Thrilling Discovery of Seven Earth-Sized Planets Orbiting Nearby Star (theguardian.com)

At a press conference on Wednesday, NASA scientists announced that they have spotted seven Earth-sized planets orbiting closely around a small, ultra-cool star. The star is 39 light years away. From a report on The Guardian: It is the first time that so many Earth-sized planets have been found in orbit around the same star, an unexpected haul that suggests the Milky Way may be teeming with worlds that, in size and firmness underfoot at least, resemble our own rocky home. The planets closely circle a dwarf star named Trappist-1, which at 39 light years away makes the system a prime candidate to search for signs of life. Only marginally larger than Jupiter, the star shines with a feeble light about 2,000 times fainter than our sun. "The star is so small and cold that the seven planets are temperate, which means that they could have some liquid water and maybe life, by extension, on the surface," said Michael Gillon, an astrophysicist at the University of Liege in Belgium. [...] While the planets have Earth-like dimensions, their sizes ranging from 25 percent smaller to 10 percent larger, they could not be more different in other features. Most striking is how compact the planet's orbits are. Mercury, the innermost planet in the solar system, is six times farther from the sun than the outermost seventh planet is from Trappist-1.

Comments

I am not saying it was aliens...

[sinij]

I am not saying it was aliens... but these were alien worlds.

Sterile and shattered.

[Anonymous Coward]

The blast of sterilizing radiation at that distance, combined with being tidally locked and probably wracked with catastrophic earthquakes at that distance would make life on these planets an unlikely impossibility.

Re:Sterile and shattered.

[MightyMartian]

I think that greatly depends. Without a strong magnetic field, the Earth would look a lot like Mars, with much of its ancient primordial atmosphere blown away. I can imagine if one or more of those planets do indeed have a strong magnetic field, then I don't see how it is improbable that they could not harbor life. At the moment, we can't even declare with a high degree of assurance that Mars does not host life.

Re:Sterile and shattered.

[Gorobei]

Bacteria living underground/underwater don't care much about radiation or earthquakes. Of course, it's bacteria, so we aren't going to be swapping porn or MP3s with them anytime soon.

Re:Sterile and shattered.

[bobbied]

But you can bet there will be a bunch of space cadets saying we should mount a mission to explore these "earth like" planets in our intergalactic back yard.. Never mind that it will take tens of thousands of years with current technology to actually get there and back at the speeds we can manage right now...

Re:Sterile and shattered.

[Anonymous Coward]

This is a red M class Dwarf star. The lack of radiation is the more immediate concern rather the excess of it. Red M class dwarf stars emit most of their radiation as infra-red, and barely emit any ultraviolet. If ultraviolet radiation is indeed a requirement for life, then this will be a problem. Total sterilization is unlikely, since the amount of energy hitting the planets will likely be similar to what the Earth is already getting.

Also, wrt tidal locking, the main concern would be that one side of the surface will be boiling while the other side will be freezing (one side gets all the sun, the other side gets none), which IS a concern wrt. life. Earthquakes are not a direct effect of tidal lock. That would be geological activity.

Of course, all of this is conjecture. We need to study these kinds of planets a bit more to know for sure. Hence, their importance.

Re:Sterile and shattered.

[MightyMartian]

I remember playing a SciFi tabletop roleplaying game years ago that had a world generation system, and that one suggested that a tidally-locked world could have a "habitable zone" along the terminator, where temperatures were relatively moderate. I don't know how reasonable that is, since I would imagine that having half the planet's atmosphere at one temperature extreme and the other half at another could lead to some pretty extraordinary heat exchange, in the form of pretty brutal storms.

Re:Sterile and shattered.

[SuricouRaven]

Mars first. No need to run before you can crawl.

Though so far our record is to crawl to the moon, feel proud, then crawl back down our hole and declare the rest of the universe isn't that good anyway.

Re:Sterile and shattered.

[bobbied]

And what makes you think the rest of the universe is 1. good and 2. reachable?

Our most efficient drive system to date (in terms of how much acceleration you get for the amount of propellant used) are plasma/ion engines. They run on electrical power. If you do some rough calculations on the size and weight of a manned space craft with provisions enough to make even a short (say 12 light years or so) trip, the power requirements of the engines alone will exceed the total generation capacity of the world's electrical grid....

Re:Sterile and shattered.

[number6x]

The blast of sterilizing radiation at that distance, combined with being tidally locked and probably wracked with catastrophic earthquakes at that distance would make life on these planets an unlikely impossibility.

The sun is a red dwarf and is 0.05% as bright as our sun. It has 8% of the mass of our sun and is 10% of the radius of our sun. It is much smaller, lighter and cooler. Not very much larger than Jupiter. The planets are likely to be tidally locked. Jupiter's Galilean moons are tidally locked to Jupiter, but they are not blasted by radiation. The study showed gravitational synchronization in their orbits, so that could cause earthquakes.

If the star were our sun the planets would be blasted wastelands tidally locked to their sun. I think the exciting point is that this system is 'only' 40 light years away, so we should be able to study it over the next few decades and learn much more. The planets are transiting their sun, as seen from earth, so we should be able to detect gas within their atmospheres through spectroscopy. Over the next few decades advanced space telescopes should help us gain a great deal of information on this system.

Could there be life> maybe. There is a whole lot to learn and a great many engineering challenges to solve to let us learn. For me that is more exciting than maybe a small chance of life.

Re:Sterile and shattered.

[Immerman]

You're missing a rather important detail there that makes your claim essentially meaningless: time.

We've already launched a few probes that, had we chosen to aim them correctly, would eventually have reached a nearby star system. Sure, Voyager 1 would take ~17,900 years to cross the 4.2ly to Proxima Centauri, but it would so with paltry energy consumption and far less efficient propulsion systems.

Granted, that's probably too slow to interest anyone in making the trip, and the energy requirements increase dramatically as you travel faster, but that's why most near-term plausible speculation assumes (non-FTL) travel between stars would be in generation ships - it's a much easier problem to solve if you're willing to take a century or three to make the trip.

Of course that's a long time to keep a relatively small closed ecosystem healthy, so we'd probably want to wait until we had a century or two of experience building and maintaining long-term viable space stations before we even attempted it.

Also, you talk about the "total generation capacity of the world's electrical grid" as though it's some sort of meaningful indicator about future energy producing capability. In fact though, that's not even a tiny fraction of the energy we're already adding to the Earth today - the CO2 released into the atmosphere by burning fossil fuels captures about a million times more energy than was generated by the power plant.

Re:Sterile and shattered.

[MightyMartian]

One thing we know for certain about at least some of the Galilean moons that due to the gravitational craziness of Jupiter and the big moons, these bodies are pretty damned dynamic. Io is probably the most geologically active body in the solar system, and while Europa's icy crust is fairly dull, a liquid ocean underneath suggests that it is very geologically active as well. I wonder with planets being that much closer to the star, and that much closer to each other, that the relatively low energy output of their star would be made up for by similar gravitational interplay, and being that much closer even though the star is very dim, there's still a lot of energy available. I don't think there's any kind of real proof forthcoming, but there seems a general view in scientific circles that where you have liquid water, organic material and energy, life may be an inevitability.

Re:Sterile and shattered.

[saloomy]

I don't see why we would have to send a manned probe. Men require life support, space to live, extreme limits in G forces, extreme radiation shielding, protection from the elements (think running into debris at relativistic speeds), and probably a means to establish a colony on the other side, all of which assumes there is something suitable on the other side to establish a colony on.

Instead we could send a robotic explore there in say 80 years (spending half the time speeding up to light-speed, half the time decelerating back down), with sufficient instrumentation and propultion to navigate the remote star system. It would essentially spend the majority of its time in hibernation except for the engines. I remember watching a Carl Sagan documentary where he postulated that going fast enough, you could pick up fuel on the way. Going fast enough, you run across enough lose hydrogen in deep space to build a small pressure on the front of the craft. IF you could set up some sort of collector and compressor on board, you could then use the collected hydrogen as propellant sending out the back end. This would reduce the size of the craft, so all you would need is a high-output nuclear power generator to drive the ions out for 80+ years. Once it gets there, take a bunch of pics, collect data from small daughter probes launched onto suitable surfaces, and relay that information back to earth, 40 years after arrival. Thats what a mission to one of these solar systems will look like. Were talking a 500 year span of missions by the time we can send humans.

Re:Sterile and shattered.

[bobbied]

I'm talking about the *current* state of technology... If we do this *now* what could we reasonably expect and make the trip in less than 50 years using our most efficient solution currently in development (or flying).

There is a theory that until we get round trip times down to 50 years or less, it's not worth trying.. Why? Because it is expected that advancing technology will likely make future trips possible at a faster speed and missions using that extra speed will likely pass the previous mission in route and return BEFORE the slower mission with the head start.

