Astrogator's Logs

New Words, New Worlds
Artist, Heather Oliver             

Slouching to the Right of the Drake Equation

And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?

— William Butler Yeats, Second Coming

The last few years have been heady for planet hunters. First the hot Jupiters; then the will-o’-the-wisp Glieslings and their cousins; and in the last year, the results from the Kepler mission which detected planetary systems in the low thousands; one of these is Kepler 22.

Kepler 22 is a G5 type star (our sun is G2, about 10% bigger and hotter) 600 light years away with a planetary entourage. For anyone who was in a sequestered jury room or a silently running nuclear submarine, what got splashed across the news media on December 5 was the confirmation that one of the Keplerings is a super-Earth (2.4 times the radius of our planet) that is solidly within the habitable zone of its primary – habitable defined as the region where water can remain liquid. It circles its primary in 289 days and its estimated average temperature is a balmy 22 C/75 F if (big if) it has an atmosphere thick enough for a mild greenhouse effect.

That’s what we know, and it’s important and exciting enough. Here’s what we don’t know, which makes the exclamations of “Twin Earth!” annoying: we don’t know its mass (though the wobble velocity puts an upper limit of 36 Earth masses on it), its composition, the composition of its atmosphere or if it has any moons. Equally annoying are the suggestions to name it The Christmas Planet or the barely less mawkish Hope, right down there with the naming of putative Gliese 581g something like Betty (not even Elizabeth, which at least would celebrate an unforgettable historic figure, plus several literary ones).

The Kepler findings are pinning down the still-loose middle terms of the Drake equation by strongly indicating that most suns have planetary systems, and most planets are of the small rocky variety. Of the approximately 2,000 systems Kepler tentatively identified, about fifty have planets within the habitable zone, of which perhaps ten are “Earth-like” (loosely defined).

Half a percent may not sound like much. But given the quarter trillion suns in our galaxy, the numbers mount up quickly. Plus, of course, the size and location of the newcomer inevitably raises expectations: if Kepler 22b is rocky and has decent amounts of water and a reasonably thick atmosphere, the probability of life moves into the “likely” zone. So it’s not surprising that the Allen Array turned its dishes in the direction of Kepler 22 (no requests for Warren Zevon yet, but the night is still young) – or that the concept art is coming in thick and fast.

It is a great pity that Kepler 22b is so far. Even expeditions with quasi-exotic propulsion systems (or exceptionally nice humans in flawless arkships) would take a long time to reach it. But the lengthening list of not-quite-Earths is a powerful enticement not to abandon the faltering beacon of space exploration. Once again, I will close with what I said about Gliese 581g:

“Whether [Kepler 22b] is so hospitable that we could live there or so hostile that we could only visit it vicariously through robotic orbiters and rovers, if it harbors life — even bacterial life, often mistakenly labeled “simple” — the impact of such a discovery will exceed that of most other discoveries combined. Unless supremely advanced Kardashev III level aliens seeded the galaxy like the Hainish in Ursula Le Guin’s Ekumen, this life will be an independent genesis, enabling biologists to define which requirements for life are universal and which are parochial.

At this point, we cannot determine if [Kepler 22b] has an atmosphere, let alone life signatures. If it has non-technological life, without a doubt it will be so different that we may not recognize it. Nor is it a given, despite our fond dreaming in science fiction, that we will be able to communicate with it if it is sentient. In practical terms, a second life sample may exist much closer to home — on Mars, Europa, Titan or Enceladus. But those who are enthusiastic about this discovery articulate something beyond its potential seismic impact on biology and culture: the desire of humanity for companions among the sea of stars, a potent myth and an equally potent engine for exploration.”

Images: 1st, one of the four Kepler 22b imaginings by space artist Ron Miller. 2nd, comparison of Sol and Kepler 22 (NASA/Ames/JPL).

41 Responses to “Slouching to the Right of the Drake Equation”

  1. Zarpaulus says:

    I’m starting to get jaded by all the overhyped “Earth 2s” that have been found lately.

  2. Athena says:

    Call it “the asymptotic approach” to finding Earth 2! In fairness, though, finding earth-sized planets is very hard, and so is ironclad confirmation of their existence. These wobbles are tiny and have to be line-of-sight. That’s why the first batch of exoplanets was a slew of close-orbiting Jupiter-sized ones.

  3. andy says:

    It’s difficult to know what’s going on with Kepler-22b: the Kepler website gives an upper limit of 124 Earth masses, while the Extrasolar Planets Encyclopaedia gives an upper limit of 35 Earth masses.

    In the case of the 124 Earth mass limit, all that essentially rules out is an iron planet, while the 35 Earth mass limit looks roughly like the expected mass you’d need for an Earth-composition planet (after you’ve taken into account the additional gravitational compression). Neither of these hypothetical planet compositions seem like a particularly plausible outcome of a planet formation process: figuring out how to prevent a planet nearly twice the mass of Neptune from accumulating a lot of volatiles would be an interesting challenge!

