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Space NASA

Scientists Discover Outer Space Isn't Pitch Black After All (npr.org) 88

Posted by BeauHD from the unexplained-light dept.
Researchers with NASA's New Horizons say they've finally been able to determine if space is truly black. The group has posted their work online, and it will soon appear ini the Astrophysical Journal. NPR reports: New Horizons was originally designed to explore Pluto, but after whizzing past the dwarf planet in 2015, the intrepid spacecraft just kept going. It's now more than four billion miles from home -- nearly 50 times farther away from the Sun than the Earth is. That's important because it means the spacecraft is far from major sources of light contamination that make it impossible to detect any tiny light signal from the universe itself. Around Earth and the inner solar system, for example, space is filled with dust particles that get lit up by the Sun, creating a diffuse glow over the entire sky. But that dust isn't a problem out where New Horizons is. Plus, out there, the sunlight is much weaker.

To try to detect the faint glow of the universe, researchers went through images taken by the spacecraft's simple telescope and camera and looked for ones that were incredibly boring. Then they processed these images to remove all known sources of visible light. Once they'd subtracted out the light from stars, plus scattered light from the Milky Way and any stray light that might be a result of camera quirks, they were left with light coming in from beyond our own galaxy. They then went a step further still, subtracting out light that they could attribute to all the galaxies thought to be out there. And it turns out, once that was done, there was still plenty of unexplained light.

In fact, the amount of light coming from mysterious sources was about equal to all the light coming in from the known galaxies, says Marc Postman, an astronomer with the Space Telescope Science Institute in Baltimore, Maryland. So maybe there are unrecognized galaxies out there, he says, "or some other source of light that we don't yet know what it is." [...] So where does the light come from? Perhaps, he says, there are far more small, faint dwarf galaxies and other faint regions on the outskirts of galaxies that instruments like the Hubble Space Telescope can't detect and so scientists just aren't aware of them. Or, maybe there's more dust out there interfering with the measurements than scientists expected. Or perhaps there's a more exotic explanation -- some unknown phenomenon out in the universe that creates visible light. It's even possible it's something associated with dark matter, a mysterious form of matter that exerts a gravitational pull on visible matter but has never been seen directly.
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Scientists Discover Outer Space Isn't Pitch Black After All More

Scientists Discover Outer Space Isn't Pitch Black After All

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  • Surely I don't need to say it!
    • dark light is the best of them all.

  • SCTV skit (Score:5, Funny)

    by magusxxx ( 751600 ) <magusxxx_2000 AT yahoo DOT com> on Thursday November 19, 2020 @02:13AM (#60741746)

    "In the beginning there was nothin'...then God said let there be light.
    And there was still nothin'...but you could see it." - Dave Thomas

  • Pixel noise (Score:3)

    by hcs_$reboot ( 1536101 ) on Thursday November 19, 2020 @02:13AM (#60741748)
    counts as well.

  • No shit. (Score:5, Insightful)

    by wierd_w ( 1375923 ) on Thursday November 19, 2020 @02:20AM (#60741762)

    The microwave background ALONE means that space is not perfectly black. It is a very very deep shade of red.

    • The microwave background ALONE means that space is not perfectly black. It is a very very deep shade of red.

      TFA is about visible light.

      The CMB is what you would expect from a blackbody at 4K. But the amount of visible light is way more than a BB would produce.

      • That's true but it still means the title is completely wrong. We have known for decades that space is not pitch black. Now we know it is even less pitch black than we thought.

      • Re: (Score:2)

        by PPH ( 736903 )

        TFA is about visible light.

        Visible to whom?

        Oh Magoo! You've done it again.

  • is 6,437,376,000 kilometres

  • New Horizons' cameras are better than Voyagers', so they can do outer-solar-system experiments the Voyagers couldn't. Too bad they couldn't find another asteroid (Kuiperoid?) to visit after Arrokoth (AKA Ultima Thule). New Horizons still has a decent amount of navigation fuel.

  • "Space is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. You may think it’s a long way down the road to the chemist, but that’s just peanuts to space."

  • How else could he see in the dark before he created all the stars and galaxies in 7 days? I mean come on, use a bit of logic here people!

  • Particles pop into existence, and get destroyed all the time, everywhere in space, it would not be unthinkable some may decay losing a photon, or may excite an electron that may fall back to a lower energy state.

