back to article Boffins discover new dust clouds in the Solar System, Mercury has a surprisingly filthy ring

Scientists have spotted, for the first time, gigantic dust rings circling the Sun alongside the orbits of Mercury and Venus. The Solar System is nothing but our star, a few planets, some satellites, lots of little rocks, and a load of dust. As asteroids collide and comets burn up, leftover crumbs are scattered around space, …

  1. Blockchain commentard Silver badge
    Boffin

    Now are they too embarrassed to state that Uranus has a dusty ring?

    1. bombastic bob Silver badge
      Trollface

      when I read the article's title, I thought of an old TV commercial for a product to fight "Ring around the collar". I imagined a group of naughty children chanting "Ring around the planet! Ring around the planet!"

  2. Semtex451 Silver badge

    "People thought that Mercury, is too small and too close to the Sun to capture a dust ring"

    So it hasn't been there since the formation of Mercury? Ah Mercury formed elsewhere and got knocked /pulled in to where it is, and has since captured this dust, right?

    1. Anonymous Coward
      Anonymous Coward

      Commentards downvote questions on this site a lot I've noticed.

      Does this sites readership demographic not welcome questions, or is because they are considered stupid questions? Or is there some other reason?

      I'll design a survey.

      1. Semtex451 Silver badge
        Facepalm

        You realise you've just asked at least two more questions, right?

        1. A.P. Veening

          You also managed to ask one more question, he however avoided a down vote (at the time of writing this at least) ;)

  3. eldakka Silver badge
    Coat

    Venus has a few surprise lumps in her ring

    Should get that checked out by a doctor, sounds like hemorrhoids.

    1. zuckzuckgo

      Can we just stop talking about Uranus.

  4. Doctor Syntax Silver badge

    "Earth’s even got its own debris zone."

    Probably includes all the toys that keep getting thrown out of the pram.

  5. Bangem

    Make Pluto great again

    Taking this on board, isn't part of the "definition of a planet" that it must clear it neighbourhood of smaller objects? By that logic either

    1. Earth, Venus and Mercury should all now be defined as minor planets or

    2. Make Pluto a planet again!

    1. Loyal Commenter Silver badge

      Re: Make Pluto great again

      Look again at the picture in the article. You can clearly see that the immediate neighbourhood around the planets (to several diameters) is cleared. I'm not sure what the exact definition of 'neghbourhood' is in these terms, but I'm pretty sure they all make the grade.

      I appreciate that the picture is illustrative and clearly not to scale, but the reasonable implication here is that the dust rings orbit the sun at the same rate as the planets (any slower, and they would fall towards the sun, and faster, they would move away), so the bits that are not close to the planets never will be.

      1. Mad Mike

        Re: Make Pluto great again

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

        By the above definition, the whole orbit of the planet must be cleared and therefore none of Mercury, Venus or Earth are planets, as their orbits are not cleared. This is the definition used by the IAU. So, the original poster is quite right. By current terminology, none are planets.

        1. Aladdin Sane Silver badge
          FAIL

          Re: Make Pluto great again

          "meaning it has become gravitationally dominant, and there are no other bodies of comparable size other than its natural satellites or those otherwise under its gravitational influence".

        2. Spherical Cow

          Re: Make Pluto great again @ Mad Mike

          "https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

          By the above definition, the whole orbit of the planet must be cleared and therefore none of Mercury, Venus or Earth are planets, as their orbits are not cleared."

          There's more to the definition, size matters: "there are no other bodies of comparable size other than its natural satellites or those otherwise under its gravitational influence." Therefore dust & small rocks don't count and don't have to be cleared. By current terminology, Mercury, Venus and Earth are planets in dusty orbits.

      2. james 68

        Re: Make Pluto great again

        Your forgetting about the mass. Unless each mote of dust has the same mass as the planet it shares an orbit with then it won't be orbiting at the same velocity as that planet.

        1. STOP_FORTH

          Re: Make Pluto great again

          That's not how gravity works. Leastways the Newtonian sort.

        2. algoc

          Re: Make Pluto great again

          You weren't paying attention in school. The mass is irrelevant to the orbital speed.

          GMm/(r^2) = m(v^2)/r

          The 'm's cancel.