Apart from the ethical and moral problems that generation ships present, we are nowhere near being able to engineer a self sustaining ecosystem. We haven't even yet demonstrated enough proficiency in doing this on the ground, much less in space. "Generational ships" are nothing more than a pipe dream, and will never happen. The moral and ethical questions alone should make that obvious. How can you condemn future generations to carry a mission they didn't have any say about, may not wish to participate in, and didn't accept the risks associated with the mission? How will such ships be governed? Is it moral to send such missions out with zero means of return and nearly zero chance of success?

Your fossil fuel statements are pretty much hysteria... The fraction of CO2 in our atmosphere from burning fossil fuels is nearly insignificant. In fact, I'm told most plant growth is CO2 limited... (Meaning it is the lack of CO2 that limits their growth). Plant growth is what most fossil fuels came from, during a time when CO2 was a LOT more plentiful than it is now. In short, I think you are falling for a bit of hype, then inventing some wild theory about CO2 being responsible for such large amounts of retained heat... The fraction of CO2 that is man sourced in the atmosphere, pales in comparison to the *natural* amount that is necessary to keep plants growing.

Re:Sterile and shattered.

[avgjoe62]

I think we've got plenty of porn to share with them right now (and don't you just wonder where they got those tiny cigarettes they light up afterwards?)

Re:Sterile and shattered.

[harperska]

Jupiter's Galilean moons are tidally locked to Jupiter, but they are not blasted by radiation.

Actually, they are. And it is a major source of headaches for probes we have sent to Jupiter. Jupiter has a very strong magnetosphere, which has given rise to radiation belts much like Earth's Van Allen belts only much more so. And at least the inner Galilean moons are right in the middle of these radiation belts.

Re:Sterile and shattered.

[currently_awake]

An unmanned probe would use much less power, over a longer time, to reach there. I think we should send the probes first before we spend money on sending organic life.

Re:Sterile and shattered.

[JoeMerchant]

life on these planets an unlikely impossibility.

I think your unintentional double negative is actually forming a reasonable conclusion: chaos, upheaval, relative stability due to tidal locking, all of these may very well combine to create an environment in which self-replicating processes thrive and evolve. The garden of Eden? Definitely not, but the creatures that evolve there might have equally horrific visions of what living in a bath of aggressive bipolar solvent would do to them.

Re:Sterile and shattered.

[allcoolnameswheretak]

Seven Earth sized planets orbiting at such close proximity to a sun that is just marginally larger than Jupiter, so say the sun has three-times Earth gravity. Isn't that a highly unstable system? Every planet orbit in that system is being strongly influenced by the orbits of the six other planets.

Re:Sterile and shattered.

[MillionthMonkey]

One thing you're forgetting is that these stars have very low gravity, so when they throw flares they get a lot further out into space than they do on the sun. Typically the incident radiation will be low for the reasons you described, but when a planet orbits through a flare it gets zapped really hard. Meanwhile, orbiting the sun, we are so unaffected by flares that when we saw one, we thought it was the Russians jamming our radar.

People who get excited about aliens living on planets orbiting dwarf stars are kidding themselves. These stars are a dime a dozen and make up more than 90% of all stars, their light is more strongly affected by planetary transits, and they tend not to gobble up their innermost planets when forming. It's no wonder we find exoplanets around them all the time. But there is nobody interesting living on any of them. You can really only trust type F and G stars with life. Larger stars explode so fast their planets haven't even had time to solidify, and smaller stars have to be hugged so closely that the planet is affected by the star's fickle weather patterns.

Re:Sterile and shattered.

[Anonymous Coward]

> How can you condemn future generations to carry a mission they didn't have any say about, may not wish to participate in, and didn't accept the risks associated with the mission?

Easily. This is not some kind of age-old philosophical question without an answer. It's irrelevant. None of us had a choice in being brought into the world whatsoever, no-one who emigrated gave their unborn children a chance to remain in the old country, and no-one chose to be brought into a world where bad stuff happens or some artist you don't like is famous.

What we do not get to do, morally, is bind those future generations into accepting the situation by ensuring that they have no residual rights (as for example, you were granted by virtue of being a citizen) and no outlet of action (i.e. you can rig the game by constraining them by fact - for example ensuring that the ship cannot be turned around without destructing).

Re:Sterile and shattered.

[Ken McE]

>The blast of sterilizing radiation at that distance, combined with being tidally locked >and probably wracked with catastrophic earthquakes at that distance would make >life on these planets an unlikely impossibility. ____ For the X-ray blasts you need a tendril or a root or something that goes deep enough down into the dirt/water to survive and regrow. UV tolerance is easy if you can accept the loss of your photosynthesizing bits and regrow them from the opaque parts. Most living things are really not troubled by earthquakes (Trappist quakes?) We have trouble with them because we build things that are rigid. The main effect from being tidally locked is that you don't need to move your leaves around to follow the sun, you just grow and aim them once and leave them. You might even get concentric rings of plants with different brightness requirements growing all the way along the sunny edge. I don't know if life would be easy, but let's not give up yet.

Re:Sterile and shattered.

[Immerman]

Let's dial that back a little: *relativistic* space travel might be *difficult* near stars. That sucks for anyone dreaming of vacationing among the stars, but isn't really an issue for anyone patient enough to embark on a multi-generational voyage, or just slow down enough for sacrificial scout-ships to clear the way through the Oort cloud.

Re:Sterile and shattered.

[Immerman]

Agreed, robotic probes make a lot more sense, at least until such time as we find something worth visiting in person (or something worth getting away from here)

Re:Sterile and shattered.

[Immerman]

Actually the amount of CO2 we release is easily calculated from the amount of fuel we burn. And measurements consistently show the amount of CO2 in the atmosphere increasing more slowly than we're adding it - it doesn't take a genius to realize that if a swimming pool is filling more slowly than you're adding water, then it wouldn't be filling at all without your help.

Meanwhile the atmosphere now contains about 30% more CO2 now than it did a century ago, mostly because of fossil fuel emissions. 30% may not sound like much, but it tips of the scales in an energy flow that completely dwarfs all human activity - translating to more excess solar heat being retained every day than humanity uses electricity in a century.

As for plants being CO2 limited - so what? Obviously they're not taking up the slack, or CO2 levels wouldn't be increasing. And as a matter of fact it appears that global biomass is actually decreasing, rather than increasing to keep pace with the increasing CO2. Though admittedly that part probably has more to do with more direct pollution and environmental destruction for now. Perhaps if we were otherwise responsible stewards of the planet, it could neutralize our fossil CO2 emissions, but we're pretty much attacking it on all fronts instead.

Re:Sterile and shattered.

[Immerman]

Though there is a point to be made that any early generational ship is unlikely to be able to turn around without first stopping at the target star to refuel. After all, turning around takes far more that 2x as much fuel as stopping, even before you include the additional fuel you'd need to stop once you got back to Earth (and the additional fuel needed to carry that fuel, and the additional ...). You could conceivably carry that much extra fuel, but you'd probably be better off dedicating all that payload to stuff that would be useful at your destination.

Basically any generation ship built in the forseeable future will be a one-way trip for those embarking. The generation that reaches the destination has the option of refueling and heading back, but they're unlikely to survive to see Earth, and meanwhile will be committing additional generations to be born on ship.

But then nobody asked me if I wanted to be born into a world being actively destroyed on a barely imaginable scale, or in a country that has apparently been convinced that waste and stupidity are aspirations to strive for. But, just like a hypothetical ship-born child, I always have to option to opt-out if I truly believe I would be better off not existing.

Re:Sterile and shattered.

[Immerman]

You always have the option to opt out. But there's only two choices we're certain of - play the hand you're dealt, or stop playing entirely.

Re:Sterile and shattered.

[0111 1110]

Our most efficient drive system to date (in terms of how much acceleration you get for the amount of propellant used) are plasma/ion engines.

Has anyone actually proposed using those for even short interstellar missions? Since no one has actually even tried to build a craft for an interstellar mission no one has done the full engineering required but nuclear pulse (Orion) or fission fragment / dusty plasma fission engines could likely make Alpha Centauri in less than a century reaching speeds of .05 - .08c.

The ships could not be launched from earth and so would have to be constructed either from orbit, at a Lagrange point station, or on a moon base with nuclear power plants and mostly automated robotic mining/smelting/casting/milling capabilities. Just building the infrastructure to build such a rocket would probably take a century or two, but it's probably doable to build something like that with current tech. Just some (a lot of) engineering problems to work out. No fundamental advances necessary. Just a lot of money. I think Orion has been more fully engineered (by Freeman Dyson) than fission fragment. So might be more doable. Needless to say it would be expensive, but I'm guessing you'd be for it even if you had to sacrifice say an extra 10-15% of your income am I right? I'm sure we can all agree on 'anything to reach the stars'.

Re:Sterile and shattered.

[saloomy]

Thanks for the reference. Isn't local interstellar medium unnaturally devoid of hydrogen due to the relatively strong gravitational pull of the sun. Once you get out far away from most stars, the density evens out? Guess my knowledge is outdated.

