Earth and Moon From an Alien's Perspective 150
krygny writes "NASA's Deep Impact spacecraft (whose extended mission is called EPOXI) has created a video of the moon transiting Earth as seen from 31 million miles away. Scientists are using the video to develop techniques to study alien worlds. 'Our video shows some specific features that are important for observations of Earth-like planets orbiting other stars,' said Drake Deming of NASA's Goddard Space Flight Center... 'A "sun glint'" can be seen in the movie, caused by light reflected from Earth's oceans, and similar glints to be observed from extrasolar planets could indicate alien oceans. Also, we used infrared light instead of the normal red light to make the color composite images, and that makes the land masses much more visible.'" Here are links to the two videos, one red-green-blue and the other infrared-green-blue.
Missing something (Score:5, Insightful)
Perhaps I am, but 31,000,000 miles doesn't seem that far away from an astronomical perspective - in fact it seems pretty darn close. A single light-year is about 5,878,625,373,183.61 miles (from Wiki), so 31M miles is roughly 1/190,000 of a light year.
The nearest star is ~4.2 light years away, so our potential alien visitor would have to travel a very long way towards us (and in that case why not come the last 0.0001% of the journey!) before this was a useful property.
Now I realise you can only take a video from as far away as your spacecraft really is, but I'd expect to see extrapolations to realistic distances before you start to claim things like "Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe". - that's a bold claim, after all. I'm sure there's a standard line somewhere about extraordinary claims requiring extraordinary evidence to back them up...
I dunno, perhaps I'm just a grumpy old physicist, but there's all sorts of effects that only come into play at astonomical-scale distances (and the relativistic-scale speeds that commonly occurs between bodies that far apart), I guess I'd like to have seen more data and less hand-waving.
Simon.
Re:Missing something (Score:5, Interesting)
Space is largely empty so you can turn off most things and just leave your spaceship alone for the majority of the journey. A few microcalibrations along the way will see you right. Taking off is a lot harder but it's the sort of thing you can practise a lot too so you should be ok with that as well.
Doing something in the alien environment at the other end though, such as a solar system or a planet ... that's really hard. You have to design your craft to be able to deal with thousands of unknown, or known-at-an-extreme-distance, factors. That could well put a travelling alien off coming the last 0.0001% of the journey.
Re:Missing something (Score:5, Interesting)
I'm sorry, I think you're underestimating the survival problems imposed by such vast distances...
A gedanken experiment: Assuming you're right, and the distance isn't that much of a problem, *we* have launched spacecraft which have travelled to and landed on different (far closer) planet(oid)s, I have difficulty believing an alien civilisation that can navigate the truly immense gulf between planetary systems having any difficulty at all with a landing or navigation of a solar system (which is also pretty empty, btw)
You do get to make a billion or so observations of the destination as you're travelling towards it, after all. It's not going to be a complete unknown or anything...
Simon
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I'm sorry, I think you're underestimating the survival problems imposed by such vast distances...
Assuming the aliens are not capable of exceeding the speed of light, then yes, definitely. No matter what the average lifespan of various alien species might be, I'd have a hard time imagining a species that lives for hundreds of thousands or millions of years, definitely. Even if you consider a multigenerational spacecraft, where its occupants spawn off succeeding generations, the sustainability of something like that in the confines of spaceship, even if it were the size of a football field, just doesn'
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If you get close enough to lightspeed your time slows down so it becomes feasible to live through the journey. The hard part is the acceleration and deceleration (even if you can produce the necessary thrust you have to consider the maximum force the crew can survive vs the time needed to accelerate at that force). I think once SciFi implementation of regular travel with time dilation has been used in Soukou no Strain (anime), a central theme was the time that passed while the spaceships were travelling at
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Using simple, non-relativistic math, you would surpass the speed of light by accelerating at a constant 9.8m/sec in just under a year. That means you get to live on your spaceship with simulated earth gravity due to your constant acceleration. That means we don't need to turn the inside of our spaceships into pink goo to accelerate to relativistic speeds within a reasonable amount of time.