    My guess: either a small version of Neptune, or perhaps a waterworld. Anyway even if it is not a Neptune-analogue, the planet should have managed to outgas and retain a very substantial atmosphere: the kind of moderate greenhouse you’d need at a 10% greater-than-Earth level of insolation seems to me to be very unlikely. I’d say the claims of habitability are very premature for this one… there have been far better candidates for habitable exoplanets presented previously.

    As for names, I’d rather know a bit more about these worlds and their characteristics before applying names to them: certainly there has not been a good track record of suggested exoplanet names so far. “Goldilocks” for the massive gas giant orbiting 70 Virginis (at one time thought to be close to the habitable zone due to an erroneous parallax in the Gliese catalogue) is merely the most ridiculous of these.

  4. Athena says:

    Yes, there’s not enough really hard data to reach definitive conclusions; I’m braced for a major qualification of Kepler 22b, as was the case with the Gliese 581 family. Instead of Goldilocks, this is starting to resemble The Boy Who Cried Wolf. As I said earlier, the difficulties of confirmation are formidable and space exploration venues need to feed the public’s endless appetite for new candy. But overselling makes backlash stronger.

  5. Walden2 says:

    No doubt one gets more funding et al if you declare that you have found Earth 2 rather than Jupiter number 2386.

    And while I say this somewhat rhetorically, why are we looking for other Earths? Shouldn’t we be searching for truly alien worlds, which would be a lot more exciting and interesting in my view. Those megaplanets that orbit their suns in just a few days and must be thousands of degrees hot aren’t bizarre and interesting enough? Almost no one expected them before their official discovery in 1995.

    Do people really think we are going to send out a colony ship the day that a real Earth-like exoplanet is found? NASA won’t even commit to a manned Mars mission in the next few decades, let alone a manned interstellar voyage. The lack of imagination here is both staggering and saddening.

  6. Asakiyume says:

    I really appreciate reading your take on these discoveries because you’re able to wade through the hype and present a realistic assessment–and yet at the same time you retain hope and enthusiasm.

  7. Walden2 says:

    And oh yes, Athena – thank you for finding some artwork of Kepler-22b that did *not* come from the NASA art factory. Not that I think their work is bad, I just got tired of seeing the same speculative pieces over and over with every article on the subject. Very refreshing, even if it too is totally wrong, like how does Ron Miller know if it has three moons? :^)

  8. Athena says:

    Thank you, Francesca. Neither uncritical acceptance nor blasé ho-humness does justice to this. It’s a major discovery without the gilding, which in fact diminishes its importance.

    You’re welcome, Larry! I agree about the lack of imagination and the constant rush to shoehorn results into known paradigms. Actually, Ron Miller did four different versions of Kepler 22b (I’ve amended the sentence in the essay to reflect this fact). You can see them all here.

  9. andy says:

    Yes this definitely has a “Boy Who Cried Wolf” air to it…

    What frustrates me a lot in all these announcements is that there has already been a lot of theoretical work done on planet habitability, but as soon as planets started to be found that were vaguely close to these requirements all that got jettisoned in favour of “these effective temperatures look nice”.

    Gliese 581c was a case in point: anyone who’d bothered to compute the insolation with the inverse-square law (pretty much the simplest calculation you can do in all this) would have realised it was more strongly-irradiated than Venus, but hey the effective temperatures looked quite nice so we got a load of hype about habitability.

    Incidentally I found the reason for the discrepancy between the mass limits for Kepler-22b in the discovery paper: 35 Earth masses is 1-sigma, 124 Earth masses is the 3-sigma limit.

  10. Athena says:

    That makes sense — upper/lower limits, given the measurement uncertainties. Also, I agree with you about the habitability requirements. I recall making a similar point about the surface life on Avatar’s Pandora. So close to a gas giant, it should be tidally locked, awash in radiation and its surface life (if any) should have sported thick carapaces and similar protective adaptations. Europan life shielded under ice and water, that’s a different story.

  11. Walden2 says:

    Even more so about Pandora being so close to a gas giant: Massive quakes, many active volcanoes, and more meteorite/comet impacts. Which means the life on that moon would have been simple and tough at best, probably not something a human Marine would want to get involved with.

    Even in Io’s sky Jupiter does not loom as large as Pandora’s planet does. So that alien place should be a geologically hostile mess. But huge gas giants in one’s heavens always look cool, and that is what counts. Even the first Star Trek film committed that sin with their vision of Vulcan at the beginning of the film when Spock is going through Kolinar. At least the planet of logical beings had lots of visibly active volcanoes and pools of boiling lava. Funny, though, how Vulcan’s big planet/moon disappeared later on as the series progressed in its new incarnations.

    Regarding Kepler-22b, I heard at least two news radio items, one of them NPR, where the announcer said that no expeditions would be sent to that alien world any time soon due to its 600-light year distance from Earth. One of them was also flabergasted at how we could know that Kepler-22b was 72 degrees F.

