24 Exoplanets Would Be Better for Supporting Life Than Our Earth

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Washington State University researchers have identified 24 top contenders for super habitable exoplanets that would be better at supporting life than the Earth. The exoplanets are all over 100 light-years away. There is now a database of 4500 exoplanets from the ongoing surveys of other stars.

Superhabitable exoplanets have the following features:
* are in the habitable zone of their star. This orbit means that they would have a surface temperature for liquid water.
* Older planets would have more time for life to develop. It took 4 billion years for life to develop on Earth. Superhabitable planets are 5 to 8 billion years old.
* A planet that is 10% larger than the Earth should have more habitable land. One that is about 1.5 times Earth’s mass would be expected to retain its interior heating through radioactive decay longer and would also have a stronger gravity to retain an atmosphere over a longer time period.
* they looked at planets around G type stars that are like our sun but also K dwarf stars. K dwarf stars could keep planets habitable for 20 to 70 billion years because the star burns at a cooler and more sustainable way.

Our telescopes are not good enough to confirm some of the features of these exoplanets. We cannot identify how much land they have. However, new generations of more powerful telescopes will enable better observations. Even the planetary mass estimates are very crude. The 24 candidates were planets that are estimated to have two Earth masses or less. However, the mass estimates are based upon the estimate of radius. The radius are less than 1.6 times the Earth radius.

We still have a lot to learn. We have only just started having telescopes that can identify exoplanets indirectly based upon the gravitational wobbling of the star. An interesting possibility is that a habitable planet might be around 5% of stars and super habitable planets could be around 0.5 to 1.0% of stars.

Astrobiology – In Search for a Planet Better than Earth: Top Contenders for a Superhabitable World

SOURCES- Washington State University, Astrobiology
Written By Brian Wang, Nextbigfuture.com

59 thoughts on “24 Exoplanets Would Be Better for Supporting Life Than Our Earth”

  3. Good point. However, it's not just birth control that is driving down birth rates. Affluence, economic development, women's rights, and the cost of child rearing are all combining to push down births per woman. Which raises the question – we will go extinct in the next several thousand years? In most western countries birth rates are below replacement level. Once the rest of world reaches the same level of economic development we can expect all countries will experience below replacement birth rates. I suppose it may come down to whether or not we can radically extend human life spans.

    Chris68

  5. Oh yeah. Planets with tectonic plates are going to be a dime a dozen.

    There are dozens of reasons (or more) why that list of 8 things in Table 2 could be astronomically unlikely, or even impossible.

    Yes, I know, nothing is impossible. But if you drop a glass of milk and it shatters on the floor, don't hold your hand out hoping it will all come back together, refill itself, and leap back into your hand. Even though it is not impossible, you will likely have to wait far longer than any current model predicts the universe will exist.

  6. Good news: we already have birth control, and the result is the populations are forecast to shrink, not grow; indeed already have started shrinking in some nations.

    No world dictatorship required.

  8. There is no point to trying to inhabit these other worlds if we can't control our population growth here. A birth control pill and a population council is a lot less expensive than overpopulating everywhere else.

  9. Most interesting is the claim that better homes for animals, etc. are on planets 5C warmer than Earth. Note that during most of the time that complex life flourished on Earth temperatures were MUCH warmer than today. No need for panic over AGW.
    http://scotese.com/climate.htm

    Disclamer: I don't like hot weather personally. Not going to super habitable planets!

  10. Do I have good news for you! 50 years ago, O'Neill asked whether the surface of a planet (Earth, as the example) was the right place to live, as a tech civilization. Once the question is asked, the answer is clear. NO! so we don't need no stinkin' planets anyway.

  11. Cheer up! You might find a hundred rogue planets between the stars, for every stellar system with a clutch tightly held. Clever thinking might make them hospitable, rather than just a formidable challenge.

  12. Your sun will be too energetic in 800 million Earth years for liquid water to exist at the surface, without some solar shade additions. You could change the orbit as an alternate approach. Don’t panic yet—there is still time!

  13. On a serious note, if there really are millions of Earthlike planets around, maybe billions, but no other technologically advanced life we can detect, maybe the problem lies deeper.