Re:Sterile and shattered.

[bobbied]

We are talking about something like 100 parts per million increase in C02 over the last century of burning fossil fuels... That 100 ppm sits on top the natural CO2 in the atmosphere and really only represents a few percent of what is there naturally. Yes it's up, but we are discussing a dynamic system that deals with CO2 naturally, and as you point out it's effectively dealing with the bulk of the extra we put out. One would *expect* the concentration to increase a lot more, given what we are pumping into the air. The system will achieve steady state again, likely with a higher CO2 concentration than we see in the past records, but not above what the Earth has survived before, even if we burned every last scrap of fossil fuels we could find in one day.

We are having an effect, but how much can an extra 100 parts per million actually do? It's seriously nearly nothing, both in the amount of carbon following though the cycle each year and the net affect it can possibly have. I know some folks are totally freaked out over this, but when you look at the grand scheme of things and realize the really small of a fraction this really is of our atmosphere and start looking at the scales on all those alarming graphs and charts with the red arrows going straight up, it's not really all that likely to be a problem. Certainly it's not a problem you can hobble your economy and national security in a vain effort to fix but I digress.

Re:Sterile and shattered.

[h33t l4x0r]

The moral and ethical questions alone should make that obvious. How can you condemn future generations to carry a mission they didn't have any say about, may not wish to participate in...

You could say the same about The Mayflower. That worked out OK, didn't it?

Re:Sterile and shattered.

[Immerman]

Where are you getting "a few percent" from?

There's only 400ppm total CO2 in the atmosphere, that 100ppm represents fully 25% of the total.
Perhaps you're thinking of the fact that CO2 is only a few percent of the total atmosphere? But that's largely irrelevant because almost all atmospheric gasses are completely transparent to thermal infrared radiation, and so don't provide any insulation at all. If they were the only things in the atmosphere the Earth would be as cold as the moon (colder actually, the moon is actually coal black and thus a good thermal absorber)

Water vapor, CO2, and methane are responsible for the overwhelming majority of Earth's atmospheric insulation. Water makes up about 0.4% of the atmosphere (mostly at low altitude), CO2 is about 0.04% of the atmosphere,and methane 0.0002%.

Water is obviously the biggest contributor, but it can't build up in the atmosphere since it rains out as the concentration builds, so it remains fairly constant at a given temperature. It's worth nothing though that it acts as a positive feedback system - the warmer the planet, the more water vapor builds up in the atmosphere, and the more heat will be trapped. So it will tend to make any global temperature changes more extreme.

Methane is actually a considerably more powerful greenhouse gas than CO2 per pound, but there's so little of it that it still only traps a fraction as much heat as CO2. It's also worth mentioning though that humans are estimated to be responsible for somewhere around 2/3 of global methane emissions - we're working hard on that front as well.

Which leaves CO2 as a sort of "thermostat" - more CO2 leads to a warmer planet and faster plant growth, which pulls CO2 out of the atmosphere leading to a cooler planet and slower plant growth, which lets CO2 build up in the atmosphere again... it's a self-stabilizing system that oscillates around some "average" point until something disrupts it - such as dumping carbon into the atmosphere that's been locked underground for millions of years.

As for what difference a few percent can make? Lets do some rough math. Say CO2 is responsible for about 10% of the total greenhouse gas "insulation" (I have no idea, but it makes up about 10% of the total greenhouse gases in the atmosphere so that seems like a good guess). The 100ppm increase would therefore be responsible for about 2.5%. That means the Earth will have to warm up enough to radiate 2.5% more heat in order to shed the same amount of energy through the insulation to restore the energy balance and stop heating up. The amount of heat radiated is proportional to the fourth power of temperature, so a 2.5% increase in radiant heat translates to ...1.025^(1/4) = 1.006... a 0.6% increase in temperature. Earth currently averages about 61F, or 289K in absolute terms, and a 0.6% increase of that translates to 1.8K, or about 3.2F.

A three degree increase doesn't sound terribly catastrophic all on it's own, but that's assuming nothing else changes, which isn't the case.
First off as things warm up we'll have more water vapor in the air, further increasing the amount of insulation.
More dramatically, the warming isn't uniform - the poles are heating much faster than the rest of the planet, which means those shiny white ice "mirrors" that currently reflect sunlight back into space before its absorbed are being replaced with dark sunlight-absorbing water. That means the planet is absorbing more energy from the sun, and it's going to heat up even further until it's radiating all that extra energy back into space as well.

And of course there's the rising oceans to contend with: water has a coefficient of expansion of 0.00012/*F, and the oceans have an average depth of about 12,100 feet. 12,100feet x 3.2*F x 0.00012/*F = 4.65 feet. So even without any icecaps melting, the ocean would rise that much. Which maybe doesn't sound too terrible, but something like 90% of the worlds population live within 10 feet of sea level. That's going to b

Re:Sterile and shattered.

[djinn6]

The ships could not be launched from earth and so would have to be constructed either from orbit

Orion was actually designed to take off from the ground, so no, you don't need to build it in space unless you're worried about radioactive fallout, which could potentially kill a handful of people across the globe by ever so slightly increasing cancer rates.

Orion can launch several hundred tons to orbit using very tiny nuclear bombs (0.03 kt). It wouldn't be too hard to scale up the ship by scaling up the bombs. It'll take a few tries before we're launching millions of tons, but we'll get there pretty quickly. At that point, everything is easy, because lots of problems (and expenses) of space travel basically goes away. Radiation for example, isn't a problem if you can have a 20-foot thick wall of water containers surrounding the ship. Energy is easy because you can run a full-scale nuclear power plant onboard. Living space is no problem, nor food and oxygen production.

Now, I'm sure that building so many nuclear bombs would cost a lot of money. About $2 million each. But even building the 20,000 you'll need for the trip is still in the same price range as the ISS, which costed $150 billion.

Re:Sterile and shattered.

[SandorZoo]

I think that greatly depends. Without a strong magnetic field, the Earth would look a lot like Mars, with much of its ancient primordial atmosphere blown away.

I don't see why that's a given. Venus doesn't have much of a magnetic field, but has plenty of atmosphere.

Re:Sterile and shattered.

[SandorZoo]

As well as the Bussard Ramjet you describe, there's also Robert L. Forward's idea of Starwisp, an extremely light weight maser powered "light" sail that's rapidly accelerated up to 10% lightspeed, and then coasts the rest of the way. It won't be able to slow down, so can only do a high-speed flyby of its destination star system. There it would use its launch maser a second time, this time to power instruments and transmitters.

Re:Sterile and shattered.

[Ihlosi]

There's only 400ppm total CO2 in the atmosphere, that 100ppm represents fully 25% of the total.

And 25% is not a YUUGE number if you think big enough. It's just a few percent. What harm can that do?

Re:Sterile and shattered.

[dave420]

You are basing your entire argument on guesses. That might allow you to come to comfortable conclusions, but they are not based in reality.

Re:Sterile and shattered.

[bobbied]

And your side isn't guessing? LOL

Re:Sterile and shattered.

[bobbied]

So you are proposing that we push the space craft along by detonating nuclear devices behind it?

Well that might actually work in theory, but there ARE some serious potential problems to discuss.... What is pushing the craft along? In this case it seems it would be both radiation and high speed matter impacting the craft. This doesn't seem like a long term solution, because neutron radiation is pretty destructive in the long term because it can change the chemistry of the stuff it hits, is really hard to effectively shield (or at least such shields are really heavy), and the physical heating/cooling of the outside of the craft will be a serious long term risk due to work hardening of the metals.

The real problem ends up really being duration. It's not that radiation shielding doesn't exist, but that given the time frames we are discussing are in the order of multiple decades to centuries, the current technology wears out long before the mission would be over.

Remember, there is no resupply, no sending spare parts or refueling, you have to take everything needed with you when you depart the solar system. And what you take will need to last half a century or more....

Re:Sterile and shattered.

[bobbied]

Succeeding generations of Pilgrims had (and still have) the option of returning to where they came from.

A "generation ship" has no such luxury. It's NOT going to be possible for somebody to return once the mission is underway. You and your progeny are stuck while Sir Isaac Newton and possibly Einstein are driving. There are no ships home coming within your lifetime. For you it's a one way trip and other than killing yourself, you have zero say about how your life will be spent.

Is it moral and ethical to do this kind of thing to generations? Effectively force them to be slaves of the "mission" like it or no? I'm not so sure we can absolutely say it is.

So for any mission that lasts longer than the expected lifetime of the people that choose to go, there are some thorny ethical questions to ask and resolve.

Re:Sterile and shattered.

[Immerman]

Hyuck hyuck.

But I already answered. Even assuming it's only 2.5% of the total atmospheric insulation, we'd be talking about 3.2F of heating, before even considering knock-on effects

Re:Sterile and shattered.