  12. Athena says:

    Re: Pandora — exactly. This is what I wrote in my first article about Avatar: “A moon as close to a gas giant as Pandora is would be awash in radiation and wracked by earthquakes and volcanoes like Jupiter’s Io.” Ditto for most Star Wars planets.

    As far as Vulcan goes, they pictured the planet circling a red(dish) sun, which would mean the usual — smaller habitable zone, probably tidal lock, non-stop hurricane-strength winds. The overall worldbuilding, including the attributes of the humanoid inhabitants, does not bear even remote scrutiny.

  13. andy says:

    Regarding worldbuilding, I think Io gets brought up way too often in the discussion of geological activity on gas giant satellites without considering other moon systems: Mimas and Enceladus make an interesting counter-example to the idea that merely putting a moon closer to the parent planet will increase the activity. Io may well be a special case due to the 1:2:4 Laplace resonance with Europa and Ganymede that acts to keep pumping Io’s orbital eccentricity against the tidal circularisation (the heating is essentially a dissipation process). Without this configuration Io’s orbit would be able to circularise further and the heating rate would die down.

    Similarly the idea that tidally-locked planets will have perpetual hurricane-strength winds at the surface. Sure in the upper atmosphere were heat transport is inefficient you would expect some very rapid winds, but near the surface the temperature gradient is going to be less (otherwise the atmosphere/hydrosphere is vulnerable to collapse by freezing on the darkside), particularly if you’ve got ocean currents also transporting heat around. This seems to be borne out by simulations, e.g. this paper, which if I’m interpreting figure 4 correctly depicts extremely high winds in the upper atmosphere but much less severe conditions at the surface. Weather patterns on such a world would certainly be unfamiliar though.

  14. Athena says:

    Results of simulations change depending on input parameters. Neil Comins does an exercise where he changes one Earth parameter — from a different-size moon to a crust of a slightly different thickness or metallicity. Each time the outcome is significantly different. Every planet and planetoid is a special case. That’s why on-site results from probes are so vital.

  15. Christopher Phoenix says:

    We really don’t know what the surface conditions of distant exoplanets are. SF writers used to think that Venus might be an “twin Earth” with a planet-spanning tropical rainforest, based on it having a similar mass to the Earth and a substantial atmosphere. A distant exoplanet we know only through the minute tug it exerts on its parent star might be a Venus-analogue rather than an Earth analogue, although Kepler-22b is probably a mini-Neptune instead. At this point, we know nothing about the surface conditions of Kepler 22b. The news media should hold back announcements of a “Twin Earth” until we actually confirm the existence of a biosphere on an exoplanet. Until then, scientists and artists are simply speculating on the possible surface conditions of promising exoplanets.

    If if we find truly habitable “Earth analogues”, the life forms on these planets will probably be found to be quite different from terrestrial organisms. The nice thing is that artists can speculate on the matter today, although it is almost certain that their visions are not entirely accurate.

    I prefer truly alien worlds in art. A Disney animation from 1957 has good examples of truly alien organisms on a wetter and warmer Mars. The film imagines plants that migrate to find richer soil, eat other plants, or even eat themselves (how is that supposed to work!?). Martian animals enshroud themselves in thick insulation, live underground, or close up like a snail to survive dust storms. Perhaps, however, some martian organisms feed directly on minerals, eating through rocks with powerful digestive acids, leaving fantastic sculptures behind. A ballont, or lighter than air animal, propels itself with jets of air.

    Life on Mars is a ceaseless struggle for survival. A flying creature behaves like a burning glass, killing its victims by focusing sunlight on them before flopping upon them (living death rays!). Devastating creatures enshroud their prey in poisonous gas, while an ominous ultrasonic being shatters its prey with focused beams of sound (another living death ray!). I’m not sure if I’d want to go for a walk on Mars now…

    Even more exotic possibilities are suggested- a entirely new chemical pattern of life based on silicon could exist on Mars. Living crystal spires grow to enormous heights during the day, only to shatter in a crescendo of destruction at the onset of the cold Martian night.

    Perhaps, just as we cannot conceive of intelligent life totally unlike our own, our Earth-trained minds will be unable to understand the phenomenon that exists on this strange new planet. Or maybe someone slipped a psychoactive drug in the astronauts meal, and the last scenes of the clip are a drugged induced vision…

    I like the creature that acts like a burning glass- that’s a rather original method of catching prey. Could it exist? I have not done an in-depth examination of the idea, but some of the bizarre methods of survival creatures use on Earth would sound fantastic to someone who had never seen them. The ballonts are pretty neat. I also like the rock-eaters, mostly for the fantastic sculptures they leave behind.

    The living crystals are fascinating, especially the fact that they shatter every nightfall- but I’m left wondering how a crystal can be “alive”. Are they actually organisms with a crystalline structure? Do the crystals have interior channels that pull minerals up through the crystal? Or are the crystals simply the by-product of some extraterrestrial chemical reaction, rather than being “alive”? How can they grow so fast?