    Another thought could be that gravitational waves are interacting with existing ordinary matter in some way.

  • What? Pitch Black is a lie? I paid money to watch that documentary and its sequels with Vin Diesel. When are they going to send me money back?

  • We knew that since Elite II: Frontier. What else is news?

    PS. For those who don't know, the blue space of that amazing space simulator was supposed to represent the light of distant background stars in the low resolution monitors of the era.

  • And next thing they'll prove is that in space somebody can hear you scream.

  • I don't know who said it, but one proof for the universe not being infinite was that in an infinite universe, one filled with an infinite number of stars, there couldn't be a black background, because the sum of infinite star light would not allow for an absolute blackness.

    So when space isn't pitch black does this raise the old question if space could perhaps be infinite.

    • Re:Is space infinite? (Score:5, Informative)

      by Whibla ( 210729 ) on Thursday November 19, 2020 @06:32AM (#60742112)

      Assuming we're talking, as the article is, about visible light then that 'proof' doesn't satisfy the sniff test.

      How fast is this infinite universe expanding? If point 'a' is receding from point 'b' faster than the speed of light then no light from 'a' will ever reach 'b'.

      Assuming the above is not generally true, did one or more periods of 'expansion' happen? How long will it take the light from point 'a' to reach point 'b', given the distance between them, the rate of expansion of the universe, and the periodicity (if any) of the period(s) of expansion? Has the universe lasted that loing?

      Where within this infinite universe are we measuring from? Infinite doesn't mean no edges, only that in at least one direction it doesn't end (Aleph 0 if you will). If one is located right on the edge well over half the sky might be completely 'lightless'. Of course this does beg the question: what happens to light that hits the 'edge' of the universe?

      How fast does light 'decay' into a non-visible form?

      So, sure, for a particular infinite universe it might be 'bright', but that presupposes a particular set of conditions which make that possible. That sounds somewhat self fulfilling to me. Without those initial constraints however I'd say it was entirely possible to have an infinite universe set against a dark background...

      • Sorry, but you're obfuscating my question. The assumption of there being an infinite number of visible stars flooding the universe with light doesn't allow for an infinite expansion at the speed of light as it obviously would leave you with a finite and diminishing number of visible stars.

        But you do raise an interesting point, because when or if we can proof that there is no absolute blackness in space then how can there be an infinitely accelerating expansion? An expansion can still be infinite, but it wou

        • Re: (Score:2)

          by Whibla ( 210729 )

          Sorry, but you're obfuscating my question. The assumption of there being an infinite number of visible stars flooding the universe with light doesn't allow for an infinite expansion at the speed of light as it obviously would leave you with a finite and diminishing number of visible stars.

          In your original post you posited "an infinite universe, one filled with an infinite number of stars". Nothing was said about them all being visible (in terms of 'from a single point' not as in 'radiates visible light'. The latter was taken as read.). No obfustication on my part! Insisting that there are an infinite number visible from any particular point at any one point of time essentially brings us back to my point about the presuppositions made: after all, given that we can only see a finite amount of

          • The reason why I mention multiple Big Bangs is because this is something that is being discussed at the moment and I didn't mean to just bring new ideas simply for the purpose of these being new. Rather does the multiple Big Bang theory claim to have proof. A discovery of a non-black universe could lead to further proof, which would be exciting news.

            https://www.techtimes.com/arti... [techtimes.com]

            • Re: (Score:3)

              by Whibla ( 210729 )

              Interesting, though the cyclic universe theory has been around for as long as I can remember thinking about these things. Putting it in the realm of 'real science' as opposed to 'science fiction' with the suggestion of proof though, that's new.

              As for Penrose's notion: I can't help but be sceptical. The big bang posits that all matter / energy existed in a 'point' of near infinite density before expanding into the universe we know. 'Outside' this 'point' is 'not universe'. In other words the space time of ou

            • Re: (Score:2)

              by Whibla ( 210729 )

              I don't want to go off on one, but I'm afraid you put a bit of a bee in my bonnet.

              Fortunately this [youtube.com] appeared in youtube's "suggested videos" feed, so I now have a (slightly) clearer picture of CCC, the theory formulated by Penrose, which was the basis of the snippet you linked to.