The only problem is fuel. How do you power a ship at 9.8m/s^2, or any other 'sizable' acceleration? for that long? And d
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You would be right except relativity is an important factor and cannot be simply excluded. Your example makes the assumption that there are no relativistic effects, which is not correct, hence your conclusion is way off too. D-
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You would be right except relativity is an important factor and cannot be simply excluded. Your example makes the assumption that there are no relativistic effects, which is not correct, hence your conclusion is way off too. D-
Relativity is pretty weak up to very close to c. Even at 98% of light speed, the Lorentz factor (mass increase, time dilation, etc.) is only somewhere around 5. So, allowing for a decent fudge factor, classical physics isn't a half bad assumption.
So, making it to such speeds is not extremely unfeasible (fuel required would be around the same order of magnitude and such). The trade off is really the amount of fuel required to attain a certain speed, and the benefits in terms of time dilation you get.
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Using simple, non-relativistic math, you would surpass the speed of light by accelerating at a constant 9.8m/sec in just under a year. That means you get to live on your spaceship with simulated earth gravity due to your constant acceleration. That means we don't need to turn the inside of our spaceships into pink goo to accelerate to relativistic speeds within a reasonable amount of time.
The only problem is fuel. How do you power a ship at 9.8m/s^2, or any other 'sizable' acceleration? for that long? And don't forget you also have to slow down, or you won't enter orbit around your target--although in the case of New Horizons, it's designed to blow by Pluto because it's not feasible to conduct a mission that *eventually* puts a probe into orbit around the minor pluplanetoid.
Another problem is the means of propulsion. Rockets are good for steering, but not for achieving huge speeds. The speed attained from a rocket is LOGARITHMICALLY proportional to the mass of fuel (hence multistage rockets, every mass reduction helps). They may work to escape earth's gravity, or even get to the moon and back, but it won't get you near the speed of light.
Unfortunately, the options are pretty bleak. Ion thrusters as well as solar sails are so slow it's simply not feasible for a manned expediti
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Assuming any sort of sensible and ordered interstellar exploration, and not some sort of, "Our sun's about to go supernova, we need out, NOW!" situation, the aliens will *know* where they're going. Long before, they would have launched robot explorers, using techniques not acceptable for life. I'm thinking railguns if they're in a hurry, ion engines or solar sails if they're not. There would already be quite a network out there in our solar system studying things, beginning in the Oort and moving inward a
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you suggest nano-tech, and frankly a self-repairing robot with nanotech is the only way for a machine to survive for hundreds of years let alone millions, or billions. the problem is metal whiskers, even lead, although lead whiskers are rare, tin is the worst offender... and this is within human life spans... without constant nanotech repairing all the robotic and data processing parts, while recycling end of life cycle nanobots, is the only way a machine can last that long, even if it's not being used...
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Like I said, if "They" are out there, they're more likely taking bets on exactly how we're going to finish ourselves off, with a few taking the long position that we'll actually make it.
As for whiskers, you've just made some technological assumptions, the big one being some form of soldering. The truth is we know very little about reliability out past 100k or 200k POH. We don't design past there, we don't develop technologies past there. We've never even tried, so IMHO if we were to really try, I think w
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But your craft was designed and launched without the benefit of those billion (relatively close-up) observations. So any adjustments based on them need to be possible based what you already packed for your trip.
Let's say I want to go on a pic-a-nic and do not pack a gun because it is too heavy. Then, as I get closer to my most favorite pic-
why make such incredible assumption (Score:2)
Why not go with the simplest explanation. First of all space is vast and huge with limitless possibilities both bad and good. Thus assuming there is some alien society capable of navigating the great reaches to meet us is a pretty big assumption why not make it simple.
I simple society that does not share in our challenges. Lets say a biologic that reproduces asexually, and has long gestation periods. A simple cocoon cable of reflecting harmful radiation catapulted from there home asteroid which has limited
Missing something, no sound or music ! (Score:2)
Here you go, grumpy old man ; )
http://www.youtube.com/v/AFks9A9TCF0&hl=en&fs=1 [youtube.com]
This Might be the First Time Ever (Score:1, Offtopic)
That a YouToob video got /.ed
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Yeah, it does seem to be a little useless.