[DarthVain]

That was my concern buried in the article. The fact that these planets because they orbit so close to their star are likely tidal locked. Meaning one side all sun, the other none. Now I can get behind the whole idea that it wouldn't totally be an block to life, I'd even go so far to say in such occurrences perhaps a "ring" of life when light and temp are moderate around the border...

However what I am curious about is the magnetic field. From my understanding, a planets magnetic field is largely produced by the rotational action of a molten core. What I am not sure of is if that core would rotate in a planet that isn't itself rotating. Being tidal locked, they would not be, or would they be, just only in sync with the orbit of the sun, and if so is that orbit fast enough (though apparently they are pretty fast) to generate a rotational molten core? As without it, no magnetic field, and without that field the likelihood of life likely drops pretty precipitously.

Re:Sterile and shattered.

[bobbied]

Because our ancestors didn't have a choice did they? Or perhaps you think they did? Did somebody in the distant past decide for all future generations that they where stuck here?

Seriously... So unless you can claim somebody in the past made the moral decision to just dump us off here, we are not talking about the same thing.

Unless of course you do believe that was a choice made by some ancestor.... In which case we need to have a talk...

Re:Sterile and shattered.

[bobbied]

Really? So the laws of Physics just might be discovered wrong in the future?

Perhaps our understanding of Physics will change and interstellar space travel will be proven possible, but I'm not holding my breath on that. Einstein and Newton where bright guys and their explanation of Physics seems to be fairly well established. Until we have some major revision to these theories, it isn't happening.

Re:Sterile and shattered.

[syntotic]

Someone should find a better measure than light years. Makes you calculate in terms of your natural life, not thousands, or even hundreds of year.

Re:Sterile and shattered.

[syntotic]

Both choices look equally good! Visit back unknown Earth which their parents may still vilify, OR establish yourself in an unknown world completely YOURS! Sounds like a programming chore: define cases launching generation, in between generations type no fuel, type refuel and back... define last arriving generation, define first settlers generation or research and launch back generation... up to returning generation. Then administer them Earth library information the right way to not make them think of coming back, or on the contrary, to want them ONLY to come back Home. Would you include previous slashdot pages in their information luggage?

Re:Sterile and shattered.

[syntotic]

Space travel IS impossible for HU-MANS. But very little prevents the existence of very long lived, slow and sentient beings for whom this discussion is just nuts. Maybe we can date when such a species must have developed in the story of the universe making assumptions as to their information capabilities, operation modes, frequencies, etc., to make space travel like a walk in the countryside. So we jus have to extend our lives and make our brains slower to assimilate any speed we can produce physically to make this worth the while, sic.

Re:Sterile and shattered.

[0111 1110]

Orion was actually designed to take off from the ground, so no, you don't need to build it in space unless you're worried about radioactive fallout, which could potentially kill a handful of people across the globe by ever so slightly increasing cancer rates.

Well why shouldn't we be worried about nuclear fallout? It is simply never going to happen and not just because of the nuclear test ban treaty. NASA can barely manage to launch RTGs into space without the public freaking out about it. It will be hard enough to get support for the billions or even trillions of dollars necessary for a pulsed nuke starship that launches outside the atmosphere.

Freeman Dyson was doing small scale engineering/testing for an interplanetary mission not an interstellar one. The size and mass of the craft would have to be scaled up significantly and even if it could be launched from the ground I don't think that would be a very efficient way to do it and would require a lot more nuclear bombs detonating in the atmosphere. We should be thinking in terms of permanent lunar and Lagrange point stations anyway.

Re:Sterile and shattered.

[djinn6]

Well why shouldn't we be worried about nuclear fallout?

Because eating a banana will give you more cancer risk than this launch.

Freeman Dyson was doing small scale engineering/testing for an interplanetary mission not an interstellar one.

No. They planned for Mars, but also did the calculations for crafts up to 8 million tons.

... even if it could be launched from the ground I don't think that would be a very efficient way to do it and would require a lot more nuclear bombs detonating in the atmosphere.

It needs 800 nukes to get into orbit. Again, if we assume $2 million per warhead, this come out to $1.6 billion, or $0.20 per kg. Compare that to Falcon 9's $5,500 per kg price. This is very cost-efficient.

Re:Sterile and shattered.

[david_thornley]

About 520 atmospheric nuclear tests have taken place. You're proposing to exceed that with one launch to orbit. Are you sure you're not missing some problems here? EMP? Destroying satellites? Putting stuff we don't want into various layers of the atmosphere?

Not to mention that this involves producing standardized nuclear devices in very, very large numbers, and each and every one has to be guarded and accounted for. If terrorists get their hand on some kerosene and liquid oxygen from a modern launch, that isn't a major problem. If terrorists get their hands on a little Orion propellant, we do have a major problem.

Most of the work on Orion was done during the search for peaceful nuke uses, which turned out to be really disappointing. We know more and we understand more problems now.

Re:Sterile and shattered.

[djinn6]

Size matters. Those 520 tests includes many multi-megaton weapons. The 800 puny 0.03 kilo-ton weapons add up to less power than Little Boy and Fat Man combined. And since they're thermonuclear weapons, they're much cleaner than either of them.

Everything nuclear pulse propulsion does, we have already done a thousand times much worse with atmospheric tests. And keeping them safe is much easier than our current stock of nuclear weapons, which for military reasons must be placed all across the globe at many different locations.

Re:Unlikely

[Anonymous Coward]

Yeah, because it's so much more likely that what they're seeing is a megastructure or dyson-like object.

Names for 7 planets orbiting a red dwarf star

[jfdavis668]

How about: Bashful, Doc, Dopey, Happy, Sleepy, Sneezy and Grumpy?

Re:Names for 7 planets orbiting a red dwarf star

[MightyMartian]

If they name them after Donald Trump and his family members, NASA will probably get a trillion dollars a year.

Re:Names for 7 planets orbiting a red dwarf star

[jfdavis668]

Relevant xkcd: http://xkcd.com/1253/

Re:Names for 7 planets orbiting a red dwarf star

[randomlygeneratename]

Or what about Sneezy, Phylum, Europe, Sloth, Guacamole, Data Link, Colossus of Rhodes? https://www.xkcd.com/1417/

Re:Names for 7 planets orbiting a red dwarf star

[c]

How about: Bashful, Doc, Dopey, Happy, Sleepy, Sneezy and Grumpy?

I'm sorta expecting New China, New Russia, New India, New Brazil, New France, New Australia, and Trumpworld.

Re:Names for 7 planets orbiting a red dwarf star

[Applehu Akbar]

Relevant xkcd: http://xkcd.com/1253/

I would rather see naming rights auctioned off to the highest bidder, with the proceeds to benefit space research. Let the human ego do some good.

Re:Names for 7 planets orbiting a red dwarf star

[jfdavis668]

And there will be a Disneyland on each one, but no one will go to the one on New France.

Re:Names for 7 planets orbiting a red dwarf star

[Tablizer]

The last one offended the first six and is building a Dyson sphere around them and making them pay for it.

Re:Names for 7 planets orbiting a red dwarf star

[theurge14]

Waist-Deep Cats always gets me.

Re:Names for 7 planets orbiting a red dwarf star

[elgatozorbas]

How about: Bashful, Doc, Dopey, Happy, Sleepy, Sneezy and Grumpy?

Get it over with and call them Achel, Chimay, Orval, Rochefort, Westmalle, Westvleteren and La Trappe already!

Anything else would be blasphemy. Yes, I am Belgian. :-)

Re:Names for 7 planets orbiting a red dwarf star

[certsoft]

How about New New Zealand?

Re:Names for 7 planets orbiting a red dwarf star

[arth1]

How about: Bashful, Doc, Dopey, Happy, Sleepy, Sneezy and Grumpy?

That's appropriate because by definition, they are dwarf planets, even if bigger than Earth. There are only 8 "real" planets according to the rules makers. Nothing orbiting a different star can qualify, according to the hastily made rules designed to exclude Pluto. But you can call pretty much anything that doesn't qualify a dwarf planet.

Re:Names for 7 planets orbiting a red dwarf star

[sysrammer]

"Trumpworld"

NewtRumpLand.

Re:Names for 7 planets orbiting a red dwarf star

[psmoot]

If they name them after Donald Trump and his family members, NASA will probably get a trillion dollars a year.

Only if he moves there first.

Re:Names for 7 planets orbiting a red dwarf star

[MightyMartian]

I don't mean to be braggadocios, but this is going to be the Yugest interstellar empire ever!

Re:Names for 7 planets orbiting a red dwarf star

[Quirkz]

Can I get a New North New South Wales?

Re:Names for 7 planets orbiting a red dwarf star

[Trogre]

I think you mean Lister, Rimmer, Cat, Kryten, Holly, Kochanski, Ace.

Re:Names for 7 planets orbiting a red dwarf star

[Trogre]

According to Dave Barry in the 80s, Mars should be called Planet Trump by now.

