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Earth and Moon From an Alien's Perspective

Posted by kdawson on from the long-look-back dept.

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.

123 of 150 comments (clear)

  1. Missing something by Space+cowboy · · 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.

    --
    Physicists get Hadrons!
    1. Re:Missing something by onion2k · · Score: 4, Interesting

      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!)

      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.

      --
      http://twitter.com/onion2k
    2. Re:Missing something by SBacks · · Score: 1

      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.

    3. Re:Missing something by Space+cowboy · · Score: 4, 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

      --
      Physicists get Hadrons!
    4. Re:Missing something by TheLazySci-FiAuthor · · Score: 4, 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.

      --
      Read my Very Short "Stories"
    5. Re:Missing something by iamlucky13 · · Score: 5, Interesting

      You're correct that the distances are wildly different, but for some observation techniques that really doesn't matter much. The distance between the earth and the moon compared to the distance to the spacecraft is small enough to be just as negligible. There's no reason why something that works 30 million miles away shouldn't work 30 trillion miles away. The only real differences are the brightness and resolution (well...perhaps some of the spectrum may be reduced by the interstellar medium, but that's a pretty specific factor).

      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.

    6. Re:Missing something by Atari400 · · Score: 1

      An advanced, non-FTL traveling, alien civilization is most likely going to put very good telescopes around their own star, at the solar foci, before they send probes to other stars.

      --
      IBM doesn't play chess with the Universe.
    7. Re:Missing something by morgan_greywolf · · Score: 1

      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't seem all that likely.

      OTOH, science fiction writers have dreamed of things more bizarre, and has someone once said, it seems that life imitates art.

      --
      My blog
    8. Re:Missing something by Anonymous Coward · · Score: 1, Informative

      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 planets orbiting very closely to their stars). What you do is observe how the star wobbles about its center of mass due to a planet (via redshift) and if the planet transits across the star. These same techniques could be used with a planet with a moon if you could see it. One pixel is enough.

    9. Re:Missing something by KDR_11k · · Score: 3, Interesting

      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 near lightspeed though the implementation of physics wasn't that consistent IIRC.

      --
      Justice is the sheep getting arrested while an impartial judge declares the vote void.
    10. Re:Missing something by D+Ninja · · Score: 1

      4, 8, 15, 16, 23 and 42 are better numbers IMO.

    11. Re:Missing something by Red+Flayer · · Score: 1

      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...

      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-a-nic spot, I see a large animal at the picnic table. I want to know what kind of animal it is, but my eyesight is not so good. What do I do? Do I approach, not knowing if it's an angry bear? Or do I maintain my distance and try to make better observations of the animal? What happens if I get too close and the bear notices me? I didn't pack my gun, so I'd rather try to determine whether it's a bear or a really hairy guy in a brown coat *before* I get closer.

      At any rate, I think it's a fallacy to assume that a race technologically advanced enough to get here would *want* to get close to a potenitally inhabited planet on a first pass... and I also think it's a fallacy to assume that they would have the capability to do so. For all we know, their propulsion technology may depend on maintaining a certain velocity with respect to the closest star... we just don't know, and so cannot make blanket assumptions about their capabilities and, more importantly, their desires for such a long trip.

      --
      "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
    12. Re:Missing something by fyoder · · Score: 1

      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.

      --
      Loose lips lose spit.
    13. Re:Missing something by Kagura · · Score: 2, Interesting

      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.

    14. Re:Missing something by halsver · · Score: 1

      "There is a lot more information in one pixel than meets the eye."

      Pixels, unlike atoms have a well defined finite amount of information in them. Now a small group of pixels ...

      --
      Roughly half my comments are never submitted. You may be reading the better half...
    15. Re:Missing something by jschen · · Score: 1

      31 million miles isn't hugely far, but we've got to start somewhere in the search for alien life. Testing ideas at short distances on an object known to harbor life (and presumably also on other objects not known to harbor life) makes perfect sense. This is from much farther away than the seminal "A search for life on Earth from the Galileo spacecraft" performed in a Dec 1990 flyby and published by Carl Sagan and coworkers in Nature in 1993, vol 365, p 715.

    16. Re:Missing something by Colonel+Korn · · Score: 1

      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.

      --
      "I zero-index my hamsters" - Willtor (147206)
    17. Re:Missing something by misterjava66 · · Score: 1

      We have pictures of the moon transiting the earth from 31M miles.
      Galaticly, Intersolarly(sic), or even on solar distance scales, yes that is a short distance.

      BUT!

      That is a farther and better picture than any other such picture we have.
      So, if you are clever, you might be able to figure out something new about
      what this would look like at 31parsecs that no one was considering before.