    I have a hypothesis. A silicon based organism would produce silica as a byproduct of respiration. Silica is otherwise known as quartz in its crystalline form. Perhaps the crystals are really built by thousands of tiny silicon based organisms, each building on the remains of the others- similar to how coral polyps build a reef. The fantastic towering crystal spires could be the remains of these little builders, remains that shatter at nightfall only to be rebuilt the following day. Or perhaps it is something else entirely- after all, viruses leave us wondering if they are really alive. Perhaps aliens will do the same.

  16. Christopher Phoenix says:

    Scorpions are one of the most radiation resistant animals on Earth.

    To quote: “Scorpions are among the most resistant animals to the dangerous effects of radiations. In this respect, they go beyond vertebrates, mollusks, spiders, and most insects. It has been experimentally proved that some species are capable of resisting doses of radiation as high as 154,000 roentgens and then survive for at least one month.”

    I’d think that life on a moon exposed to high radiation levels would be radiation resistant as well. If scorpions can do it, why not aliens? Our pink fleshy bodies won’t fare well on such a world, however…

    I envied those Mountain Beetles sometimes. It was quite inconvenient to have a robot following me around carrying a lead umbrella on every naturalistic expedition into the wilds of Pandora.

  17. andy says:

    Sure every situation is a special case, but there are underlying general rules, on the basis of which you yourself used to criticise the Pandora setup in Avatar. However that particular rule (putting a satellite close to a gas giant automatically means increased geological activity) is not especially accurate as it is violated in our own solar system. Similarly your assertion that tidal locking means automatic hurricane force winds is also open to question. We can observe for example the Venusian atmosphere – admittedly not a tidally-locked planet, but one which exhibits a very slow rotation rate. The Venusian atmosphere exhibits superrotation in the upper atmosphere but has very low wind speeds at ground level, which is in qualitative agreement with the predictions from simulations you handwave away.

  18. Athena says:

    Christopher, I have seen that Disney film and I like it a lot. I agree that extraterrestrial life will be radically different. However, silicon is a very poor basis for complex life.

    Andy, I believe you have squeezed that particular lemon to dryness. Slow rotation is significantly different from no rotation. The point is (and we clearly agree about this) that 1) detailed planetary outcomes, including biology, are exquisitely sensitive to all input parameters although 2) broad conclusions are possible. Based on this, I can confidently predict that the Pandoran environment and life would not remotely resemble what is shown on Avatar.

  19. Christopher Phoenix says:

    Silicon does have drawbacks as a basis for complex life, compared with carbon. Silicon lacks the ability to form chemical bonds with the many diverse types of atoms, unlike carbon, which is not good for an organism’s metabolism. Long chain silanes decompose in water, and long chain silicones are still less stable than their carbon counterparts. A silicon based organism that breathed oxygen would exhale silicon dioxide, which is a solid at room temperature. Some people have pointed out that the animal’s respiratory system would fill with sand, but I think a silicon based organism would put the silica to work by building a structure around it.

    Silicon biochemistry might work better in alien environments with higher pressures and temperatures. Perhaps the fact that life on Earth is carbon based, although Earth’s crust is exceptionally silicon-rich and carbon-poor, is evidence that silicon biochemistry is poorly suited to Earth-type planets.

    Some organisms on Earth make use of biogenic silica, like diatoms that build a silicate skeletal structure. Extraterrestrial life forms might have silicon based structure molecules and carbon based proteins for metabolic purposes, so the organism can feed on abundant silica on Earth-like planets to build up the silicon based portion of its body. Similar to how the towering crystal spires fed on the drifting sand grains…

    I have a hypothesis on how the plants that feed on themselves survive. Some organisms on Earth, like the Portuguese Man o’ War, are made up of several specialized organisms that live in a symbiotic relationship. The zooids that make up the Man o’ War are so specialized and interconnected that they cannot survive without each other.

    I think the plant that fed on itself was really made up of several different organisms that clustered together in a colony. The red strings might be an algae-like organism that uses photosynthesis to produce food for the white tendrils, which eat the strings. You could say the white tendrils are farming the red strings. So we are not seeing a plant “that feeds on itself”. We are seeing a group of organisms that feed on photosynthetic organisms they keep within the center of the cluster. When the white tendrils feed, they appear to be eating their own body. It looks quite alarming, really!!

    All this makes me want to study exobiology, even though I already had my heart set on advanced propulsion research. At least I can use these ideas when world-building. I’ve got to fit that plant that feeds on itself in a SF story…

  20. Athena says:

    Your quotations sound like you read my Star Trek Biology book. There are additional problems with silicon: for one, in contrast to carbon, it’s not abundant anywhere in the universe. For another, its solvent would be fluorine-based — another rare element, whose soluble form is a poor solvent in terms of range.

    Symbiotic organisms are very common on Earth. As for exobiology, right now it is the study of terrestrial extremophiles, for lack of a second life sample — a major problem: it is essentially a discipline without content.

  21. Christopher Phoenix says:

    Actually, I have not read your Star Trek biology book yet. The quotations were from Wikipedia, which has an entire article devoted to alternative life chemistries. I’ll read your Star Trek biology book sometime- I can always use another good book on exobiology!!