Re:Names for 7 planets orbiting a red dwarf star

[jfdavis668]

Would that make the other place Old New Zealand?

Re:Names for 7 planets orbiting a red dwarf star

[Xyrus]

Planet McPlanetFace

Re:Names for 7 planets orbiting a red dwarf star

[TechnoJoe]

Why not name them after Trump? First 100 days. He's getting it done.

Re:Names for 7 planets orbiting a red dwarf star

[CanadianMacFan]

I'd kick in a few bucks to send him right now.

Re:Unlikely

[MightyMartian]

Well yes, much in the same way one infers the presence of a stream of electrons from an electrical charge or the Big Bang from the CMBR, relative proportions of hydrogen, helium and lithium in the Universe and the red-shift of distant galaxies. Even a particle accelerator like the LHC at CERN does not in fact directly image subatomic particles. For chrissakes, what you "see" isn't a raw image, but is heavily processed by your nervous system, beginning right at the retina itself, then by the optic nerve and then by visual centers in the brain. In other words, what you "see" isn't actually the photons that the physical structures of the eye captures.

Lots of science is inference, seeing as many phenomenon cannot be directly observed. If you're saying inference is somehow questionable, then you're basically calling all form of observation questionable.

Yeah not going to visit

[SuperKendall]

Why would I not want to visit other planets that are the most likely so far to contain life?

Simple - it's a Trappist!

Re:Yeah not going to visit

[Jason Levine]

If one of those planets is found to contain a lot of liquid water, we should name it Mon Calamari.

"What star does Mon Calamari orbit again?"
"It's One Trappist!"

Re:What makes this special?

[jfdavis668]

One, they are fairly close. Two, the interaction of multiple bodies lets you determine far more information about their size.

Re:Unlikely

[Cealestis]

I have no idea what you're talking about. They used photometry to detect the planets... They see a dipp in the light curve of the star as the planets block some of the light.

I knew Wheeden was from the future...

[grebonoj]

Anyone note how similar this system is to the solar system in Firefly?

Re:I knew Wheeden was from the future...

[mark-t]

Except for the fact that the Firefly 'verse had "dozens of planets and hundreds of moons", sure. I'd say that to measure up to that, it would need at least 3 or 4 times as many rocky worlds as they've found in what seems to the habitable zone in the Trappist system, and probably have another dozen or two of gas giants in the habitable zone as well.

Re:What makes this special?

[TheDarkMaster]

This discovery expands the possibilities of planetary configurations. This suggests for example that the number of rocky planets can be even greater than what is currently envisioned and the greater the number of possibly habitable planets then most likely to find life in some of them.

Alliance

[queequeg1]

This must be where we eventually go to form the Alliance.

Re:Unlikely

[bobbied]

Even more.. They are estimating the size and orbits of these planets and using all this estimation they figured that one or more of these planets *might* have liquid water on the surface. So assuming all their decades of observations are enough to correct out all the observation errors are good enough and matches their math close enough, they are likely right.

However, you are correct, we are not detecting these using any kind of direct observation but though inference from other observations that might indirectly indicate the presence of some number of planets.

Re:Thrilling?

[MightyMartian]

Finding that many Earth-sized rocky bodies orbiting a star just 39 lightyears away, with the possibility that some of them may be able to have liquid water on their surface doesn't excite you? Did you have your sense of wonder and curiosity surgically removed?

Re:Unlikely

[xevioso]

These were found using the transit method, which measures a star's reduction in it's brightness as something passes in front of it.

They know that these sorts of occurrences are not things like sunspots because they can follow up using measurements of the wobbling of the star due to the gravity the planets exert on it.

Combine the two and you have a reasonable inference that there are planets orbiting this star.

If these are not planets, given the above two types of evidence correlating with each other, what else could they be?

Re:What makes this special?

[MightyMartian]

I wonder if, being close to their star, gravitational interactions between the planets and between them and the star could lead to the necessary "churning" of at least some of their cores to produce a strong magnetic field.

Re:The star is named Trappist-1

[cyberchondriac]

Chimay be right, chimay be crazy..

Re:The star is named Trappist-1

[jfdavis668]

Future colonists would appreciate that.

The Fleet of Worlds

[Anonymous Coward]

This sounds like the Fleet of Worlds of Larry Niven's Pierson's Puppeteers.

Re:The Fleet of Worlds

[jfdavis668]

But they got rid of the star. I think Larry Niven predicted everything.

Re:The Fleet of Worlds

[HiThere]

So how fast are they moving? And in which direction?

Re:Thrilling?

[The-Ixian]

Well? What did you decide?

Re:Thrilling?

[BundesSheep]

So what's the verdict?

Re:Thrilling?

[penandpaper]

It will excite me more if there are some alien honey's that sport an anthropomorphic hourglass if you catch my drift. ;)

If I learned anything from Star Trek it's that it isn't bestiality if it's non-terrestrial. Thank you captain Kirk.

Re:Overshadowed by systemic racism.

[MightyMartian]

I'm glad you've recovered so quickly from Milo's downfall.

Re:Unlikely

[Anonymous Coward]

aliens are trolling earth astronomers by setting small neutron stars in orbit around suns.

Belgian beer

[Framboise]

Remember, as the Trappist name indicates the whole system is dedicated to Belgian beer.

Re:That's not true! That's IMPOSSIBLE

[slimshady76]

He knew probably on Monday, so that gives him a couple more days to create life before his day off. Tell him to have a few beers on me if he meets the deadline.

Re:Thrilling?

[SuricouRaven]

Your guide to distant worlds:
http://i.imgur.com/6jp4DVK.png

Re:Thrilling?

[penandpaper]

i giggled. thanks.

Ah but as Douglas Adams would have said

[presidenteloco]

An unlikely impossibility is equivalent to a likely possibility, not to be confused with an infinite improbability.

A small, ultra-cool star

[wonkey_monkey]

a small, ultra-cool star.

What you talkin' 'bout, NASA?

Re:A small, ultra-cool star

[Tablizer]

Those are similar to Gnarly Class stars.

Re:Thrilling?

[Anonymous Coward]

Flawed! I don't know what "consentual" means, but surely don't rely on ASKING when determining if an alien is old enough. The alien I fucked SWORE to me it was 22, then I find out it's planet circles its sun every 90 MINUTES!

Let's set up a telescope array on the moon now

[presidenteloco]

No seriously, we should set up a very large synthetic aperture array of telescopes on the far side of the moon to look at these and similar promising exoplanets in high resolution and spectroscopically etc.

Yes. I know the far side of the moon isn't always dark, but half the time it is, and is shaded from Earth's light and our EM emissions etc.

Re:Let's set up a telescope array on the moon now

[Gavagai80]

Until we have manufacturing facilities on the moon (not happening this century), it's easier to just launch another space telescope.

Re:Let's set up a telescope array on the moon now

[Immerman]

EM transmissions are the only real issue, and does in fact make the far side of the moon an attractive location for radio telescopes. Anything more optical though is better off in orbit. Just don't look towards the Earth won't see any Earthlight, sunlight is a far more powerful, and we block that out easily enough.

And orbiting has one *huge* benefit over anything built on a planetoid - you can keep your telescope pointed at the same spot indefinitely without any seismic disturbances, and those extremely long,stable exposures are critical for getting a good image from the few photons that happen to be coming in our direction.

Also, for actually seeing the surface of an exoplanet in enough detail to get more than a few pixels from the whole planet, I think you'd probably want to build a gravitational lens telescope such as FOCAL. Of course that's a somewhat long-term project, and you have to choose your target carefully. Voyager 1 is currently only about 10% far enough away from the sun to use its gravity as a lens. At 550AU it's going to take an awful long time to change your position relative to the sun by even a single degree.

Re:Let's set up a telescope array on the moon now

[Baron_Yam]

>And orbiting has one *huge* benefit over anything built on a planetoid - you can keep your telescope pointed at the same spot indefinitely without any seismic disturbances

Except that Earth orbit involves having the Earth block your view a lot of the time, and the Moon can block or blind you, too.

Solar orbit is a lot less convenient for repair missions, but you can get much, much longer undisturbed exposure times if that's what you're looking for.

Re:Let's set up a telescope array on the moon now

[Immerman]

That only applies to looking at things in the plane of the solar system. If you look at right angles to that, then nothing local but the occasional asteroid will ever pass in front of you. And you can look pretty close to the plane as well, even the sun is only 0.5 degrees across as seen from Earth, meaning most of the sky is completely unobstructed.

Of course for something like the Hubble in a low-Earth orbit, the Earth is a somewhat bigger problem. But they conveniently placed it in a non-ecliptic orbit, so it has a pretty huge amount of unobstructed sky, the particular part of which change gradually over the course of a year. So, even if they want a long exposure of something in the ecliptic plane they can do so, they just have to wait for the time of year that they'll have a clear view. As it is, the Hubble Ultra Deep Field image is the longest exposure ever taken, at 50 days, and that represents a phenomenal opportunity cost in terms of other things that could have been looked at instead.