      MAYBE

    18. Re:Missing something by dpilot · · Score: 1

      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 as they learned more. They'd also have enough nanotech to be building new capabilities out of local materials as suitable ones were discovered.

      Assuming post-singularity, the aliens might *be* the robots. There might be a thriving alien civilization out in our solar system, staying just beyond our reach, studying us. Who knows, we might be the minority life forms in our own solar system. If life is rare, there might be representatives of several civilizations looking at Earth, studying us, taking bets on whether we make contact, or take ourselves out, or maybe taking bets on whether war, environmental degradation, or crumbling civilization takes us out.

      --
      The living have better things to do than to continue hating the dead.
    19. Re:Missing something by Anonymous Coward · · Score: 1, Insightful

      You're thinking only 2 or 3 dimensions, but what you're describing is 4 dimensions. I'll give you a hint: you're talking about a lot more than 1 pixel there, and what you're describing overlaps what I was.

    20. Re:Missing something by Space+cowboy · · Score: 2, Informative

      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 distances we're talking about here, that noise threshold is looking scarily close...

      Let's say there's a civilisation on Gamma Cephei (about 50 light years distant). Even if we just take into account the inverse-square law, the signal:noise ratio on Gamma Cephei is 27,808,132,115 *times* worse than the (already poor) signal:noise ratio of the reported experiment. Now toss in scattering due to space-born dust/whatever, red-shift effects, any interference effects, any gravitational effects, and it starts to look just a *little* bit harder, don't you think ?

      Simon

      --
      Physicists get Hadrons!
    21. Re:Missing something by Anonymous Coward · · Score: 2, Insightful

      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-

    22. Re:Missing something by Eudial · · Score: 2, Interesting

      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.

      --
      GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
    23. Re:Missing something by s4ltyd0g · · Score: 1

      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...

    24. Re:Missing something by Amorymeltzer · · Score: 1

      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 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 farther away than that picture was taken at. I'm glad they're thinking right in the head, but this is like holding a magnifying glass up to my cat in order to better understand her cells' mitotic divisions.

      --
      I live in constant fear of the Coming of the Red Spiders.
    25. Re:Missing something by kesuki · · Score: 1

      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... but this ups the energy requirements significantly, realistically the only way to go is to have a completely wireless power transfer station, but wireless power even in space has numerous problems. heat dissipation is the first that comes to mind. the life cycle of the components a second problem... a solar system with a dyson or partial dyson are realistically the only places where life is going to go extra solar.

      escaping a dying star system is even more problematic, unless you leave millions of years before the power systems fail. but if you're tethered to a solar system for power, then you can't go near light speeds, since you'd out race your power source... so that means non robotic life needs to be synthesized as the destination is approached...

      ah well. we haven't even produced a ship that theoretically could reach the next star system with working electronics, we're a long way away from real extra solar missions.

      worse still, we haven't even gotten to the point where we can deploy a truly sustainable modern world where humans don't wind up filling the oceans with toxic household cleaners... much less all the other problems, like unstoppable population growth, corruption and exploitation of our own kind...

      --
      https://www.gnu.org/philosophy/free-sw.html
    26. Re:Missing something by dpilot · · Score: 1

      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 we could do it. Think about things like no soldering, perhaps laser spot-welds, or perhaps different solders with no lead or tin, laser-heated. Heck, by the time we're thinking starship electronics, maybe we'll want to put the lead back in and get all of the tin out. I'm sure the materials problems have solutions shy of continual nano-repair, but we've never even considered the problem.

      Sometimes I like to muse about the concept of starship electronics - stuff meant for thousands of years. I hadn't actually thought about the packaging - I was thinking more of circuit tricks, gate thickness, electromigration, and other more process, geometry and circuit related things. But you bring up a good point about the packaging. Plus I think a good stiff magnetic field will be in order, a miniature version of the Earth's magnetic field, etc.

      --
      The living have better things to do than to continue hating the dead.
    27. Re:Missing something by Bloke+down+the+pub · · Score: 1

      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.

      They wouldn't bother - they'd just make it up like they do with the rest of science. And history.

      --
      It's true I tell you, feller at work's next door neighbour read it in the paper.
    28. Re:Missing something by hr+raattgift · · Score: 1

      Argh, typo. That should be "metric expansion of space", not "space time" or even "spacetime".

    29. Re:Missing something by Eudial · · Score: 1

      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 expedition.

      --
      GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
  2. Beautiful by PakProtector · · Score: 4, Interesting

    I wish Sagan could be here to see this.

    --

    Edward@Tomato - /home/Edward/ man woman
    man: no entry for woman in the manual.
    "Qua!?"

