of years older than our sun with correspondingly more opportunities for life to have arisen and evolved to great complexity.
- Nature.com – Alexandra Witze: Earth-sized exoplanet spotted in star's habitable zone ; Alex makes explicit which of Earth's specifications is not at all matched by this newly confirmed world – to be a full Earth analog a far off planet has to go around a sun-like star. Our sun is a G type. Yes, our star is a dwarf. But M-dwarfs (aka red dwarfs) do not make the cut.
- Washington Post – Meeri Kim: Earth-size, 'Goldilocks-zone' planet found in distant solar system ;
- Space.com – Miriam Kramer: Found! First Earth-Size Planet that Could Support Life ; Hmm. This hed is not quite right. It is the first Earth-size planet that one cannot compellingly label as unlivable based on what the experts know so far. Story is fine. Space.com repackaged all the stuff it could into its own video version of the news, too. I had to sit through an ad first, that I'd seen on TV too many times, of Mark Cuban escorting very tall retired men to his living room couch for a basketball game and who block his view. The video after that is a good one.
- also at Space.com – Mike Wall: Kepler-186f could be "Earth's cousin,' say astronomers.
- Universe Today -Jason Major: Kepler Has Found the First Earth-Sized Exoplanet in a Habitable Zone ; Nice job. Partly because this old timer appreciates the hed's "earth-sized" usage over the above, first Space.com story's "earth-size." Major calls is a 'eureka' moment, and that's fine too.
- Los Angeles Times – Amina Khan: Meet Kepler-186f, the most 'Earth-like" planet ever found ; This supposed rocky planet got an apt endorsement in this quote from a pioneer in the planet hunting business, Geoffrey Marcy at UC Berkeley, who told her the evidence is rock solid.
- San Francisco Chronicle – David Perlman: New planet discovered that just might hold life ; Nice touch – Perlman writes that while this planet is perfect for fiction writers to fix upon for speculation it is an abode for life, "most astronomers would never make a leap to such a subject." Actually they would. Just not in refereed papers so much. But in press conferences…..
- AP – Alicia Chang: Astronomers Spot Most Earth-Like Planet Yet ;
- CNN- Josh Levs: NASA discovers Earth-sized planet that may sustain life ; One must be careful with metaphors that might mislead. This lede says "it's like finding a needle in a universe-wide haystack"and that's too much. Yes, it was a hard search, but not that hard. The search area is not even close to universe-wide. It is a small but starry stretch of our own galaxy in roughly the direction of the constellation Cygnus. Second, while the famous haystack needle was just one needle, the lesson from Kepler-186f is that the universe-wide may easily have billions upon billions of Earth-like planets.
- Denver Post – Kristen Leigh Painter: Earth-sized planet dubbed Kepler-186f may be best hope for life ; Good to see a regional paper staffing news like this. But one suspects the staff there is under the now-common edicts for hometown newspapers: keep it local. This piece, after a good general roundup on the big news, slides at its bottom into the local angle. Which is that a Colorado company, Ball Aerospace, is deeply involved in finding new jobs for Kepler spacecraft now that it cannot keep its eye pointed fixedly for long enough at one thing to keep up its original planet hunt.
- Christian Science Monitor – Liz Fuller-Wright: Earth-sized plaent discovered: Is our galaxy teeming with habitable worlds? Okay, here's a deeply nonessential usage quibble. "Teeming" means swarming, filled with, etc. Like maggots on a two-day-dead gopher, squirming around upon one another. The Golden Horde threatening Constantinople, that was probably a teeming thing to see. Billions of Earthlike planets is a lot of them. Spread out among the far more billions of unearthly worlds and spaced far from one another they however do not make for a teeming situation.
- …could go on, time's short.