    I never really had much time for books about the “science” of Star Trek, mostly because Star Trek is not very accurate in its portrayal of space travel and especially aliens. The later incarnations of Star Trek also tend to have far too many pseudoscientific explanations. We went from “The engines can’t take the strain, Captain!!” to “We need to modify the alignment parameters of the warp coils in order to extend the forward subspace field lobes to reduce the nominally effective mass of the blah blah blah….” The creators of Star Trek TNG admit that they just made up terms to sound cool. “Well, the warp engines work by passing plasma at a certain frequency through a substance called lithium cordonite,” or some nonsense like that. Don’t even get me started on the many occasions when humans interbreed with aliens.

    The abundance of the elements of life- carbon, hydrogen, oxygen, etc. is one of the major reasons for thinking that we are not the only forms of life the cosmos. The stars, planets, comets, etc. are all made of the same stuff as the planet Earth is. The elements we are made of are common throughout the universe. If the best molecules for life were made of some rare isotope of Bismuth, then we could make a convincing argument for humans being alone in the universe. I have little doubt that we will find that the universe is thriving with many forms of life.

    here might even be bizarre forms of life in our own solar system, such as warm blooded plants on Mars or Europan sea monsters. Freeman Dyson wrote a paper on this titled “Warm Blooded Plants and Freeze Dried Fish”.

    As Freeman Dyson notes, nature in the biological realm has a tendency to be fanciful. Nature has a tendency to be more imaginative then humans are. After all, no one in Europe ever imagined the duck billed platypus or bird of paradise before they were discovered by explorers. Another reason to get on the starship, I suppose.

    I have no desire to crawl through damp, dark caves to find some organism that resembles a ball of mucus, so I think I stick with physics. Unless someone figures out how to build a starship, we’ll never know what inhabits the exoplanets we are discovering today.

  22. Athena says:

    The two science of Star Trek books are really stealth science books — they use the series to discuss questions of biology and physics (colleges use them as auxiliary textbooks).

    Freeman Dyson has some odd ideas about biology. I believe he discussed the possibility of space trees a while ago, choosing to ignore the issues of both vacuum and lack of sufficient sunlight for photosynthesis.

  23. Christopher Phoenix says:

    Michio Kaku tried to follow such a “stealth science” tactic with “Physics of the Impossible”, but it ended up being a bit of a jumble. There are explanations of the four fundamental forces next to references to Star Trek and Back to the Future, a description of fusion right next to Death Stars, and so on. I found some useful information on recent work on teleportation and other fun details in “Physics of the Impossible”, but in the end I felt that I had learned far to little about physics that I didn’t already know and far to little about ray-guns.

    I’m a bit of a purist that way- I believe science should be taught from science textbooks. However, there is nothing wrong with getting students interested in real science through icons of science fiction. Then you get them to read the science book!!

    I’ll check out your science of Star Trek books sometime. It sounds like there is some good science in there- probably aimed at the Horta in the case of the difficulties of silicon as a basis of life chemistry (yes, I know all the Star Trek TOS episodes by heart!!).

    James Blish managed to capture the wonders of exobiology in the first novel of the “Cities In Flight” series, “They Shall Have Stars”. Set against the background of a decaying United States that has been eaten through and through by McCarthyism until it has become as intolerant and totalitarian as Soviet Russia, a group of astronauts teleoperate robots building a massive bridge on Jupiter, the true purpose of which is unknown to them. Along the way, a biologist discovers flying jellyfish drifting through the Jovian atmosphere, and one of the astronauts imagines a universe teeming with life- life on gas giants, under the crust of the icy moons of Jupiter, hibernating in comets and asteroids, even living plasmas dancing in the coronas of stars- lifeforms so diverse and unusual we may never recognize them as living beings.

    On the space trees- Mr. Dyson adressed the problem of providing the living greenhouses with sufficient sunlight for photosynthesis.

    One of the first steps a human colony would take to establish itself in the Kuiper Belt would be to surround its cometary habitat with an extended efflorescence of mirrors in space to collect sunlight. An array of mirrors sixty miles in diameter could collect a steady thousand megawatts of energy anywhere in the Kuiper Belt, out to three times the distance of Neptune from the Sun. That is enough energy to sustain a considerable population of plants, animals, and human beings with all modern conveniences. The mirrors would not have to be optically perfect. The material out of which to construct them, a few thousand tons of metal or plastic, would probably be available on any Kuiper Belt object. After a century of progress in biotechnology we would not need to manufacture the mirrors. We would teach our plants to grow them.

    As for vacuum- the general idea of warm-blooded plants is that they grow a protective “greenhouse” around themselves. I suppose we are to teach our plants to grow a spacesuit around themselves as well!!

  24. Athena says:

    The Dyson space technology is essentially fantasy in terms of feasibility; in an article that I don’t have time to trace right now, he actually did suggest “naked” trees in vacuum, which is absurd no matter how you parse it. As for science books, they are aimed at people who may never take a science course and are therefore unlikely to come near science textbooks. My opinion of Michio Kaku is that he borders pseudoscience sometimes, which is bad in a culture already teeming with it.