I mean, we're talking less than the distance from here to the sun (93 million miles).
Maybe this will be useful for determining if Mars has giant oceans on it.
Re:Missing something (Score:5, Insightful)
Nonetheless, this distance is a new data point - that much is for certain. Even A single data point can really illuminate a function.
2, 4, 8, 16 means something completely different than 2, 4, 8, 32, after all.
Still, I do agree that the claim does sound a bit inflated.
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4, 8, 15, 16, 23 and 42 are better numbers IMO.
Re:Missing something (Score:5, Interesting)
You can't resolve objects at the separation of the moon and earth from 30 trillion miles away, not even with the Hubble or Keck telescopes, and especially not with spectroscopes that can give you clues to what chemicals are present on those bodies. By studying star wobbles an astronomer might infer the presence and mass of a "planet," but that won't tell him if it's really a single planet or a planet-moon system. Look at the video and notice that as the moon crosses the earth, the total reflected light from the earth and moon would be decreased by the ratio of the area covered (about 7%) because the moon is blocking part of it. From that, the astronomer can infer not just the presence of the moon, but the relative sizes of the planet and moon.
Assuming the Space Interferometry Mission goes forward as planned, the astronomer might eventually be able to get a spectrum from the planet without being washed out by the parent star. By watching how the spectrum changes during such transits, they can figure out what elements and compounds (like water) are likely present on the planet, and what ones are present on the moon.
It may sound far out, but it's already being done with exoplanets and their stars, and transits of Pluto and it's moon are how we got a lot of our information so far about those two bodies.
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You can't resolve objects at the separation of the moon and earth from 30 trillion miles away. ... By studying star wobbles an astronomer might infer the presence and mass of a "planet," but that won't tell him if it's really a single planet or a planet-moon system.
Sure you can. There is a lot more information in one pixel than meets the eye. That one pixel of a star can show you the size, mass, and semi-major axis of a planet (though current technology is only sensitive enough to be able to detect large
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I'm sure there's a standard line somewhere about extraordinary claims requiring extraordinary evidence to back them up...
True, though from a scientific perspective it ought to be retired in favour of 'All claims require adequate support for provisional acceptance'.
But your main point is well made. 31M miles is woefully inadequate to suggest that this will be useful in looking for earth like planets in other solar systems. It might be of use to Hollywood looking for a realistic depiction of what earth would look like on approach by a spacecraft from a distance of 31M.
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They wouldn't bother - they'd just make it up like they do with the rest of science. And history.
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I'd expect to see extrapolations to realistic distances before you start to claim things like "Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe". - that's a bold claim, after all.
That's not a remotely bold claim. Variations in brightness and spectrum from the sun glint and the Moon's transit of Earth should be similar to that seen any virtually any distance. I think that the article's scope went over your head a bit - it's assumed that the reader understands that any extra-solar planets in an image will be contained in a single pixel.
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Hmm. PhD in Physics. Not *too* far over my head, I think. I can always be wrong (astrophysics wasn't my specialty), but I actually think it *is* a bold claim. When you extrapolate (note, not interpolate) *anything* by several orders of magnitude, you better be sure of your deductions.
Radiant energy intensity falls off with the square of the distance. Variation within that intensity therefore falls off at the same rate, and is consequently harder to detect above the noise threshold - with the relative distan
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Argh, typo. That should be "metric expansion of space", not "space time" or even "spacetime".
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They aren't making any bold claims.
They are saying that studying the images of earth close up where they can see details, may help them develop techniques to obtain information from the varying light intensity of the spot. Because that's all they'd really be able to see of an alien world. A spot of light whose intensity varies as land masses and oceans pass into view.
The video clips from the images, made my heart flutter...
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Most definitely. It's a pleasant start, and definitely one of the best we've got to work with at the moment, but it falls quite flat, I feel. The Pale Blue Dot [wikipedia.org] is far better - just wish we had the tech then to do the observation here.