    1. Re:Beautiful by PakProtector · · Score: 4, 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.

      --

      Edward@Tomato - /home/Edward/ man woman
      man: no entry for woman in the manual.
      "Qua!?"

    2. Re:Beautiful by TheLazySci-FiAuthor · · Score: 1

      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.

      --
      Read my Very Short "Stories"
    3. Re:Beautiful by Reality+Master+101 · · Score: 3, 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.

      --
      Sometimes it's best to just let stupid people be stupid.
    4. Re:Beautiful by morgan_greywolf · · Score: 1

      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.

      --
      My blog
    5. Re:Beautiful by Reality+Master+101 · · Score: 1

      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 that problem gets improved, then other opportunities start to open up. Not to mention, investors are more willing to take risks on your new "useful" usages when there are regular, profitable space trips going on.

      --
      Sometimes it's best to just let stupid people be stupid.
    6. Re:Beautiful by kortex · · Score: 1

      That was my feeling too - I got a geeky little tear in my eye...

      --
      -- kortex "Not everything that counts can be counted, and not everything that can be counted counts"
    7. Re:Beautiful by fishbowl · · 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?

      --
      -fb Everything not expressly forbidden is now mandatory.
    8. Re:Beautiful by CodeBuster · · Score: 1

      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.

    9. Re:Beautiful by The+End+Of+Days · · 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.

    10. Re:Beautiful by fishbowl · · Score: 1

      >Are you sure that they are not coming from outside the United States (Europe, Russia, India, China etc)?

      I am saying that high school graduates from Washington, Oregon, California, Nevada, Utah, Arizona, Colorado, and New Mexico,
      compete effectively with students from the rest of the world. I'm not saying that everybody who goes to school in one of those
      states manages to come out well-educated, but I am noting that the schools are not necessarily depriving them of the opportunity.
      Especially in the sciences, they come out knowing a lot more than I did, essentially skipping a year of math and science that I had to take in college. (I wasn't exactly an underachiever, btw.)

      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. They aren't marginal -- they are highly competitive. The opportunities are there for those students who make appropriate choices.

      --
      -fb Everything not expressly forbidden is now mandatory.
    11. Re:Beautiful by CodeBuster · · Score: 1

      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 universities every year does not necessarily imply that our high schools are delivering a quality educational experience. In fact, IMHO it is more likely that self motivated and intelligent students are seeking their own success (perhaps attending private school if their parents have a few bucks) because they realized that their high school courses were inadequate and took it upon themselves to enrich their own eduction and enhance their individual knowledge and understanding of selected topics outside of the "standard" curriculum (which even they could see was not preparing them adequately for university level study).

    12. Re:Beautiful by ColdWetDog · · Score: 1

      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.

      Well, you can be certain that you're thesis is correct. There are always students who succeed "despite" their formal schooling and I imagine that there is a significant number of persons on this board who fit that description.

      To use a political analogy: A certain number of voters will vote for one person / party / platform pretty much irrespective of what they say or do. A certain number of potential voters won't vote at all. A certain smaller number of voters might be swayed by what the candidate says or does.

      Likewise, some students will do fairly well irrespective of how screwed up the school is, some will fail no matter how good the school is. In this case, I think, there is a larger middle ground where good teachers and supportive environments and quality teaching programs really can affect the student's ultimate performance.

      The "big numbers" don't support any major change in the larger picture although I am not all certain how accurate they are. But somebodies are doing OK.

      Wow, not sure that this rant makes any sense but what the hell.

      --
      Faster! Faster! Faster would be better!
    13. Re:Beautiful by Illbay · · Score: 1

      In fact, it's so bad that he'd probably die BILLIONS AND BILLIONS of deaths.

      --
      Any technology distinguishable from magic is insufficiently advanced.
    14. Re:Beautiful by Illbay · · Score: 1

      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...!"

      --
      Any technology distinguishable from magic is insufficiently advanced.
    15. Re:Beautiful by Domint · · Score: 1

      One would think if he were here, he'd be muttering something about brains, and his desire to eat them.

    16. Re:Beautiful by fishbowl · · Score: 1

      >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?

      They aren't learning Calculus, Physics, Organic Chemistry, French, German and Japanese, on their own.
      People have an idea that public schools are failing because they see headlines about standardized tests, kids graduating unable to read and write, etc. I'm looking at the other end and seeing that there *are* opportunities.

      If I was referring to private school graduates I would have said so. US colleges are not facing some kind of dearth of qualified applicants from US public schools.

      --
      -fb Everything not expressly forbidden is now mandatory.
    17. Re:Beautiful by fishbowl · · Score: 1

      >Well, you can be certain that you're thesis is correct.