And of course, the higher the orbit, the less of an obstruction the Earth presents. By the time you reach geosynchronous orbit, the Earth is only about 26 degrees across.

Re:What makes this special?

[bobbied]

What is different about these planets?

They are closer than any other ones we have found...

Re:Thrilling?

[Applehu Akbar]

More importantly, even, are that we can detect planets that small at this distance, and that such a small and cool star, the most common kind, has rocky planets. If the Copernican assumption holds, there are a lot more planets of this kind waiting to be discovered.

Re:Overshadowed by systemic racism.

[MightyMartian]

Because being a pedophilia defender is the surest way to fame and fortune...

I love how Milo's fanbois still desperately cling to the idea that he's going to make his way out of this one, even as he becomes too toxic for even Breitbart.

Not in this political climate

[tekrat]

The President doesn't want to hear about the possible presence of more aliens!

Re:Not in this political climate

[KingOfBLASH]

The President doesn't want to hear about the possible presence of more aliens!

This is exactly what we need right now!

1. Tell everyone aliens exist in outer space
2. With backing from the middle class, invest heavily and push to build space faring technology so we'll be able to deport the aliens, and build a space wall
3. Inadvertantly figure out how to build a dyson sphere
4. Free energy for life; civilization upgraded to a spacefaring nation

Re:What makes this special?

[lgw]

Welcome to astronomy.

Re:Thrilling?

[codeButcher]

I thought the fact that the star is "ultra-cool" is the most exciting thing about this story...

Maybe we can send all the hipsters there?

Pluto is a planet.

[IGnatius T Foobar]

Pluto is a planet. I don't buy the #FakeAstronomy.

Re:Overshadowed by systemic racism.

[lgw]

Wasn't he the victim of sexual abuse? I don't follow him, so I don't know exactly what he said, but that's the sort of circumstance that a reasonable person makes allowances for.

I'll sleep better now

[Tablizer]

spotted seven Earth-sized planets orbiting closely around a small star...39 light years away.

That's where God keeps Earth's backups.

I wonder how far back the oldest goes?

Re:I'll sleep better now

[psmoot]

spotted seven Earth-sized planets orbiting closely around a small star...39 light years away.

That's where God keeps Earth's backups.

I wonder how far back the oldest goes?

With seven of them? Clearly a weekly full and daily incrementals.

Re:I'll sleep better now

[wbr1]

Lets find out:

$sudo -u god mount -t godfs /dev/trappist1p1 /mnt/p1folder
$Error: Username:god not in sudoers file

Re:I'll sleep better now

[Tablizer]

Error: Username:god not in sudoers file

Try "allah".

Re:I'll sleep better now

[wbr1]

Yes, I mostly wok in windows, due to my clients needs. Used to sysadmin various unix boxes. I also go back far enough to where it was Doss or nix directories not folders. Been doing this since 1994.

However, folders is less syllables, easier to say, and understood by all.

Dude, that's like a triple negative.

[Anonymous Coward]

I don't see how it is improbable that they could not harbor life.

Quote of the day! I had to apply Boolean algebra to deduce your actual meaning.

Re:Dude, that's like a triple negative.

[MightyMartian]

Wow, rereading it, talking about clunky. Logically and grammatically correct, to be sure, but Jesus Christ, how did I ever manage to weave that set of words together. Ouch!

Re:Dude, that's like a triple negative.

[bazorg]

It's all good... if you're commenting on Trappist aliens it's only right that you drink a few beers as you type. :)

Challenging?

[Immerman]

Seems like it probably wasn't much of a challenge, besides being lucky enough to look in the right place. Planets that close to the star will generate a comparatively strong signal, especially if they used Doppler shifts rather than transits to detect them. And with orbits varying from 1.5 to 20 days it doesn't take long to get many periods worth of signal to be confident in your detection.

Recognizing that they had seven overlapping signals rather than random noise was probably the most difficult part, and that probably wasn't too difficult with modern technology.

Re:Challenging?

[harperska]

They used the transit method. But even the transit method will give a stronger signal the smaller the star. The shadow of a terrestrial sized planet will be a larger percentage of the total stellar output.

Re:Challenging?

[Immerman]

Even better. The transit method means we should be able to analyze their atmospheric composition, assuming they have one.

Re:What makes this special?

[Anonymous Coward]

Fairly close, lol. Because one mind-bogglingly distant object is an order of magnitude or so less astoundingly far away than some other mind-bogglingly distant object is no excuse to use an adjective like "close".

C'mon, its a relatively good excuse.

Re:Unlikely

[Immerman]

>If these are not planets, given the above two types of evidence correlating with each other, what else could they be?

Giant non-invisible teapots.

Re:Thrilling?

[Anonymous Coward]

It's not that exciting. No human will ever see it or visit it, so who cares?

Um, it was discovered using optical telescopes. That means we can see it, it's close enough that with a lot of long exposures, they should be able to get atmospheric composition data. (That's why it's exciting by the way.)

What it says about this world

[execthis]

It's a sad commentary about the state of affairs on this world that access to the original article, based on research on paid for with public money, is no free. It's truly appalling.

Re:What it says about this world

[StupendousMan]

You can see the figures here for free --- and they provide much of the meat of the study.

http://www.nature.com/nature/j...

Re:Unlikely

[Kjella]

If these are not planets, given the above two types of evidence correlating with each other, what else could they be?

Star Wars XII. "That's no planet... it's a space station"

Sterile and shattered. Or Not

[Immerman]

Where are you imagining earthquakes from? If the planets are tidally locked, then their sun would no longer be having any substantial effect on their crusts. Much like the moon doesn't suffer quakes due to being tidally locked with the Earth, unlike the Earth whose crust is constantly being flexed by the gravity of the moon and sun. In fact, being tidally locked likely *reduces* the tectonic activity, since there's no longer any tidal "massaging" of the crust.

As for the x-ray blasts - I admit that's bad news for anything on the sunny side of the planet. A complete non-issue for anything on the dark side planet though - a few thousand miles of rock makes for extremely effective x-ray shielding. Unless of course those X-ray bursts are accompanied by coronal mass ejections - over time those would tend to strip away the atmospheres of any planet without a strong enough magnetosphere (a complete unknown at this point)

On the exciting side, since they detected these planets by observing their transit across the face of the star, there's the potential for us to analyze the changes in the star's light as it passes through their hypothetical atmospheres, letting us determine if they exist, and if so what they're primarily made from.

Re:Sterile and shattered. Or Not

[Immerman]

The moon has quakes, but only the incredibly mild deep moonquakes (700km below the surface) are potentially caused by tidal effects. And it's probably a safe bet that those are *solar* tides rather than Earth tides, since the only Earth-caused tides are the very slight fluctuations caused by the Moon's slightly eccentric orbit and the associated libration. Meanwhile the sun will still be causing tides on a roughly 30 day period (as I recall, on Earth solar tides are about 50% as high as lunar tides - which is why tides are highest during the full and new moons, when Earth, moon, and sun are all aligned.)

Re:Sterile and shattered. Or Not

[Immerman]

Yes, but they're mostly not *tidal* quakes, and those that might be are are almost certainly due to solar tides, as the moon has only *very* slight earth tides due to libration.

Re:Sterile and shattered. Or Not

[Immerman]

No, rotation isn't required for tidal forces, just for those forces to substantially "massage" a planet. Just squeezing the planet doesn't add heat, the squeeze needs to be changing to generate substantial heat.

It's true you'll still get some tidal effects due to eccentricity, but they'll be far smaller than if the planet was rotating - if you imagine the tides squeezing a stress-ball into more of a football shape, rotation means the bulges are traveling around the planet once per day. Without rotation you'll get just a slight change in how tight you're squeezing as the planet move closer and further from its primary, as well as some very slight oscillation of the bulge across the surface due to the associated libration.

I suppose though if we're talking about tight orbits around a huge primary, even a tiny fraction of the original tidal effects could still be quite large.

Hmm, and there will be another effect as well - that of the pulsating "tides" from the other planets - after all the distance between their orbits ranges between only about 2x and 4x that between the Earth and Moon, except for the outermost at ~6x the distance. That would be a factor with Jupiter's moons as well. I wonder how the magnitude of the effect would compare?

Re:Thrilling?

[penandpaper]

Excuse me, but I don't think you saw my sig that I most certainly did not just change right now.

Let's go

[bdrasin]

EOM

They forgot to mention X-Rays

[little1973]

Strong XUV irradiation of the Earth-sized exoplanets orbiting the ultracool dwarf TRAPPIST-1

https://arxiv.org/abs/1605.015...

Re:Overshadowed by systemic racism.

[MightyMartian]

I can certainly understand why he is a pretty vile human being, but that doesn't going any distance towards defending him.