Hang the "all sorts of effects," that's just icing - shit is just small! The Earth-Moon system is pretty easy to observe when you're around it, but 4 billion miles away, a single dot ain't much to shake a stick at. Now, as you stated, the nearest star is over 6200 times far
Beautiful (Score:5, Interesting)
I wish Sagan could be here to see this.
Re:Beautiful (Score:5, Insightful)
Actually, no, I don't. I think if Sagan was miraculously reconstituted today, he would take one look at the shape of our Education System and of the Sciences and Space Program in the States and he would die of shock and sadness.
Re:Beautiful (Score:4, Interesting)
I think if Sagan was miraculously reconstituted today, he would take one look at the shape of our Education System and of the Sciences and Space Program in the States and he would die of shock and sadness.
He only died in 1996. You think things have changed much in 12 years?
As far as Space goes, there are actually some encouraging signs, much more than 12 years ago. The shuttle is finally being put in the shitcan like the unbelievably wasteful pile junk it is, we have several landers on other planets, and private industry (finally) looks like it might produce some interesting private space trips.
Unless your sole metric for success is government largess, space is much healthier than it was 12 years ago.
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You think things have changed much in 12 years?
Yes. They've gotten much worse.
private industry (finally) looks like it might produce some interesting private space trips.
Maybe. So far everything is being done in the interests of space tourism. I'd like to see private industry strive to do something useful.
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Maybe. So far everything is being done in the interests of space tourism. I'd like to see private industry strive to do something useful.
Useful? If you don't like tourism, private industry already puts satellites in orbit.
But I would say Tourism is by far the most useful thing we could be doing right now. That puts direct downward cost pressure on putting people in space for as little money as possible. The biggest holdup in whatever your definition of "useful" is, is the cost to put payload in space. If
Re:Beautiful (Score:4, Informative)
>>You think things have changed much in 12 years?
>Yes. They've gotten much worse.
Maybe the big picture is worse, but I note that incoming freshmen at the university where I work, are
coming in quite strong with physics, chemistry, calculus, writing, and most even have good placement in
a second language. My local, small, unscientific sample indicates a strong high school system, turning
out students who are as well-prepared for university as we could ask for.
Are you seeing different results among graduating seniors?
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but I note that incoming freshmen at the university where I work, are coming in quite strong with physics, chemistry, calculus, writing, and most even have good placement in a second language
Are you sure that they are not coming from outside the United States (Europe, Russia, India, China etc)? They sound like an exact description of the well prepared and intelligent students that are frequently attracted to American universities from abroad.
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So the blanket criticism that assumes the US public school system is somehow fundamentally flawed, needs to be resolved with the fact that students *do* exit these schools very well educated, despite those flaws.
How can we be certain that some percentage of the high school students, the top 10% say, are no succeeding in spite of our educational system and not because of it? There will always be self motivated and intelligent students who basically see to their own needs as long as they are not actively opposed in their efforts by exceptionally incompetent teachers (yes, they are out there) and school administrators. The fact that a large number of well qualified American students are admitted to American universiti
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Well, you can be certain that you're thesis is correct. There are always students who succeed "desp
Re:Beautiful (Score:4, Insightful)
Facts have no bearing on these kinds of opinions. There are people for whom things are always worse, as current situations are constantly compared to an idealized past that never actually existed.
Such people get joy out of believing that they are the last of some special breed of amazing people, never to be seen again. It's just part of the human condition.
It deserves pity, but not recognition or respect.
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As do I... I feel so melancholy thinking of the absence of Douglas Adams, Asimov, Clarke and the like as these amazing things come to be.
After a deep sigh I try to pep-up by imagining that they would be happy that at least we are here to see it.
I think to myself that although I probably won't be here to see interstellar travel, but if humanity does make it to the stars then I know I would have been happy that we did.
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Actually, if Sagan were to come back to life, he'd say: "Hey, never mind that cr*p! You atheists, get over here and huddle up! I've got some REALLY URGENT NEWS for ya...!"
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I don't think there are intelligent enough brains left on earth to slake the thirst for knowledge that would possess a Zombie Sagan.