  15. Within the next 100 years, almost with unimaginably improbable odds of NOT being able to do so, humankind will be able to rework the genome of any plant and animal with the flexibility that today we abstractly re-imagine billion-transistor chips.  As graduate school projects.  

    Reëngineering the gene (set) to defy ageing, to defy mental decline, to defy the wear-and-tear of the ambient elements, and yes, even being pierced whole by gazillions of cosmic ray particles in deep space, that too will be within reach of the The Genetic Engineers.  

    Humankind will last the 25,000 'apparent' years. That is clear. Many not 25 million, but certainly a LOT over a thousand.  

    If however one goes Asimov and continues to abstract… it is even more clear that our homeworld's interstellar prospectors will be AI entities at least if not likely more sophisticated than a handful of IQ 150 specialists. Moreover, replication and duplication, which is a proxy for error-correction-for-cosmic-rays … is also much easier. Being able to be a 'being' without losing one's memory, ever … that will be the ticket.

    To the stars.
    ⋅-=≡ GoatGuy ✓ ≡=-⋅

  18. It's an additional force, not a substitute.

    That's why measurements of the gravitational constant, all performed on Earth, get the wrong answer.
    When we try to use that figure to calculate the gravity of astronomical objects, we end up thinking there must be a lot of unseen "dark matter" that is throwing our calculations out.

  19. Given that Earth has large, multicellular, life forms with lifespans push to 10 000 years*, this doesn't strike me as impossible.

    One can easily imagine a species originating on a planet where the orbit has millennia of deep winter between brief summers that develops suitable hibernation abilities. Where a 0.1% C space ship gives them interstellar travel quite easily.

    *Some plants. Eg. Huon pines

  20. Actually, assuming the NASA definition of life, which I think is basically correct, we can probably say a lot about life elsewhere. Chemistry dictates a lot. So does the requirements of complexity (eg multicellularity). We also know from earth that evolutionary solutions to ecological niches converge on common forms. I used to think life could be totally unpredictable but as a biologist that has changed.

  21. We have the potential to create a stable equilibrium with Nature. The aboriginals of Australia engineered the ecological landscape for tens of thousands years to their benefit but in a sustainable way. The main problem we face is the exclusion of such considerations from our economic system.

  23. The trip will be in as nice a place as the destination. If not nicer. Why assume there are planets there at all, just find stars that show spectra indicating heavy elements and go. Or, stay where you are. I am assuming you do not actually want to live on a planet.

  24. There is a good side to humans, love, which is the genetically evolved response to our *ritually* evolved repressive System(s), coevolution at the highest level. We will keep the love after the System is destroyed. I certainly believe in the creative process you describe, indeed wanting to both preserve what is here, there, but also give *it* more expansion options than on one planet. But I do want to return Earth to as near as possible to *as If* we had not existed (I know, the ice age is different), just as a general experimental or observational principle. Then, let it do as it will, except perhaps be in the path of a big 'roid. Surely we can spare one tiny planet from our control? The 'atmosphere encased islands' will be collectively thousands or more times the Earth's territory, just in this Solar System. Not, ahem, to mention Mars.

  25. besides – the universe is fundamentally self-renewing (with destruction as part of the cycle)- how do you know that Earth was not intended to be an intelligent species 'recycler/ incubator'? It might have been the intention to incubate an ape-descended race – have it clearcut all and get it away and out into space – so that the next 1/2-billion years could be spent spawning the aardvark-descended intelligent species — get them into space — then bird, crayfish, dolphin, fern plant, stink beetle, etc. Stasis and conservation is the most universally-un-natural of all behaviours – whether single-celled or space-faring.

  26. Your anthropomorphic-hyper-cynicism aside (of course, completely warranted – i feel the same) – I will never accept humanity as a 'spectator species'; living a cultural existence in a glorified space Winnebago as some kind of civilization of prime-directive-wienies. Humanity is hard-wired to be curious, meddlesome, interactive, hands-on, tinkerish, etc., – which of course, labels us as more animal than an intelligent 'exploratory' species — which can hopefully, eventually lead to less destructive interventions. That being said 99% of all species globally (and many trillion times that closer to 100% – galaxy wide) have gone extinct and many trillions times more in total of quantity of previous species that have ever existed will at some point 'exist' going forward (i'm not sure how we would determine 'peak' complexity as we head towards Universe Cold Death) – so the idea of taking a 'conservation snapshot' of earth's current systems (in trying to maintain a large part of a re-wilded earth) seem absurdly quaint (of course, no reason to destroy haphazardly) – similar to saving every NY Times front cover in your house. There would be more 'earth's history curation' value in creating an artificial asteroid belt of various size 'atmosphere incased islands', each with a fragment of earth's various eco-systems over the centuries all encased and customized to have enough internal coherence and artificial 'boundary' condition species that it can maintain its 'ideal' eco-health.