My honest view is that he has no sincerely held views. I think he just says things to piss people off, and has gathered together a following of young white men in their late teens and early twenties who think that it's really cool to be a repugnant bigot. I don't think that has anything to do with whether Milo was the victim of abuse as a child, and everything to do with the fact that he's an entertainer who has a following to immature and stupid to realize that he's playing them for laughs and giggles.

But even the further end of the conservative spectrum, while certainly happy to openly despise women and minorities, still have pedophilia as possibly their only remaining red line.

Re:Not a reason to make allowances at all

[lgw]

Something like 30% of victims become pedophiles themselves. So while this goes some way toward explaining his toxicity (only some-way mind you, since plenty of victims choose not to become vile, despicable people, unlike Milo), it certainly does not warrant "making allowances for."

"Pedophile" != "child molester". Not sure which you meant here. But didn't he say something like "I was molested and it wasn't that bad"? (I don't actually know.) I'm no psychologist, but from what I understand that's a sort of mental illness caused by trauma.

Re:What makes this special?

[Immerman]

Hey, just because you think it's a long walk to the grocery store, doesn't make that any more of a absolute yardstick.

In the context of astronomy, 39 light years away is practically in our back yard - close enough that one day we may build telescopes capable of directly viewing the planet surfaces in enough detail to tell if there's (obvious) life there.

And it's well within the range to which we can send probes in the relatively near future (say within a century). As I recall we've already got a project going to design a postage-stamp sized probe that can cross the 4.2ly to Proxima Centauri in only a decade or so.

Re:What does '2000 times fainter' really mean?

[Immerman]

Try reading, it does a mind good.

1x fainter doesn't mean anything more than 1x larger - i.e , the same.

2x fainter means 1/2 as bright. 2000x fainter means 1/2000th as bright. Pretty standard terminology.

I think its time we hack space travel.

[darkharlequin]

I've been working on putting structure to MIT's OCW courses and filling in the blanks where there's missing courses. If we all tried to just go through what is available out there now and focussed on propulsion, life support systems, systems engineering, etc, I think we could get ourselves off the planet and mining asteroids to build craft that could get to this system without having our work belong to any organizations that could keep it to themselves. I know that's quite collectivist for a capitalist, but I believe that math/basic science shouldn't be patentable, and the only way to do this is to race against those who intend to patent everything. I put my thoughts up on Hive13's wiki and moved them to http://hackereducation.wordpre... I am not a professor and I only had 2 years as a college software system architect, so my understanding of curriculum development may need help, but it doesn't matter if the idea grows into something better. We have a way to use sunlight to fuse glass https://www.youtube.com/watch?... and probably could use these: http://www.growbiointensive.or... guys' ideas to grow food. No idea since I'm a physics/cs guy and not a biologist or doctor. I just wish we'd stop waiting for the government to do everything for us and use the damned hand rectangles that contain all of human knowledge to learn ourselves and then go do it!

Re:I think its time we hack space travel.

[iggymanz]

I'm having a very hard time seeing how a spacecraft could NOT contain an immense amount of patented tech. I don't think it's possible to make a patent-free spacecraft.

Any craft that can reach a star system 39 light years away in a reasonable amount of time is also a fearsome weapon.

Re:I think its time we hack space travel.

[darkharlequin]

What about Soyuz, gemini, skylab, or Apollo? Most of that technology should have gone out of patent if there was any. I know Lockheed has a lock on Orion for the moment, but that shouldn't mean we can't try. I just want the basics--enough for people willing to take the risk to go out and try to mine asteroids. I think if we can get that then things will snowball like they did with the USA.

Re:I think its time we hack space travel.

[KingOfBLASH]

I'm having a very hard time seeing how a spacecraft could NOT contain an immense amount of patented tech.

Patents expire and the devil is in the details. If your only criteria is reaching another star, eventually, well heck that mission has been done with 1970s technology, although -- spoiler alert! -- it's not scheduled for the rendesvous for another 40,000 years:

http://www.space.com/22783-voy...

My suspicion is if you were willing to travel slow enough (or endure some time debt by accelerating and decelerating slowly to the speed of light), you'd have no problems getting to another star, patent free, using apollo era technology.

Of course, if you want to build warp drives and solar sails that can be deployed maybe you'll need to license some patents. But only for some years before it becomes public domain.

Re:I think its time we hack space travel.

[Baron_Yam]

>My suspicion is if you were willing to travel slow enough (or endure some time debt by accelerating and decelerating slowly to the speed of light), you'd have no problems getting to another star, patent free, using apollo era technology.

Look up Project Orion. Nuclear pulse propulsion that can get you up to around 5% of c, and it's likely there are not a lot of patents around the idea of riding a nuclear blast wave. You'll have a lot of trouble getting the nuclear material, though. Or building the massive ship required to safely ride the shockwaves. Anyway, that would get you to the nearest star in around 80 years.

Now, a fusion rocket (which we have yet to perfect, but is scientifically feasible) could go twice as fast, and would likely come loaded with patents.

Warp drives, like the EM drive, are impossible, and solar sails aren't practical for ships large enough to sustain humans on multi-generational missions. If we could even build such ships yet, because right now you'd probably be dead within a decade due to environmental collapse if not a lot sooner.

Re:I think its time we hack space travel.

[iggymanz]

there is no apollo era tech that will get you to another star. Any starship need to use whatever is the latest and best at time of building beginning the journey, anything else would cripple the mission.

For example, fabbing own rad resistant computer chips that have the computational capability for dealing with interstellar navigation and propulsion at a significant fraction (say 5% or more) of lightspeed, that's a multi-billion dollar corporations playing field,

The propulsion will need to be novel, the best we could do at present would be something like a fission fragment engine (basically reactor spewing bits of its fuel). Something like that when invented will be chock full of patented things. Ditto any working fusion reactor which we of course don't have, full of patented things.

So will the life support systems (which don't exist yet), nothing in 1960s will be up to the task.

That's to say nothing of the materials used, which also probably will be patented

Re:I think its time we hack space travel.

[iggymanz]

Project Orion is a risky in practice, no one is going to build a craft like that with a hold containing thousands of nukes and where a misfire in the wrong time or place of any of those thousands means death for all crew. Fission fragment propulsion reactors can do the exact same job more safely, though of course if such a thing ever made reality it will be loaded with patented and proprietary tech and materials requiring the resources of many multi-billion dollar corporations to make. We're going to the stars, if we go at all, on intellectual property laws and with mega-corporate interests, get over it.

Re:What makes this special?

[Dunbal]

Hey, just because you think it's a long walk to the grocery store, doesn't make that any more of a absolute yardstick.

Tell that to a quadriplegic. The back yard may be closer than the grocery store but that still doesn't mean he's gonna get there any time soon. Without the wheelchair and a motor or someone to push, all distances greater than zero are out of reach.

Not interesting.

[Sqreater]

Just more useless busy-think as science goes down the rabbit hole of irrelevance. The scientific-industrial-complex makes sure this stuff is constantly in the news in order to justify expensive programs to the government and public.

Re:Unlikely

[Anonymous Coward]

That gravitational deflection could be caused by any nearby massive body, like yo' mama.

" if there is life there, [we will know] within a

[thinkwaitfast]

decade"

Awesome. That's sooner than we'll know if there's life on Mars

Re:The star is named Trappist-1

[wbr1]

What you did there, I see it. It has some spicy yeast esters too!

Invisible planets real, climate change false

[taniwha]

So when NASA tells us that invisible planets light years away are real we all clap, but when it tells us that climate change right here is happening some how it's all a big con?

Re:Invisible planets real, climate change false

[tomhath]

when it tells us

Data supports one but not (necessarily) the other. Fudging or hiding data is the problem.

Re:Invisible planets real, climate change false

[wvmarle]

One of these issues is hurting established business interests. The other not. That's the key difference.

Starting system

[Wolfling1]

And all the Moo players say 'Oh wow... why didn't I start in that system? Have to colonise that one first.'

Re:Unlikely

[JoeMerchant]

Oops, sorry, it was actually the civilization living _on_ the star periodically drawing excess power that made it look like 7 small planets circling it. The environment of the dwarf star being uniquely suited to formation of stable magnetic loop plasma codons which have evolved over the millenia much like our DNA to support a diverse ecosystem of creatures that live on the surface exploiting the temperature differential between the surface and space to perpetuate their growth, locomotion, reproduction and evolution.

Re:Unlikely

[xevioso]

Unlikely, but possible, I suppose.

Re:Thrilling?

[MightyMartian]

My understanding is that once the James Webb telescope is able to start analyzing the system, they may very well be able to get some atmospheric data. If we see a significant atmosphere, water vapor and oxygen, then I'd say you've come pretty damn close to confirming life.

Tidal locking question

[Michael Woodhams]

Low mass stars (and this one is very low mass) are dim, so the habitable zone is very close, so tidal effects of the star on the planet are large*, so under normal circumstances the planet will tidally lock to the star, which is not friendly to life. (Although I wouldn't go so far as to say life is impossible on a tidally locked world.)