At least, we can only pray.
Wow (Score:5, Insightful)
Watch Sunshine! (Score:2)
Go watch Sunshine [imdb.com], that movie definitely evoked those same kind of feelings in me.
There's an amazing scene where they watch Mercury transit across the Sun, and while we admittedly have the same view from here on Earth, imagining those folks were really on their way to the heart of the solar system, with one last, tiny gatekeeper between them and the monster that is the Sun is just AWESOME.
Goose-bump city.
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What really kicks up the awe is just how loud sunlight is when you get close...
That was the stupidest movie since Red Planet [imdb.com].
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Sound is a pressure wave...so yeah, it is loud near the Sun. This was discussed on The Universe (History Channel).
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That was the stupidest movie since Red Planet [imdb.com].
http://www.sci-fi-online.50megs.com/2006_Interviews/07-08-27_brian-cox.htm [50megs.com]
http://en.wikipedia.org/wiki/Brian_Cox_(physicist) [wikipedia.org]
"I've discovered this whole new set of people - science fan boys - that I didn't know existed, really. They're interesting. Their almost fundamentalists, in a way. They are much more pedantic than professional scientists. I just interact with professional scientists most of the time and I must say, I've said this a couple of times now, but I've found the scientists that I like to work
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Holy cow, it's Uwe Boll imitating Buckaroo Banzai. That explains everything.
The problem with the film isn't the ridiculous number of creative liberties taken with physics. It's the fact that of all the highly qualified, professional people who would undoubtedly volunteer in droves to save the world, the crew is made up of a bunch of unstable, narcissistic emo whiners, and the ship is designed in such a way to give them endless opportunities to fail. It's a slow horror movie, and like all bad horror movies,
Relative albedo of earth and moon (Score:3, Interesting)
When we look up at the moon, it moon looks like a pretty bright, reflective object. But in images containing both the earth and moon, you can see that the moon looks positively dim and dingy compared to the cloud-covered portions of Earth.
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Yes, I first realized this when I saw a sample of moon rock at the Smithsonian. It's almost black.
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I actually WTFV, too. The moon swung around in an orbit nearly on a plane with the observer and continued merrily on its way. Given that the sun also appeared to be even with the observer, shouldn't that have caused a shadow (lunar eclipse) on the Earth?
(Insert obligatory Patsy quote: "It's only a model.")
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Total Sola [nasa.gov]
Cool, but then again.... (Score:5, Funny)
That's cool but then again, I'm a sucker for any movie I'm actually in.
Hey.. (Score:5, Funny)
Habitable planets must have large moons? (Score:4, Interesting)
Huh? Did he just say that habitable planets must have large moons? (I've heard a similar argument before - something about two widely spaced bodies keeping the big one from wobbling too much.)
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The transit of the moon isn't the most important thing in the animation. That you can see the forests on the continents in near-IR is hugely significant.
Yeah, that was impressive. The forests really light up on IR.
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Well as far as I understand, the theory is that a single large moon keep the earth's tilt relatively constant. In simulations, if the large moon is not present, it varies wildly anywhere from 0 to 90 degrees.
The expected result of this would be no "perminant" ice caps on the poles since they would be exposed more directly to the sun just as much as any other part of the planet. Net result... Higher oceans constantly, and much more erratic weather patterns.
Some believe that life would have evolved anyway, bu
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The Earth got its tilt due to a Mars-sized object colliding with the Earth way back and creating the moon from debris. Had there been no such collision, there would be neither a moon nor tilt. A tilt of 0 wouldn't precess. The other rocky plants have either no moons (or no moons of gravitational co
Cosmic Tilt-A-Whirl (Score:2)
Not correct.
First off, given the currently understood process by which planetary systems form, giant collisions are inevitable. There isn't a single non-tidally locked planetary body in the solar system that doesn't have an axis tilted relative to the ecliptic (even Jupiter!) In fact, as the Jupiter example shows, it's not obvious that a body, even during the accretion phase, will end up with zero tilt. As mass accretes to a growing planetoid, it's unlikely that all of the angular momentum of the impacting
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I've also heard 2 other ideas about a large moon, plus 1 science-fiction one:
1: Take a rocky planet that formed with a dense atmosphere, and a large moon helps draw some of the primordial atmosphere away, as things are forming. Supposedly this is one of the factors helping the Earth to not look like Venus.