      I'm probably too harsh, but I do not read past this. It's a strict policy of mine.
      If English is not your native language, let me know when you try again.

      --
      -fb Everything not expressly forbidden is now mandatory.
    18. Re:Beautiful by PakProtector · · Score: 1

      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.

      --

      Edward@Tomato - /home/Edward/ man woman
      man: no entry for woman in the manual.
      "Qua!?"

  3. Wow by FlyingSquidStudios · · Score: 5, Insightful

    I was going to post the usual attempt at witty snarkiness, but then I actually watched the video... seeing the Moon actually moving around the Earth like that, it actually made my heart skip a beat. Seeing us that way with my own eyes someday, as unlikely as it may be, is something I really long for.

    --
    http://twitter.com/OLDTELEGRAM
    1. Re:Wow by greenguy · · Score: 1

      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.")

      --
      What if I do the same thing, and I do get different results?
    2. Re:Wow by regularstranger · · Score: 2, Informative

      The entire length of the video represents a day on Earth, and since the Earth is about quarter wrt the spacecraft, the video would have to represent about six more days before it would even be possible of the lunar shadow to appear on the Earth (btw, that's a solar eclipse, not lunar). They also have to be perfectly aligned, which would be difficult to judge from a cursory glance at the video. There was no eclipse during May when this video was taken, but there is going to be one on August 1.

      Total Solar Eclipse

  4. Cool, but then again.... by Anonymous Coward · · Score: 5, Funny

    That's cool but then again, I'm a sucker for any movie I'm actually in.

  5. Hey.. by elemnt14 · · Score: 5, Funny

    ..I can see my house from there!

  6. Habitable planets must have large moons? by xxxJonBoyxxx · · Score: 3, Interesting

    "Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe by giving insights into how a distant, Earth-like alien world would appear to us," said University of Maryland astronomer Michael Aâ(TM)Hearn

    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.)

    1. Re:Habitable planets must have large moons? by Sockatume · · Score: 1

      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.

      --
      No kidding!!! What do you say at this point?
    2. Re:Habitable planets must have large moons? by 600Burger · · Score: 1

      http://www.iki.rssi.ru/mirrors/stern/stargaze/Sprecess.htm Having the moon orbit the earth actually slows the earths gyroscopic precession, which slows the ice ages. Though, I don't think that would be a requirement of a habitable planet. The link explains it well.

    3. Re:Habitable planets must have large moons? by Pr0xY · · Score: 1

      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, but would have taken much different evolutionary routes. Most likely with aquatic life forms being dominant.

    4. Re:Habitable planets must have large moons? by pauljlucas · · Score: 1

      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 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 consequence) and their tilts are fairly constant.

      So yes, post-collision and tilt, the moon does keep the tile from varying wildly; but if there were no moon, there wouldn't be a tilt either, and therefore wouldn't be a need to keep it from precessing.

      --
      If you reply, do so only to what I explicitly wrote. If I didn't write it, don't assume or infer it.
    5. Re:Habitable planets must have large moons? by dpilot · · Score: 1

      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-life soup in the oceans, allowing long enough for interesting things to happen. By this theory, life would have gotten its start in the tide pools, and then moved into the oceans.

      3: Crust composition - this one is credited to Dr. A. in "Robots and Earth". (IIRC) As well as creating tides in water, the moon exerts tidal forces on the Earth's crust, itself. Supposedly this kept the crust plastic longer than it might have otherwise, and encouraged outward migration of elements/compounds that might have otherwise been more deeply buried. For Dr. A., this was most notably radioactives, giving the Earth a background radioactivity sufficient to help drive mutations and therefore evolution.

      --
      The living have better things to do than to continue hating the dead.
    6. Re:Habitable planets must have large moons? by adastragrl · · Score: 1

      "Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe by giving insights into how a distant, Earth-like alien world would appear to us," said University of Maryland astronomer Michael Aâ(TM)Hearn

      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.)

      ?? Where in A'Hearn's quote did he say that habitable planets must have moons? In fact, if you read the press release and movie captions, you'll see that it is not expected, although, understanding the lightcurve if a moon is involved would be useful in determining other characteristics of the planet.

    7. Re:Habitable planets must have large moons? by fredrik70 · · Score: 1

      maybe not absolutely needed but it has certanily helped us here

      --
      if (!signature) { throw std::runtime_error("No sig!"); }
    8. Re:Habitable planets must have large moons? by mcvos · · Score: 1

      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.