If the planet has a large enough moon, it will lock to the moon instead, and avoid the star tidal lock (at least for a while.) So I imagine a planet and moon locked to each other and in close orbit around the star. In this case, what will happen to the planet/moon orbit as it gets perturbed by the stellar tides? Will it remain stable, or has the moon only bought me temporary reprieve from stellar tidal lock?

* Back of envelope tidal calculation:
Luminosity of star L proportional to mass of star M to 4th power (roughly)
Goldilocks orbital radius R proportional to sqrt(L), i.e. R propto M^2
Tidal strength T propto M/R^3 (it is derivative of M/R^2), so T propto M/M^6 = 1/M^5. (It is the 1/R^3 which allows a moon to out-tide the star, despite being very much less massive.)
News says this star is 2000 times fainter than the sun, so about 0.15 solar masses
So tidal effects of star on habitable planets is about 13,000 times greater than tidal effect of sun on earth.
The tidal effect of the sun on the earth are small but noticeable - it causes the difference between spring and neap tides.

They found Kerbin!

[SharpFang]

Seven planets - check.
Exceptionally compact solar system - check.
Exceptionally small star - check.

Try to check if the sixth planet is a gas giant with five moons. Or try to determine if the second planet is purple!

Re:They found Kerbin!

[Xyrus]

If they're more of them, then they're just running the Outer Planets Mod

Re:Thrilling?

[LunaticTippy]

the star is "ultra-cool"...Maybe we can send all the hipsters there?

They were there before it was cool.

Re:What does '2000 times fainter' really mean?

[Immerman]

Okay, fair enough. I agree that logically, you should be 100% correct. In practice though it seems that most people use "Nx larger" and "Nx as large" synonymously. Especially as N increases past one and beyond.

Not really relevant to "Nx smaller" though, as a similarly literal interpretation of A being "3x smaller" than B would mean that the size(A) = -2*size(B), which is nonsensical.

Also, in either case once you're talking about 2000x larger/smaller, the distinction is lost in the rounding errors.

Re:What makes this special?

[Immerman]

Umm, no.

The James Webb telescope will have a resolution of 0.1 arc-seconds, meanwhile even the closest star, Proxima Centauri, has an angular diameter of only 0.001 arc-seconds. There are larger stars, but even Betelgeuse, one of the largest as seen from Earth, is only ~0.05 arc-seconds across. So the Webb telescope won't even remotely be able to resolve an image of a star's surface, much less an exoplanet. They'll still be nothing more than single points of light.

From what I can find, it appears that the Webb will actually have roughly the same resolution as the Hubble - it's benefits will primarily be in being able to see dimmer objects, and across a wider band of the light spectrum (particularly further into the infrared). Which will allow it to better analyze the absorption spectra of the atmospheres of exoplanets, but not actually see them.

Re:What makes this special?

[0111 1110]

http://www.space.com/33840-alien-world-proxima-b-around-nearest-star-could-be-earth-like-video.html

https://en.wikipedia.org/wiki/Gliese_581

Need I continue? Is it too much work for you to take an extra 1-3 seconds to google before you make an ignorant statement like that? Actually it seems that most and perhaps even all stars have planets including rocky ones. What this really shows is the variability possible and that rocky planets are probably ubiquitous and can just be assumed to exist in most cases.

One of the most important changes I've seen in my lifetime has been this shift from pessimistically assuming that there were relatively few rocky planets in the galaxy and that many if not most stars lacked them to what we are actually seeing now: that they are in fact almost everywhere we look carefully enough to the point that it might be more useful to search for stars that don't have any rocky planets. There are plenty of systems where we haven't detected any but the absence of evidence is not the evidence of absence. Small rocky planets are very difficult to detect.

When I first saw the 40 ly figure I thought of Zeta Reticulum which Betty Hill and Marjorie Fish made famous in the 60s. Zeta Reticulum may be one of those few systems that don't have any planets at all: not even gas giants.

Another star with some mythology behind it, Sirius (made famous by the Dogons) appears to lack planets, although again it's difficult for us to be sure of that. We have looked though.

Re:Thrilling?

[0111 1110]

Finding that many Earth-sized rocky bodies orbiting a star just 39 lightyears away, with the possibility that some of them may be able to have liquid water on their surface doesn't excite you?

It seems that nearby rocky exoplanets are all over the place so no this doesn't get me all that excited except as more evidence that many or even most stars have them. Gliese 581 is half the distance and even our companion system Proxima Centauri probably has one or more of them.

This does not mean that it isn't worth sending them an RF or laser message though to see if we get a reply in 80 years because well you never know. Although there are certainly more compelling targets in a 40 ly radius.

Re:Thrilling?

[Scarletdown]

Perhaps R&D into interstellar exploration will get a tremendous boost thanks to the same thing that made home video and the Internet big commercial successes...the porn industry. (Giggity)

Re:Unlikely

[Boronx]

Inference *is* questionable. We just don't have anything better.

Re:Unlikely

[Scarletdown]

If they really wanted to troll us, they would craft the Orion Nebula into the Goatse Nebula.

Tidal locking? Sign me up!

[TiggertheMad]

Tidal locking would be GREAT for developing life. Having a constant source of light/warmth is wonderful for a lot of types of life. Sure, there wouldn't be a photosynthetic life developing on the dark side of the planet, but could you imagine the abundance of life that might grow on the light side of the planet? Imagine a planet with a constant, never ending spring or summer. Of course the actual orbit would likely alter the temperature seasonally, but 24/7 (relatively speaking) light would be fantastic for life.

Re:Thrilling?

[stealth_finger]

Finding that many Earth-sized rocky bodies orbiting a star just 39 lightyears away, with the possibility that some of them may be able to have liquid water on their surface doesn't excite you? Did you have your sense of wonder and curiosity surgically removed?

It's interesting to be sure but far from thrilling (to me), it's kinda non news. Until we put any appreciative effort into actual space travel they might as well be in Andromeda. Hell, can we even actually see them or just 'detect' them? Give me a shout when we pick up radio waves from there or get a picture of one or more of the planets with lights on the darkside. Now that would be more thrilling than there's a star with a bunch of large rocky bodies relatively close in a galactic sense but still an unfathomable distance away.

Re:That quote can't be right.

[mbkennel]

All else being equal, the surface temperatures in Kelvin will go as the fourth root of the flux, because emissivity is proportional to T^4 and you presume that outgo = incoming energy in rough equilibrium. So temperatures in Kelvin varying by 2.3, which is still a huge difference but not 30.

Re:Unlikely

[DarenN]

What do you think "black holes" are?

Caprica, or the Xindi?

[wolverine1999]

Caprica, or the Xindi's homeworlds?

Re:Unlikely

[coofercat]

One thing I've always wondered about this method is... isn't it rather convenient that these planets orbital plane is exactly right for this to work? I mean, surely there must be an infinite number of possible orbital planes, and indeed the possibility that there are planets that aren't on their neighbouring plane at all.

I'm sure I didn't just discover the Great Flaw in all of astrophysics, so I guess there's an explanation somewhere...

Radiation?

[sycodon]

Being so close to their star, wouldn't radiation be a huge issue?

Re:Radiation?

[Immerman]

As AC said, not necessarily for things evolved to survive in it. Tardigrades for example can handle fairly large doses just fine.

The planets are also likely tidally locked, and solar radiation would be a complete non-issue for anything on the dark side of the planet. Life has no need for light after all, it had been thriving on Earth for millions of years before the first bacteria evolved a light-sensitive protein that let them detect daylight and flee to deeper, safer water. And many millions of years more before one evolved the ability to harness light for energy.

Re:The star is named Trappist-1

[stud9920]

Chimay be right, chimay be crazy..

Way beyond the Rochefort limit

Re:What makes this special?

[bobbied]

Seriously? Very sorry I wasn't precise enough for you...

These are the closest possibly habitable planets they have found to date and likely none will be closer. What part of this did you not get?

It's not like there are *that* many stars within 30 light years or so..

Re:What makes this special?

[Immerman]

We're talking about space science - "someday" is usually presumed to be many decades or centuries in the future.

And is that all? Really? That's not too bad. Child's play once we get serious about astronomy and start building gravitational telescopes using our sun as the lens. What could you resolve with a 550-700AU focal length?

Re:Thrilling?

[syntotic]

It is the age. NASA is not precisely an internet, web page, company, though it still works artisanally, so, who will care?

Re:What makes this special?

[0111 1110]

You did not even click on my links, did you? Damn Millennials. Why are you so lazy? You have a great Oracle that our generation never had. We had to go to a fucking library or call a university professor or something and all you have to do is type a keyword and hit enter but you cannot be bothered. Incidentally in this post you have made even more easily checkable errors. Slashdot has really gone to shit.