              After watching it through I had a few thoughts of my own (no doubt purloined from someone else, sometime back, and now buried in my 'subconscious'). The primary one was that he might, somewhat ironically, actually be spot on when he

    • Re: (Score:2)

      by jythie ( 914043 )
      That would only really apply if the universe was also infinitely old.

  • This was already known. (Score:3)

    by thegarbz ( 1787294 ) on Thursday November 19, 2020 @06:25AM (#60742106)

    We already pointed the Hubble at nothing and found that nothing was full of galaxies even with our ancient detection equipment. Then there's the well known theory that in any direction you look you should get hit by a photon. This was partially addressed in a minute-physics video years ago https://www.youtube.com/watch?... [youtube.com]

    • This puzeled Newton.

      He correctly noted that if the universe was infinite and had a roughly even number of stars per unit volume at some huge scale, then by summing the series of rings around the earth he quickly realized that the sky would not be dark, but rather we would roast!

      He inferred that they Universe cannot be infinitely big. And we now know that the light horizon is 13 billion years away.

  • So Olber's paradox is true?

    • So Olber's paradox is true?

      Well, it makes some really bad assumptions, but Olber came to mind as soon as I read the article. The better we can sense photons, the more it shows that it looks like stars all the way down.

      But red shift, light attenuation, and now intergalactic dust, we have a lit universe.

  • Black Ice ain't black either.

  • ... is a nondiscrete bubble inside the primordial superdense mass. It's actually been imploding the entire "time"!

  • Reading the article reminds of that Sherlock Holmes quote: if you have eliminated the impossible, whatever remains, however improbably, is the truth. In this case, why not consider that empty space doesn't really have the light that this camera on New Horizons claims it has - i.e thats what is impossible. If one starts with that axiom, then what follows is that the camera has a source of error that we have not discovered before. Perhaps there is some source of noise that is causing the effect of light being

  • When reached for comment, Space made a statement that it was relieved that it is no longer being threatened with a lawsuit for violating Anish Kapoor's Vantablack copyright. (context: https://www.smithsonianmag.com... [smithsonianmag.com] )

  • I'm slightly skeptical - and hopefully my skepticism can be easily answered. But my skepticism has to do with measurement biases.

    I read what I could of the scientific publication, but I'm not experienced at reading these things - so I'm also skeptical about my skepticism. My thoughts range around the following:

    • [A] Differential aging between the masked (covered) pixels and the exposed pixels over time
    • [B] Whatever cloud of stuff surrounds New Horizons - expelled maneuvering propellant, off-gassing of plas

  • Refraction from cosmic particles. (Score:3)

    by jellomizer ( 103300 ) on Thursday November 19, 2020 @11:35AM (#60743018)

    Outer space isn't 0k so there is energy floating around, so it will hit a particle, which will reflect, refract, or radiate an emission. If you multiply all the near 0 energy by the size of the universe, you will probably get something more noticeable.

  • Photons in motion have mass. Wouldn't it be funny if nobody ever bothered to do the math to verify that the missing mass are all the photons in the universe. They may not have much mass, but there are *a lot* of them.

    The idea that dark matter == light makes me chuckle.

    • Re: (Score:2)

      by PPH ( 736903 )

      Photons in motion have mass.

      Not exactly. They have momentum.

      Newton actually got his definition of the second law of motion right (although I don't think he realized the implications of relativity):

      "The rate of change of momentum is proportional to the imposed force ..."

  • I think they just proved the universe is infinite. (Score:3)

    by nbritton ( 823086 ) on Thursday November 19, 2020 @12:00PM (#60743120)

    They said that about half of all light was unaccounted for. Light follows the inverse square law, so if you represent all light in the observable universe as a geometric series, then the second half of the series can be accounted for as the all the light from the edge of the observable universe to infinity.

    • Re: (Score:1)

      by Anonymous Coward

      You can't see light beyond the observable universe. No matter how faint. Because it's not about intensity, it's about time and distance.

  • I define black as light that fails to exceed the threshold of detection by the human eye.

  • By definition, space is black. Anything that's matter or energy of anything is not space, by definition. So when you pick up something that's "not space" I don't see the point of saying "hey, space isn't black!".

    Now, I get the distinction here they mean "outer space" or "the area of space and matter described by a volume way away from light sources" or however you want to phrase it. But it still annoys me - yes, space _is_ black.

  • ... is the cosmic background radiation?

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