  7. Mostly... by Anonymous Coward · · Score: 4, Funny

    ...harmless

  8. Missing something, no sound or music ! by MRe_nl · · Score: 1

    Here you go, grumpy old man ; )
    http://www.youtube.com/v/AFks9A9TCF0&hl=en&fs=1

    --
    "Kill 'em all and let Root sort 'em out"
  9. That's no moon... by oodaloop · · Score: 5, Funny

    Whoops, reached my limit for "That's no moon" comments in a single day. No no, don't get up. I'll show myself out.

    --
    Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
  10. Insignficance by magister159 · · Score: 1

    A video like that really helps you realize how small and insignificant you really are.

    The world keeps spinning, doing what it's doing, no matter what you do. We're all just bacteria on the proverbial fruit.

    1. Re:Insignficance by Reality+Master+101 · · Score: 1, Insightful

      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.]

      --
      Sometimes it's best to just let stupid people be stupid.
    2. Re:Insignficance by harry666t · · Score: 1, Interesting

      My point of view is the exact opposite of yours. I'm not something insignificant. Without me, my world wouldn't be the same - it wouldn't even exist. For me, there's no other world but my world, to you, there are no worlds but the one you're living in, etc.

      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.

    3. Re:Insignficance by ortholattice · · Score: 1

      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.]

      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 about this. From what I can tell, the appearance of the first such lifeform seems even more improbable than the development of intelligent life from it - for the latter, we can at least see multiple stages of development in the huge diversity of lifeforms on earth (all with more than 500K base pairs) and come up with an evolutionary theory. For the former, there is a big gap, a big blank, between a soup of random organic molecules and 500K base pairs arranged in just the right order.

      Perhaps the exponent in your "2.55e35 cycles of the universe(s)" is too low by several orders of magnitude? :)

      Incidentally, there is a project by the Venter Institute to develop a "Mycoplasma laboratorium" organism from the 500K base-pair one, stripping out pieces one at a time to find a minimal set of genes that can sustain life. The result of that should be interesting. (They are patenting the thing, which is being challenged, but regardless of outcome hopefully they won't withhold the knowledge.)

    4. Re:Insignficance by Thomasje · · Score: 1
      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. I can think of two good reasons not to do that: first, if interstellar travel is impractical, then those other civilizations will never be more than pen pals, and with interstellar e-mail round-trip times likely to be many years or even centuries, why bother?

      And second, if interstellar travel is practical, do you really want to broadcast the fact that your planet is habitable to all those nice Kzinti out there? We have enough problems without having to deal with alien invasions, thank you very much.

    5. Re:Insignficance by Reality+Master+101 · · Score: 1

      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 of time.

      If life is very common, it seems highly improbable that not one civilization over the last four BILLION years ever decided to expand, either via themselves or by sending probes.

      And second, if interstellar travel is practical, do you really want to broadcast the fact that your planet is habitable to all those nice Kzinti out there?

      Again, it only takes one. Would those Kzinti be shy about seeding the galaxy with themselves? Or, for that matter, will we be shy about it in a few thousand or 10s of thousands of years, when our technology has advanced enough to do self-replicating probes or sleep ships?

      --
      Sometimes it's best to just let stupid people be stupid.
    6. Re:Insignficance by H0ek · · Score: 1

      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 improving our observations of other planets. Now we have better understanding of what to look for in a planet that can sustain life. Sure, astronomers are always looking at extra-solar objects through all the spectrum, but now we have seen the dramatic difference of viewing an inhabitable planet through a spectrum outside (albeit just barely) the visible.

      How will this help? Perhaps it may not, but then again, it's another tool in the detection arsenal. Time will tell.

      Plus, it gives the rabble like myself something pretty to look at.

      --
      H0ek
      Think you're smart? Prove you've got brains!
    7. Re:Insignficance by Thomasje · · Score: 1
      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 of time.

      I think that the problem with that reasoning is that it doesn't take the difficulty of distance into account. Between the stars, you basically have nothing but hard vacuum and absolute-zero cold. Maintaining life support in those conditions means you have to take everything with you, and that is going to limit the distance you can travel if you expect to arrive at your destination alive... 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.

      In other words, I agree that there could be many, many civilizations out there, but the odds of any of them being within reach still seem incredibly slim to me.

    8. Re:Insignficance by adastragrl · · Score: 1

      Is it just me, but when looking the infrared video, it seems like europe is radiating heat like nothing else.

      Europe is covered with lots of plants, which reflect near infrared really well and therefore appear bright in that version. Note how much easier it is to also see South and North America in the near-ir version as opposed to the RGB version.

    9. Re:Insignficance by Reality+Master+101 · · Score: 1

      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 there were someone else. As I said, it only takes one. If you had automated self-replicating probes, it would take even less time.

      Note this only applies to within galaxies. The distance to another galaxy is too absurd at travel at sublight speeds.