2: Tide pools - a big assist/push in getting life out of the water and onto land. For that matter, tide pools might have been a key ingredient in life itself, separating small "experiments" from the pre-
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maybe not absolutely needed but it has certanily helped [astrobio.net] us [damninteresting.com] here
Mostly... (Score:4, Funny)
...harmless
That's no moon... (Score:5, Funny)
Insignficance (Score:1)
The world keeps spinning, doing what it's doing, no matter what you do. We're all just bacteria on the proverbial fruit.
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A video like that really helps you realize how small and insignificant you really are.
On the contrary, if you accept what the Fermi Paradox implies, it shows how unbelievably special, improbable and unique we are in the entire galaxy, if not the entire Universe. [personally, I suspect intelligent life is so improbable that it takes 2.55e35 cycles of the universe(s) for it to happen, on the average.]
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What amazes me is that (independently) self-reproducing lifeforms even exist at all, given that the simplest known one has over 500K base pairs. I recently posted [slashdot.org] about this. From what I can
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There seems to be a flawed assumption underlying the Fermi Paradox, namely, that intelligent life will invariably make a concerted effort to contact other intelligent life on other planets.
What makes the Fermi Paradox so powerful is it only takes one. It only takes one civilization creating a sublight self-reproducing probe to geometrically fill a galaxy in around 1-10 million years, a blip in the history of the galaxy. Or, using sleep ships, a civilization could fill the galaxy in around the same amount
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I don't know what the practical limit on distance would be, but even if I were to assume that you could traverse several hundred light years, you would still be talking about only a few hundred or thousand stars within your reach, not billions.
Think geometric expansion. Once they reach one star system and establish a colony, then eventually they'll get another set of group(s) that goes off from there. Even if it took 100 million years to fill the galaxy, odds are it would've happened a long time ago -- if
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Also, as soon as you're a part of some system, the system is never the same as it would be without you. And you can't even observe a system without being a part of it and having an impact on it.
The buble must burst. (Score:2, Insightful)
Yup, but to me (and damn near 100% of everyone else), you're really close to nothing. Outside of this planet, you're even closer to nothing.
Hence, insignificance.
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Or reversing this "we're insignificant" way of thinking - what kind of impact has on you some random supernova that happened half a million light years away from here, half a million years
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Is it just me, but when looking the infrared video, it seems like europe is radiating heat like nothing else.
Actually, I found it much more fascinating to note the color differences between hot and cool regions. In the infrared-green-blue video, notice the bright orange color of central Australia, the Arabian peninsula and the Sahara region of northern Africa. This rather puts the other color regions (which often are such a dark red to almost be black) in perspective.
And for those that decry that the distance seems much too close to be useful, I would like you to remember that this is more for the purpose of imp
Because real reality isn't real enough... (Score:5, Funny)
Also, we used infrared light instead of the normal red light to make the color composite images, and that makes the land masses much more visible.
Sigh...everything's gotta be special effects these days...
FMV version? (Score:2)
Anyone got FMV versions of these videos? I don't have Quicktime installed on my work (Windows) laptop, and would rather not jump through all those hoops just to view what sounds like an interesting vid.
(Alternatively, I can wait until I get home from work and use Gplayer.)
Above average? At that distance? (Score:1)
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We are not able to resolve images of extrasolar planets directly at all. Our detection of such planets relies mostly on orbital perturbations of stars from large gas giants and gravitational microlensing [wikipedia.org] in addition to a few other more esoteric methods that can be found at that wiki entry. We are hoping that with some new ambitious space based imaging we might be able to image one of the closer extrasolar planets like Epsilon Eridani b [wikipedia.org]. Although that is a Jupiter sized planet. I'm not sure what kind of tech
Earth/Moon Model Screensaver? (Score:2)
Is there a GNOME (Ubuntu) screensaver that shows a realistic model (in scale, accurate surfaces) of the Earth and Moon orbiting each other?