*UPDATES – More accounts, starting with two of the most reliable, usual suspects in space science writing and a third who has been writing about most everything for decades:
- National Geographic – Dan Vergano: Kepler Telescope Discovers Most Earth-Like Planet Yet ; For background, Vergano links to one of his own stories on the Kepler bonanza of recent years. The new yarn recounts the highlights of that history that set the stage for this best-yet world that has an Earthiness smell to it. He has one aspect I missed seeing, if it's there, in other stories. Because this planet is a bid wider and heftier than Earth – with perhaps half again the mass – its internal heating from radioactive decay will have been greater and may still be. Big melts toward its core could mean more dynamic tectonics, meaning in turn plenty of volcanism to keep the atmosphere thick, rich with active molecules, and perhaps suitable for evolution of life. Also here is a hint that among candidate planets still under analysis are some orbiting Sun-like stars at distances similar to Earth's orbital radius.
- TIME Magazine – Michael D. Lemonick: Almost Earth: A Newly Discovered Planet Could Be a Lot Like Ours ; Slick job ot telling readers that Kepler is still finding planets even though it is badly on the fritz – and how that can be. Also here is a hint to how Kepler's analysts can be so sure this new Earth-ish one is definitely a planet yet have taken so long to extract that conclusion from the data. Lemonick pays Kepler's work close attention. The story has multiple links leading to other stories expanding on aspects of the work and its background. Most of them are Lemonick's own.
- Wall Street Journal – Robert Lee Hotz: Earth-Size Planet Where Water Could Exist Discovered ;
- The Independent (UK) Steve Connor: Earth 2.0? Astronomers reveal Kepler-186f, the latests planet in a habitable 'Goldilocks zone." ; Most reports note that the planet will be colder than Earth. Hotz makes the point more precise, "..it likely receives about the same amount of light as Mars in our own solar system." Of course a bigger planet than Mars can hold a thick atmosphere longer, so the comparison is not perfect, but it makes it easier to digest than an abstract generality.
- Ars Technica – Akshat Rathi: The most Earth-like planet is only 500 light years away ;
- Spaceflight Now – Stephen Clark: Earth's 'cousin' planet lies 500 light-years away ; Fairly routine news summary up top, but the patient reader is rewarded toward the end. One finds a concise tangent on why planets of red dwarfs are easier to spot than those around larger stars – partly because there are so many red dwarfs but also because the stars' dimness makes more apparent episodes of shadowing by planets. Plus, the smaller size of such systems makes transits a bit more common. Orbital periods within habitable zones are also shorter, meaning more frequent transits to analyze. Thus such planets may be the first, with equipment yet to come, to be studied for explicit signs of life.
- Washington Post – Meeri Kim: Earth-size, 'Goldilocks-zone' planet found in distant solar system ; Good job. Kim, based in Philadelphia, is a freelancer who writes often for the Post and the Philadelphia Inquirer. It says here she was, until last year, also a grad student in Biomedical Optics at Penn, and got her PhD in August. And has joined NASW too. All fine but even though she is a regular, one can't help observing that not long ago the Post covered all big astronomy stories with staff writers. Kim is a live one. Read her account of a AAAS mass media fellowship at the Inquirer where on day one editors threw her right into the deep end. For this planet story, her first quote is from a scientist not on the discovery team. Everybody else, pretty near, led with quotes from the press conference (or maybe the press releases).
- Arizona Daily Star – Tom Beal: Finally – NASA's Kepler finds an Earth-sized planet in the 'Goldilocks zone' ; Beal is among the more prolific regional newspaper science writers still in harness. We haven't dug down deep enough lately to find his stuff. His story stands out for its emphatic rejection, as fantasy, the pictures that accompanied the news. He wrote, "To be clear, this planet probably looks nothing like the artist's conception of it that accompanies the article announcing it in Science. The illustration shows a Minnesota-like terrain with a lake surrounded by trees that are oddlycolored by the weak visible light emanating from a red sun."
- ….whew. This is a news supernova. Could go on for hours digging up more.
Grist for the Mill: NASA-Ames Press Release ; SF State Univ. Press Release ; SETI Institute Press Release ; Penn State Press Release ; Univ. of Notre Dame Press Release ; Gemini/Keck observatories joint Press Release ; Univ. of Michigan Press Release ;