      --
      Sometimes it's best to just let stupid people be stupid.
  11. Because real reality isn't real enough... by 14erCleaner · · Score: 4, Funny
    From TFA:

    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...

    --
    Have you read my blog lately?
  12. FMV version? by corbettw · · Score: 1

    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.)

    --
    God invented whiskey so the Irish would not rule the world.
  13. Re:'Shopp'd by mkramer · · Score: 3, Informative

    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 effects that are observable from a nearly singular point of light: regular variances in intensity, spectrum, polarization, etc..

    Likewise, if someday we could do a similar study from one of our probes that's managed to get out of the solar system, that would improve the model another order of magnitude, accounting for other variables in the observation.

  14. Watch Sunshine! by LanMan04 · · Score: 1

    Go watch Sunshine, 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.

    --
    With the first link, the chain is forged.
    1. Re:Watch Sunshine! by FlyingSquidStudios · · Score: 2, Interesting

      I saw Sunshine and I know what you mean, but this is different. This is REAL. That is what the Earth and the Moon actually look like, it's not a CG simulation.

      --
      http://twitter.com/OLDTELEGRAM
    2. Re:Watch Sunshine! by 0xdeadbeef · · Score: 1

      What really kicks up the awe is just how loud sunlight is when you get close...

      That was the stupidest movie since Red Planet.

    3. Re:Watch Sunshine! by Rude+Turnip · · Score: 3, Informative

      Sound is a pressure wave...so yeah, it is loud near the Sun. This was discussed on The Universe (History Channel).

      --
      Bill Clinton: Pimp we can believe in. - The Shirt!!!
    4. Re:Watch Sunshine! by LanMan04 · · Score: 2, Interesting

      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
      http://en.wikipedia.org/wiki/Brian_Cox_(physicist)

      "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 with particularly - there's a particular type of person I enjoy working with in science - all those went to see Sunshine and loved it. They thought that the portrayal of the physicist was wonderful and the emotional impact that science can have on you - the real reason you want to be a scientist - they found that really vivid in the film and enjoyed it a lot.

      But then I see scientists that I think are dull - w*nkers you could call them [laughs] - who have seen it and didn't like it. I can almost use it as a way of working out who I want to work with. I'd say: "Watch this, and tell me what you think of it". If they don't like it, then I don't want to work with them [laughs].

      It's very interesting. These guys that get really pedantic are really, I think, missing the point about what science is all about. It's about precision, when you're doing it. So when you're doing research it's all about precision and attention to detail and that's the difficult bit, and that's what you learn how to do. But deciding what research field you want to do, and having really good ideas about what to go and measure, and what to try and find out, that's a creative process. I think a lot of the pedants kinda miss that.
      Like you say, Sunshine is not a documentary. It's trying to just, in an hour and forty minutes, get across a feeling of what it's like - not only to be a scientist, because obviously there's much more in it than that. So, I found it interesting to watch the kind of people that get upset because the gravity is wrong."

      --
      With the first link, the chain is forged.
    5. Re:Watch Sunshine! by 0xdeadbeef · · Score: 2, Insightful

      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, the suspense is driven by the stupidity of the characters.

  15. Re:*.MOV - WTF? by rfunk · · 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.

  16. Above average? At that distance? by grikdog · · Score: 1

    Just out of curiosity, what bit of rigor ensures that those "extrasolar planets" we're detecting so many lightyears from home are actually resolved images, and not averages of four or five similar, but smaller, objects? It's really unclear to me that the Galilean moons of Jupiter could ever be resolved as four objects and not one "giant moon" from as far away as a half a lightyear.

    --
    ``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
    1. Re:Above average? At that distance? by 0111+1110 · · Score: 1

      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 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. Although that is a Jupiter sized planet. I'm not sure what kind of tech would be required to image something the size of Gliese 581 d, but we don't have it yet. I guess if we had such good imaging capabilities our need to invent interstellar space drives to power interstellar missions would be less compelling. Of course if we had a way to extinguish the nearby star it would make imaging the nearby planets a lot easier.

      --
      Quite an experience to live in fear, isn't it? That's what it is to be a slave.
  17. Earth/Moon Model Screensaver? by Doc+Ruby · · Score: 1

    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".

    --

    --
    make install -not war

  18. Relative albedo of earth and moon by GPS+Pilot · · Score: 2, 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.

    --
    That that is is that that that that is not is not.
    1. Re:Relative albedo of earth and moon by exploder · · Score: 1

      Yes, I first realized this when I saw a sample of moon rock at the Smithsonian. It's almost black.

      --
      Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
  19. Re:*.MOV - WTF? by gatkinso · · Score: 1

    MPEG non-proprietary?

    MPEG2 maybe, but only because the patents have died.