I'd like to see our system from an alien's perspective whenever I've stopped working for a few minutes. Really give me the feeling of being "away from my desk".
My favorite space pic - Sunset on Mars (Score:2)
Extrasolar planet visibility (Score:2)
I'm confused about how seeing the Moon transit Earth is relevant to extrasolar planetary observation. I thought that we were detecting extrasolar planets by tracking the wobble they induce in their star, not by direct observation of light reflected from the planet. If so, then how will dimming of the planet by a transiting moon be observable?
I thought the cutting edge in astronomy was the idea of a giant space telescope that might directly observe superjovian gas planets, not Earth-like planets.
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I'm confused about how seeing the Moon transit Earth is relevant to extrasolar planetary observation. I thought that we were detecting extrasolar planets by tracking the wobble they induce in their star, not by direct observation of light reflected from the planet. If so, then how will dimming of the planet by a transiting moon be observable?
The wobble is the old, established method. We need more methods to find planets, but we also want to know what those planets are like. Signs of water, life, etc. We want to know what clouds, oceans and forests look like from a distance. This video shows us that forests show up very well on IR, and that's interesting.
I thought the cutting edge in astronomy was the idea of a giant space telescope that might directly observe superjovian gas planets, not Earth-like planets.
Sure, but wouldn't you rather be able to observe earth-like planets?
Alien POV (Score:2)
Oceans? We though you had covered 70% of your planet with blue tarps.
Definitely a low class neighborhood. Move along now.
A word from the EPOXI team (Score:5, Informative)
Makes you feel small doesn't it... (Score:2)
mind you, it's a bit of a shock to see just how dark and brown the moon really is... we're dazzled by it and it looks so bright against the night sky...
There's a typo in the headline (Score:2)
There, that's better :)
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The importance isn't the image itself. It's how the image changes with time, including the rotation of the earth changes the reflected light and the position of the moon.
There are certain things we can guess, but in trying to build a model of how to observe other Earth-like planets from a distance, an actual observation, even from a much shorter distance, can improve the technology many times over.
In the end, when we look for extra-solar planets, we aren't looking for pretty images, we're looking for funny
Re:*.MOV - WTF? (Score:4, Informative)
.mov is QuickTime, which is old and not proprietary; I have a book here describing the format. However, that's just the container format; it's the codecs commonly used within QT these days that are proprietary.
And according to mplayer, the codecs used here are mp4v for video, and aac for audio. In other words, (tada!) MPEG.
Fsck all of you. (Score:2)
I can't open the thing in Windows Media Player, I can't open it in Real Player, and Digital Media Converter is telling me that I have to install Quacktime before it will convert the thing.
And I fscking refuse to install Quacktime.
FSCK THIS SHIZNAT.
AND FSCK THESE TAX-PAYER SUBSIDIZED, STEVE-JOBS'S-@$$-KISSING C*CKSUCKERS WHO ENCODE TO THIS PROPRIETARY SHIZNAT.
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MPEG non-proprietary?
MPEG2 maybe, but only because the patents have died.
Think before you post.
Re:Viewable videos (Score:4, Informative)
VLC will play them.
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VLC will play them.
How is this informative? VLC will play anything. Everybody knows that. Right?
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I'll have to try that. Still doesn't excuse NASA for using proprietary formats.
As if .mov isn't bad enough, there are also .wmv links at the bottom.
What if in 20 years these codecs aren't available anymore due to architecture/etc?
Codecs aren't an issue anymore now that we have VLC. As long as still VLC exists in 20 years, we can watch it. But you're absolutely right ofcourse. They should have used an open standard.
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As ScienceTim points out below, the moon's orbital plane is *close to* the ecliptic, but the two are not the same. If it were, we'd have a solar eclipse every (lunar) month!
--another Tim
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It could have originated with a equatorial orbit. But over millions of years, the ecliptic gravitational tug would have pulled it into more of an ecliptic orbit.
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