  25. Christopher Phoenix says:

    The “Dyson tree” doesn’t really seem to be a tree like the ones in my backyard, but a giant plant that grows a closed life support system nourished from the resources of a comet. Essentially, it is a living space colony that grows from a comet. Ordinary trees respirate, so they are permeable, incapable of surviving in the vacuum. Dyson’s trees would have to have a protective skin to shield it from the hazards of space. The inhabitants would breathe on oxygen the tree provides and exhale carbon dioxide that the tree uses.

    Of course we can’t deploy Dyson space trees today. Our genetic engineering can’t manipulate plants to such a degree that we can make them grow a living greenhouse, we don’t have spacecraft to travel to the comets we want to colonize, and we haven’t demonstrated a stable closed life support system yet. Dyson was discussing far future possibilities, ideas our descendants might carry out two hundred years in the future once space travel is routine.

    You seem to like using the word “fantasy” a lot. I don’t really apply the word “fantasy” to far-fetched technological speculation. I classify dragons, elves, and Harry Potter as fantasy elements, not Dyson Trees, starships, ray-guns, and terraforming.

    It definitely a good thing to present non-science majors with science books that provide them with a general knowledge of biology, physics, etc. Otherwise they will fall prey to pseudoscience.

    Right now, I am studying the science textbook “The Sciences, An Integrated Approach” by James Trefil and Robert M. Hazen. “The Sciences” goals is to increase scientific literacy amongst non-science majors, so they have some understanding and appreciation of the method and discoveries of science, and to be a broadening experience for science majors. Many science majors have little understanding of how the sciences fit together as a unified whole or what the other branches of science study. I intend on studying physics and hope to research advanced space propulsion someday, so this is just an introductory overview of the sciences for me.

    As for Michio Kaku- you are quite right that he borders on pseudoscience. He spends most of his time cultivating his ice-skating, science popularizing, tv-show hosting, news-caster interviewing, popular image, and is quite willing to shortchange scientific accuracy for sensationalism.

    His book is not nearly as alarming as his tv show “Sci Fi Science”, where he panders to a group of ultra-nerds dressed in an assortment of Star Wars, Star Trek, Aliens, Hellboy, and Ghostbusters costumes. Then, Michio goes on to present the technology of various SF shows as “the way it could be”, promising to fulfill the lightsaber-swinging, limb-hacking, Jedi fantasies of the nerd population. Along the way, he presents highly complex ideas like A.I., antimatter rockets, alien contact, space colonization, and terraforming in an simplistic and almost childish fashion. Worst of all, he presents some extremely speculative ideas like warp drives as something that can be built with a little ingenuity and help from Scotty. Science shows have fallen a long way in quality from the likes of Disney’s “Man in Space”.

    My mother described “Sci Fi Science” as “fruity” after seeing a short clip of it, and its easy to see her point. Rather than analyzing ideas seriously, Michio comes out on screen and says, “You too can hack the bad guys to bits with a lightsaber and blow up the Death Star in your starfighter!! The lightsaber is a plasma torch powered by nanobatteries, and the starfighter has antimatter engines. Now here’s my design!”

    Frankly, I could write a fanciful space opera along the lines of E.E Doc Smith’s “Triplanetary” and “Lensman” with far more scientific accuracy than Michio Kaku’s supposedly factual tv show.

  26. Athena says:

    There will be no routine space travel in two hundred years (if by space travel you mean beyond LEO). At most, there may be crewed expeditions to Mars — if we’re lucky and determined. Fantasy is defined as “The faculty or activity of imagining things that are impossible or improbable.” Terraforming, FTL, stable womrholes and a good deal more of SF falls into the fantasy category, with shadings from the impossible to the improbable.

  27. Christopher Phoenix says:

    There will be no routine space travel in two hundred years (if by space travel you mean beyond LEO). At most, there may be crewed expeditions to Mars — if we’re lucky and determined.

    Could you explain your reasons for thinking this? How can you know what our descendants will be up to in year 2210? Two hundred years ago, the only flying machine was a balloon. The Montgolfier brothers made their historic flight in 1783. 120 years later, the Wright brothers made the first sustained, controlled, powered, heavier than air flight in history on December 17, 1903. 63 years later, on July 20, 1969, the Apollo 11 rocket carried landed the first men on the moon. Nowadays, air travel is routine, and various companies are attempting to build commercial spacecraft.

    The U.S. space program could have done much better if Project Orion had not been cancelled for political reasons. Chemically powered rocket ships are extraordinarily inefficient and extremely uneconomic for space flight beyond LEO. Not so for nuclear pulse rockets, which can launch enormous payloads on interplanetary flights with a mass ratio well under ten.

    What confuses me about your statement are two things. You seem to be suggesting that even if we work very hard on space travel, we will be extraordinarily lucky to launch a Mars mission. Your tone is extremely certain, leaving no opening for alternative possibilities.