  27. Of course, it is interesting to speculate on the prospect of getting there. I think it makes no sense to have two journeys to each planet: one to explore and one to bring people. It makes more sense to me to have a vehicle that is small and powerful that can print DNA (better to print it than to try to protect it from damage over hundreds of years) and possibly cells (bring frozen cells with no DNA otherwise), grow humans in artificial wombs. But it would start with small ships with a few nanites and use the materials at the destination to build, more nanites, the artificial wombs and the life-sized AI robots, shelters and necessary infrastructure to care for them and any other animals or plants chosen to colonize.
    Send out millions of these seed craft, most of which have no destination already chosen. Perhaps they could relay messages of what they have found and colonies they have seeded.
    After maybe 50 years on the planet and all the infrastructure of the planet has been built, perhaps hundreds or thousands of cloned ships like the first can be launched. The whole galaxy could be colonized eventually.
    Dragging actual people from Earth hundreds of light years just does not make much sense. Frozen people 50 light years with ships that can go at least 1/4 the speed of light maybe. High investment, low return, in my opinion. Yes. You get everyone's gee-wiz upon waking up on a new world, but how long does that last?
    And starting with cells and DNA has large advantages.

  29. It should have been something like: "It took almost 4 billion years for *complex* life to develop on Earth."
    Complex being multi-celled, specialized organs.
    Even that is a bit off, but much closer.

  31. So the answer to the Fermi paradox is that no aliens come to Earth, because it sucks.

    Too small, too young, the star has too short a habitable life span, not enough atmosphere: you could still get radiation burns from the star standing on the planet's surface! The native inhabitants would literally travel around with radiation shields on their upper bodies, and radiation filters over their electromagnetic radiation detecting organs. That's absurd.

  33. I'm afraid we are doing something like what you describe in a negative way, for about 70,000 years. "biodiversity" can be as simple as more kinds of stuff. Don't kill it off! Then, as the Earth is not a needed resource for such a competent species, make it a Nature preserve, if for no other reason than to laugh at how primitive it is.

  36. You've both been watching Isaac Arthur, haven't you?
    Phosphowous may be necessawy fow wife as we know it, but othew fowms of wife may yet exist

  37. [part 2] which sez "Planetary magnetic fields shield planets and life on the planet from harmful cosmic radiation. If a late, violent and giant impact is
    necessary for a planetary magnetic field then such an impact may be necessary for life."
    And Saturn seems to be so windy that a core does not even form inside, I think!

  38. Of course, we may be engaging in a bit of hyper-sentimentality, since it is very likely that humanity itself will start to engineer better organisms, better animals, richer and denser ecosystems, types of ecology of such a varied nature that any world could support them, and ultimately the means to create a level of complexity (the ultimate test and judgment of biodiversity) way beyond what simple 'Nature' herself could ever hope to accomplish. Further, it is entirely likely that older and more sophisticated exo-cultures have done just that with their 'home world'. Perhaps, even before they became a space-faring entity. A world that is most likely to achieve the base conditions for 'intelligent life escape velocity' might be all that's required to spawn a 'complexity cascade' – whether such a base condition could achieve its intelligent inhabitants a billion years sooner could be of interest and may be part of the Fermi.

  39. Depends on whether "develop" means "start" or "think". And the short time from molten to start means *we* probably came from Mars, I think.

  42. Maybe, but since so many of the Jovians have powerful magnetic fields, and don't fall into that Moon-makes-magnetism dynamo theory, there clearly are other means.