    Think before you post.

    --
    I am very small, utmostly microscopic.
  20. Re:Viewable videos by gatkinso · · Score: 3, Informative

    VLC will play them.

    --
    I am very small, utmostly microscopic.
  21. Re:Viewable videos by Hordeking · · Score: 1

    I'll have to try that. Still doesn't excuse NASA for using proprietary formats. What if in 20 years these codecs aren't available anymore due to architecture/etc? I think that's why there was a big push for Open XML based document formats in the recent past...

    --
    Disclaimer: The opinions and actions of the US Gov't are in no way representative of those held by this author or its ci
  22. Nice Vid by metalpres · · Score: 1

    That video is pretty cool, but didnt anyone else get a really creedy feeling as the moon passed by? Weird...

  23. Re:Viewable videos by jameskojiro · · Score: 1

    Why the hell can't NASA post it in .VIV format????

    --
    Tsukasa: All I really want, is to be left alone...
  24. The buble must burst. by The+End+Of+Days · · 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.

    1. Re:The buble must burst. by harry666t · · Score: 1

      Tell me something. Are you going to think of yourself as something insignificant for the rest of your life just because you turn out to be a part of some larger system that you do not have a great impact on? You are the one who has the greatest possible impact on the most significant thing in your life - your life itself.

      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 ago? Even closer to nothing than I do, because we turn out to live on the same planet, and maybe you can even meet me on the street one day. Hey - I already have an impact on you - you're reading my posts and replying to them!

      Please don't talk about the "outside this planet" point-of-view - ***there's nobody out there(*)*** to have any point of view, and even if there was, you are as significant to them as some other alien could be to you if you were observing their solar system.

      (* or we do not know about them)

      So, it turns out, significance depends *only* on the point of view, and if your point of view is that $RANDOM_SUPERNOVA_OR_SOME_OTHER_ASTRONOMICAL_EVENT demands more of your attention than taking care of your needs, here on Earth, so be it.

  25. Obligatory Alien Quote ! by OricAtmos48K · · Score: 1

    Marked for demolishment for intergalactic highway !

  26. My favorite space pic - Sunset on Mars by ishmalius · · Score: 1

    This is definitely my favorite JPL photo: http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20050610a.html

  27. Extrasolar planet visibility by AlpineR · · Score: 1

    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.

    1. Re:Extrasolar planet visibility by mcvos · · Score: 1

      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?

  28. Umm ... by cgoodric · · Score: 1

    Umm, is it just me or does the orbit of the Moon (the path it takes across the screen) not really match the rotation of the Earth? There seems to be a good 30 degrees of offset between the axis of rotation of the Earth and the axis of the orbit of the Moon. Shouldn't those two be fairly close? (Flame shields up!)

    1. Re:Umm ... by Cat+Panic · · Score: 3, Informative

      It seems that the moon doesn't orbit the earth around the equatorial plane but rather the ecliptic. There's a description here and a nice diagram showing the planes here

    2. Re:Umm ... by cgoodric · · Score: 1

      Ah, thanks. I had thought with the current theory of the Moon having been spun off the Earth after a major collision, it would have an Earth equatorial orbit rather than a solar ecliptic one. Interesting.

    3. Re:Umm ... by ScienceTim · · Score: 3, Informative

      The Earth's axis is tilted 23 degrees from the plane of its orbit. The Moon's orbit is much closer to the same plane as the Earth-Moon orbit of the Sun.

    4. Re:Umm ... by treeves · · Score: 1

      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

      --
      ...the future crusty old bastards are already drinking the Kool-Aid.
    5. Re:Umm ... by Skapare · · Score: 1

      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.

      --
      now we need to go OSS in diesel cars
  29. Re:*.MOV - WTF? by Anonymous Coward · · Score: 1, Funny

    Could you please upload it to youtube? I don't have mplayer installed on my machine.

  30. No by MrMista_B · · Score: 1

    This is what he actually said: ""Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe by giving insights into how a distant, Earth-like alien world would appear to us," said University of Maryland astronomer Michael Aâ(TM)Hearn"

    What he is indicating by that, is not that habitable planets *must* have large moons, but simply that, knowing what a habitable planet that *does* have a large moon (ours) looks like from a distance, will help us disern similar such planetary arrangements.

    Nowhere in that is he trying to make a "habitable planet MUST HAVE large moon ELSE no life" statement.

    Or are you reading something different than I am?

  31. 'Shopped. by mujadaddy · · Score: 1

    Looks fake.

    "Are you being sarcastic?" "I can't even tell anymore."