    I could understand your pessimistic attitude if you believed humans would never become motivated enough to develop spaceships to travel beyond Earth orbit. However, you seem to be blaming technology, not lack of will.

    I’ve noticed that you often offer enthusiastic support for a Mars mission while condemning any other possible destinations, like the Moon. Given that your research topic is cell biology and you wrote a book on the biology of Star Trek, I’d guess you are very interested in the possibility of extraterrestrial life forms. Mars is one of the possible locations we might find an extraterrestrial organism, such as an alien bacterium. I’m sure that most biologist would have a complete field day with such a second life sample.

    Some biologists don’t want humans tramping all over Mars because they are worried that they might negatively affect our chances of being sure the life we find their is native or hitched a ride with the astronauts. Everyone wants their pet project to become reality over everyone else’s, especially if those projects are mutually exclusive. Robert Zurbin wants to colonize Mars with the Mars Direct plan, and would fight an attempt to create an improved plasma rocket over launching Mars Direct, while a biologist might ridicule space settlements because they are more interested in Mars being a location for a few exobiologists rather than being divided up between groups of independent homesteaders who may or may not want to let scientists come look at the caves on their property.

    I am not taking sides here. I am interested in understanding how the often adversarial relationships between scientists in different fields can affect or even hinder progress. There is not enough dialogue between scientists in different fields on interdisciplinary topics like interstellar travel, and this leads to friction. Physicists and engineers focus on propulsion, but biologists, geologists, etc. haven’t the faintest idea what the rocket scientists are prattling on about, while the physicists never bother to go to the discussion on the ethics of space travel or how space travel affects the human body, etc.

    Conflicting viewpoints further widen the gap between scientists in different fields on the matter of space travel. The rocket engineers are ready to go conquer the red planet once they figure out how to get their rocket off the ground and keep it off the ground, while some biologists view their enthusiasm with dismay, fearing that their one chance to find a second life sample might be ruined by an astronaut who doesn’t take proper care when disposing of their space trash.

    My question here is whether you might have predict a future where only a few lone Mars missions ever become possible because, as a biologist, you wouldn’t want colonists tramping all over Mars claiming the place as their own property and quite possibly disrupting the search for extraterrestrial life?

    Being a biologist, you are likely to analyze the impact an invading group of space settlers would have on an alien environment, and the impact would likely be large, which would change your perspective of space settlements. Routine space travel would mean that humans claim other worlds as their own, forcing any indigenous life to move aside. No matter how high minded our ideals (the “prime directive”), we can’t help but alter the environments we settle in.

    The only way to protect the indigenous life on another planet would be to declare it the galactic equivalent of a national park, to be visited but not settled. Take nothing but photographs, and clean up your footprints when you leave. A few Mars missions would look for life but have limited impact compared to Zubrin’s plans to colonize Mars.

  28. Athena says:

    Christopher, I have addressed the issues you raise in older blog entries and in my book. If you search the tag “space exploration”, you will find it’s all there already. Many of your comments actually echo things that I said.

    Also, although discussions on space exploration are always interesting, it is really not recommended to write comments that are longer than the entries themselves.

  29. Walden2 says:

    Reporting Kepler 20e and 20f

    by John Hickman

    Monday, January 9, 2012

    How well do major American and British newspapers report space science news? The answer matters because it is print rather than broadcast news that continues to do the heavy lifting in communicating complex information. Even when the general audience is reading online about events involving space the source is typically a newspaper. Comparing the coverage in major American and British newspapers of the discovery of extrasolar planets Kepler 20e and 20f on December 21 offers interesting insights.

    What distinguished good from bad reporting of this story was that it both identified what was surprising about this discovery and provided context with background about detecting extrasolar planets and comparable previous discoveries. So rather than leave this particular news story suspended in isolation, it is integrated in a stream of news so that readers may construct a deeper understanding of the subject.

    Full article here:

  30. Athena says:

    The level of analysis does not come as a surprise — but seeing it all on one page is cause for depression.

  31. Walden2 says:

    Re-thinking an Alien World

    Jan. 13, 2012: Forty light years from Earth, a rocky world named “55 Cancri e” circles perilously close to a stellar inferno. Completing one orbit in only 18 hours, the alien planet is 26 times closer to its parent star than Mercury is to the Sun.

    If Earth were in the same position, the soil beneath our feet would heat up to about 3200 F. Researchers have long thought that 55 Cancri e must be a wasteland of parched rock.

    Now they’re thinking again. New observations by NASA’s Spitzer Space Telescope suggest that 55 Cancri e may be wetter and weirder than anyone imagined.

    Full article here:

  32. Walden2 says:

    Now we have an alien waterworld with a steamy atmosphere, orbiting a red dwarf sun in just 28 days:

  33. Walden2 says:

    Alien Life May Not Be So Alien – If It Exists At All

    by Jason Major on May 9, 2012

    Are we too hopeful in our hunt for extraterrestrial life? Regardless of exoplanet counts, super-Earths and Goldilocks zones, the probability of life elsewhere in the Universe is still a moot point — to date, we still only know of one instance of it. But even if life does exist somehow, somewhere besides Earth, would it really be all that alien?