  43. So, MB, think long.  FAR longer than a human life span. (i.e. we have the lifetime of fleas compared to elephants, say…)

    On a 25,000 to 100,000 year window of 'interest', one could, without resorting to near-science-fiction near-lightspeed transport, one could traverse the stars in the local 100 LY radius sphere.  ⁴⁄₃πR³ … = 4.2 million cubic light years of space.  Turns out there are know to be at least 1,800 F, G and K stars within that volume. More likely at the K and M (especially) side, but they are usually also encumbered by heavy x-ray flare activity.  Best is between F (somewhat hotter-and-yellower) and K (somewhat more orange and cooler) than our G star. 

    1800 candidates to go visit. Maybe all of them can be well imaged in the next 100 years by fabulous space-based kilometer-scale interferometer objective 'telescopes' (bad word, but they clearly are kind-of-optical instruments).  We determine there are 5% having 'interesting planets' in well regarded orbits. 

    90 stars to VISIT. Up to 10,000 LY to 'get there';  maybe speed-of-light high-spectral purity laser back-communication to relay what's found. Images. Spectrography. Hêll, who knows, even atmospheric sampling!

    Within that 25,000 years, we learn of a few percent of those, maybe 10 in whole, which actually have abundant conditions conducive to supporting life. And that DO.

    Whoopee!

    Just takes 25,000 years.
    ⋅
    -⋅-⋅ Just saying, ⋅-⋅-⋅
    ⋅-=≡ GoatGuy ✓ ≡=-⋅

  44. Large moons around Jupiter size planets could have life due to tidal heating.

    Super earths further out from their sun could also have life because their thicker atmosphere could retain more heat and offer more protection from flares. They could also provide more heat from the interior.

  45. Twoo, but it turns out that phosphorus accumulates by 'concentration' in sea water. Interstellar phosphorus concentrations are well below Sol's likely nebula levels; we were blessed with the stuff. But as many-a-land animal-and-plant 'knows', there is plenty of life possibilities at phosphorus levels FAR below the planetary crustal mean.

    So… not so much of a problem, I think.

  47. Yes indeed. A movable shell of great expansive possibilities, each one and in numbers. Unless we move into tiny computers to go fast!

  50. I think a lot of people are stuck on that. The reality is that we will become an organism that has a shell. A shell of technology.

  51. You should ask yourself: Is the surface of a planet the right place for an expanding technological civilization? A lot depends on the correct answer.

  52. I thought that the magnet was caused by the Moon creating collision happening to be in such a way that the outer part of the Earth slowed down, with the core continuing faster. Lunar tides keep slowing the outer layer down, so the core never slows enuf to catch it. The difference leads to magnetic dynamo at the layer, and the protective field. Seems kind of rare?

  53. Such a planet could be great for life…aquatic life. Also high air pressure allows flight to be much easier for creatures. Large mats of algae could form floating islands, as could pumice, or odd waxes from secretions of creatures.
    The comment system is going loony. I was signed in: Mindbreaker

  54. They are assuming Earth-like life. But rationally, it seems to me there is nothing more Earth-like than Earth.
    If you are going to say life in general in the Universe, we simply have no way to say what is possible, common or favored.

    If we had solid information on the atmospheric compositions, the land and seas, temperature range and stability, distributions of elements (especially those needed and those that are toxic), planetary rotation, effectiveness of ozone layer/magnetosphere, we could say if Earth life could survive there without advanced technology. But we could not say much more than that.

  55. Incredible!!! So if there are 200 billion stars in the milky way, we're talking something in the range of 100 million habitable planets just in our galaxy. Even more reason for Elon to do his thing. I only wish I was born 100 years later. It is what it is. I'll be satisfied with Mars. Go SpaceX!!!!

  56. I don't believe this. I think many of these planets are waterworlds, with oceans up to a 1,000 kilometers deep and thick atmosphere up to a 100 atmospheres of pressure.

  57. "It took 4 billion years for life to develop on Earth."
    not really. to my knowledge, life appeared on Earth pretty much as soon as it was able, some 4 billion years ago. given that the Earth is about 4.5 billion years old, this statement would imply that there was no life on Earth before 500 MYA, which is patently false.

  59. A planet being in the habitable zone is not the only thing required for life.
    Life also needs Phosphorus and Phosphorus is relatively rare in the universe, the rarest of the six elements required for life as we know it.

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