    --
    Populus vult decipi, ergo decipiatur...
    "Force shits upon Reason's back." - Poor Richard's Almanac
    1. Re:'Shopped. by Spatial · · Score: 1

      "Are you being sarcastic?" "I can't even tell anymore."

      I can tell from some of the letters and having seen quite a few sarcs in my time.

  32. Alien POV by PPH · · Score: 1

    Oceans? We though you had covered 70% of your planet with blue tarps.

    Definitely a low class neighborhood. Move along now.

    --
    Have gnu, will travel.
  33. A word from the EPOXI team by ScienceTim · · Score: 5, Informative

    Hi, ScienceTim here, from the EPOXI team. Let me correct some misconceptions. The purpose of this experiment is to make a measurement of the Earth's spectrum at low spectroscopic resolution that allows us to simulate what an observer would detect from outside the solar system. Although we have spatial resolution in this movie, our scientific results will be obtained by adding up all the light in each of our filters in order to explore the ability to deduce properties of the Earth in unresolved data (we actually have 7 filters, not just the 4 that we show, plus a near-IR spectrometer). This information can be used to evaluate the engineering requirements for future space missions that will have the actual purpose of detecting and characterizing extrasolar terrestrial planets. Such a mission will be able to collect very few photons, so it will be required to do its job with very limited information. Why not just simulate the Earth computationally, since we know a great deal about it? We do this, of course. Converting our detailed knowledge into an accurate simulation is not straightforward, however. Radiative-transfer techniques employ a variety of approximations, depending on the situation, and those approximations may require us to know something that would not be available for an actual extrasolar planet -- as an easy example, the pressure scale height is important for some methods. The EPOXI observation, and others like it that we acquired on earlier and later dates, provide an empirical test for those models. Once we have an empirically-tested model verified, we can apply the techniques from that model to the problem of modeling the apparent spectrum of nearly-Earthlike and not-at-all Earthlike terrestrial planets. Keep in mind that this measurement is an interesting and useful exercise in the value of empirical test, but it is not the primary mission element. Currently, the primary mission element is observations of stars with known planets, to investigate these systems more deeply. We will finish in another month or so. Then we cruise for about a year, then we have a close flyby of another comet, after which the mission will be over. We have lots of good stuff coming.

  34. Something doesn't look right in that video... by d474 · · Score: 1

    Why does the moon not have a bright side like the Earth did, in that video? It almost appears as if the moon is in the shadow of something. Could it be that the moon doesn't reflect IR the same way the Earth does?

    --
    Authority questions you. Return the favor.
  35. why make such incredible assumption by Brigadier · · Score: 1

    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 gravity.

    the whole time they are just being hurled through open space. Lets then say they launch millions of ships instead of just one using probability to navigate space.

    Thus your alien who will use limitted sensory levels (visual ?) to identify a water base dplanet ?

  36. Makes you feel small doesn't it... by advocate_one · · Score: 1
    and we know what we're looking at... and what the smudges on the pretty blue & white globe represent...

    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...

    --
    Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
  37. There's a typo in the headline by martin-boundary · · Score: 1

    Earth and Moon From a Predator's Perspective

    There, that's better :)

  38. Re:Viewable videos by adastragrl · · Score: 2, Informative

    http://epoxi.umd.edu/4gallery/Earth-Moon_vid.shtml You can view the animated gifs in your browser.

  39. Cosmic Tilt-A-Whirl by slyborg · · Score: 1

    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 material will perfectly average out to match exactly that of the Sun.

    Secondly, gravitational interactions between bodies in the solar system, over billions of years, will cause axial wobble. The planets themselves are in elliptical orbits about the Sun that are not coplanar. So their gravitational effects will be oriented at some angle to their rotational axes even if they had zero tilt relative to the ecliptic. Any mass variation in these bodies therefore will experience differential pull. For any non-rigid body, which applies to all of the large bodies in the solar system at some point in their history, there is uneven distribution of mass inside them which changes over time.

    What the Moon did for us, at the "cost" of tidal braking is produce a local gravity well whose effects are much larger than the other influences on our axial tilt, so that these effects primarily result in precession of the tilt axis rather than changes to its overall value. However, this is largely a chance development based on the particular mass ratio between the bodies and the configuration of our solar system. If the Earth-Moon system orbited closer to a jovian with a large inclination, the overall effect could have been to de-stabilize the rotational axis.

    Wiki has useful page on this topic:

    http://en.wikipedia.org/wiki/Axial_tilt

  40. Fsck all of you. by mosel-saar-ruwer · · Score: 1


    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.

  41. Re:Viewable videos by mcvos · · Score: 1

    VLC will play them.

    How is this informative? VLC will play anything. Everybody knows that. Right?

  42. Re:Viewable videos by mcvos · · Score: 1

    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.