    In a recent paper titled “Bit by Bit: the Darwinian Basis for Life”:

    Gerald Joyce, Professor of Molecular Biology and Biochemistry at the Scripps Research Institute in La Jolla, CA discusses the nature of “life as we know it” in regards to its fundamental chemical building blocks — DNA, RNA — and how its ability to pass on the memory of its construction separates true biology from mere chemistry.

    “Evolution is nothing more than chemistry plus history,” Joyce said during a Public Library of Science podcast.

    The amino acids that form DNA here on Earth — the only place in the Universe we know for certain that life can thrive — have proven to be highly successful (obviously). So what’s to say that life elsewhere wouldn’t be based on the same basic building blocks? And if it is, is it really a “new” life form?

    Full article here:

  34. Athena says:

    Yes, these have been my points regarding this topic for a long time now.

  35. Walden2 says:

    The Physics arXiv Blog

    December 18, 2012

    Three Habitable Zone Planets Discovered Around One Red Dwarf

    A red dwarf that is itself part of a triple star system, hosts three planets in its habitable zone, says astronomer

    Gliese 667 is a triple star system about 22 light years from Earth in the constellation of Scorpius. Two of these stars–Gliese 667 A and B–are Sun-like and orbit each other relatively closely.

    The third is much more interesting. Gliese 667C a red dwarf that is about a third of the mass of our Sun and only about 1 per cent as bright. It orbits the other two stars at a much greater distance: some 200 astronomical units or about 30 billion kilometres.

    Red dwarfs are particularly interesting for astronomers because their small mass makes it much easier to spot orbiting planets. What’s more, their low luminosity means that these stars’ habitable zones are much closer than for brighter stars.

    Since current planet spotting techniques favour closer planets, astronomers know they are much more likely to find planets in the habitable zone around red dwarfs. In fact, today’s news is a good example.

    Today, Philip Gregory at the University of British Columbia in Canada says that Gliese 667Chas three planets sitting squarely in the middle of its habitable zone.

    Gregory is a pioneer of new statistical techniques for evaluating the data from planet-hunting instruments. “The excitement generated by … many … exoplanetary discoveries has spurred a signi?cant e?ort to improve the statistical tools for analyzing data in this ?eld,” he says.

    So he’s used a new technique to re-examine data on Gliese 667C taken by the High Accuracy Radial velocity Planet Searcher, HARPS, attached the European Southern Observatory’s 3.6 metre telescope in Chile.

    He says this analysis indicates that the most likely number of planets around Gliese 667C is 6 with orbital periods of 7 days, 28 days, 31 days, 39 days, 53 days and 91 days. Only two of these were already known.

    However, the most interesting news is that the 28, 31 and 39 day-planets are all smack bang in the middle of the habitable zone, he says.

    These planets are all larger than Earth but the 39 day period planet (planet e) is only just over twice Earth’s mass. That makes it “the lowest mass planet in the habitable zone detected to date,” says Gregory.

    That’s exciting news which will make Gliese 667C the target of significant interest in the near future from astrobiologists wanting to know more about these potentially Earth-like places. And with three to examine around a single star, they will be spoilt for choice.

    Ref: Evidence for Multiple Planets in the Habitable Zone of Gliese 667C: A Bayesian Re-analysis of the HARPS data

  36. Walden2 says:

    100 billion exoworlds in the Milky Way galaxy alone?

  37. Walden2 says:

    What can celebrated Polish author Stanislaw Lem teach scientists about alien life?

    Annalee Newitz

    Jan 29, 2013 4:30 PM

    What would it really be like to encounter alien life? This is the subject of a newly-emerging academic field called astrobiology, or the study of life beyond Earth. Now, in a new book called Alien Life Imagined: Communicating the Science and Culture of Astrobiology, astrobiological researcher Mark Brake combines stories from both science fiction and the world of science to explore how our ideas about alien life have changed over time. In this excerpt from his book, he deals with how astrobiology has changed in an age when we are actually traveling to other planets.

    Full article here:

  38. Athena says:

    Astrobiology is not new any more but unfortunately it remains a discipline without a core. The book itself is unlikely to be widely read — it’s clocks in at $44 (!). And although Solaris is a very interesting exercise in creating a very different alien, the simulacrum portion is daft.

  39. Athena says:

    By the way, Mark Brake claimed he had a PhD (which he did not) and fell out with all of his partners in the Astrobio venture; the university finally and quietly “made him redundant”. Between the transhumorists and people like this, io9 is batting poorly on the credibility index.

  40. Walden2 says:

    The Habitable Zones have shifted – from science’s current perspective at least:

  41. Athena says:

    1. No second life sample, so it’s all still theory (and shaky theory at that).
    2. For the Glieselings in particular, it shouldn’t be called Goldilocks, but will o’ the wisp.