          1. james 68

            Re: Make Pluto great again

            I was paying attention in school which is why I know that the mass IS relevant. Speculation on my education aside, you might want to refresh your memory on Kepler's laws of motion, I'll even supply a quick primer http://homepages.wmich.edu/~korista/Newton-Kepler.html

            1. englishr

              Re: Make Pluto great again

              Thank you for the link, but my reading of the page is that it is contrary to your understanding. Could you draw attention to the parts that support your argument that orbital velocity in a solar orbit is a function of the mass of the orbiting body?

              From the web page referenced:

              So does the mass of the planet have a significant impact upon its orbital period (or orbital speed) about some star? Given that planets are by definition almost always much less massive than the stars they orbit, the practical answer is "NO."

      3. teamonster

        Re: Make Pluto great again

        By this (laughable, but officially accepted) definition, Jupiter isn't a planet. Jupiter has two groups of asteroids leading and trailing it's orbit. Jupiter's orbit is not clear, thus, it is not a planet.

        This is why people are getting upset with the IAU. The 'definition' was railroaded through by a small minority of members who seem to have got their diplomas from poundland.

    2. herman Silver badge

      Re: Make Pluto great again

      By that argument, the fact that Pluto exists, means that Neptune is not a planet.

    3. mr.K

      Re: Make Pluto great again

      Like it or not, but this is not what the definition entails. "Clearing the neighbourhood" was never intended to mean and does not mean that the neighbourhood should be completely empty. That will be an impossible standard for a number of reasons, the obvious one are the moons. A little harder to grasp is all the minor objects that will end up in the stable Lagrange points L4 and L5 or orbit both in a horseshoe orbit. And I suspect most of this dust have in fact a horseshoe orbit. Read more about it:

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

      Third we have the orbital resonances of some bodies. Pluto is in such a resonance with Neptune, but so is Orcus which have the exact same orbit as Pluto.

      And this is exactly the point of all these examples. Remove Neptune and Pluto will eventually pull Orcus in and they will merge. As of now their orbit is not their neighbourhood, it is Neptune's. The Trojans are not merging because of Jupiter. The same with the asteroid belt etc. They obviously was aware of this, and no they have not made a definition that excludes Jupiter and Neptune by mistake.

      Personally I think we should remove the criteria and have a larger number of planets and instead call the eight major planets or something. I really fail to see why it was an argument that they had to because if Pluto should be a planet then a lot of other bodies would be planets to. So what? Regardless the definition they have now stands perfectly well. But I bet it will exclude exoplanets at some point that we would really think of as planets.

      1. Mark 85 Silver badge
        Coat

        Re: Make Pluto great again

        Maybe a campaign should be started... something like "Make the Solarsystem Great Again"?

        I'll get my coat. It's the one with the small rocks and a large amount of dust in the pockets.

        1. zuckzuckgo

          Re: Make Pluto great again

          So what colour would the MPGA hat be? Would it include big floppy ears? Would the Minnesota Public Golf Association sue us over trademark rights? All important questions that must be answered before your proposal can be taken seriously.

  6. aregross

    "...if the dust grains are all packed together, it would only create an asteroid about two miles across"

    I just looked under my bed. Using the above analogy, I probably have a quarter mile of dust under there!

    1. Spherical Cow

      1: household dust is dead skin cells. 2: monsters live under the bed. Conclusion: you have a quarter mile of monster skin.

      1. aregross
        Pint

        Well Played! 'av a Pint on me!

  7. Gene Cash Silver badge

    How very Kerbal

    “The dust close to the Sun just shows up in our observations, and generally, we have thrown it away,” — Russell Howard, US Naval Research Laboratory

    "Pol was finally discovered when someone decided to write down the location of the pollen, after having given up on yet another failed attempt to be rid of the smudge." — Kerbal Astronomical Society

    https://wiki.kerbalspaceprogram.com/wiki/Pol

    1. Semtex451 Silver badge

      Re: How very Kerbal

      At some point all fields need to re-examine things with a fresh pair of eyes

  8. livin' thing
    Paris Hilton

    Paris...

    ...because.

  9. Celeste Reinard

    Old Stuff

    So they found some dust. Next thing they'll discover some cobwebs, mothballs and an odd sock. A skeleton... or even a planet that has developped intelligent life, that has invented the steam engine. Maybe someone give the boffins a hint what else to look for? Dirty magazines?

  10. DJV Silver badge

    Dust

    Don't tell my ex-wife's mother otherwise she'll be out there perpetually flicking at it with a duster!

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Biting the hand that feeds IT © 1998–2019