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What would rings around Earth look like?

The views expressed are those of the author and are not necessarily those of Scientific American.


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A video currently making the rounds on the Web ponders an intriguing astronomical scenario: What if Earth had rings, as Saturn does?

If the animation below, by YouTube user Roy Prol, is to be believed (and it seems to jibe with related imaginings, such as one in a NASA educator guide about Saturn [pdf]), rings would be a stunning addition to Earth’s sky, day or night. And Prol’s video shows that rings would make a heck of a nice backdrop for photographers of terrestrial landmarks (for example, Paris’s Eiffel Tower, Rio’s Christ the Redeemer, Australia’s Ayers Rock) around the globe.

But such a ring, if it were to suddenly appear, might not be all good news. Decades ago, John O’Keefe of the NASA Goddard Space Flight Center ventured that Earth may have had a ring system similar to Saturn’s for a brief period. In a 1980 paper in Nature, O’Keefe pointed to climatic data indicating colder winters at the end of the Eocene epoch some 34 million years ago along with showers of tektites, glassy rocks of mysterious origin, at around the same time. O’Keefe’s theory held that tektites that missed the Earth in this bombardment were captured into a ring system that may have persisted for millions of years, casting a winter shadow across Earth’s surface and contributing to a late Eocene die-off of many marine organisms such as plankton and mollusks.

If Earth may have once had rings, why doesn’t it now? Two reasons come to mind, says planetary ring scientist Linda Spilker of the NASA Jet Propulsion Laboratory in Pasadena, Calif. The first is the massive moon that drives our tides and helps stabilize Earth’s tilttwo effects that make our planet so habitable. "The tidal pull from our moon would be very good at disrupting and dissipating any sort of ring," Spilker says. "Second, the solar perturbations (tidal pull from the sun) are much larger at Earth, and the terrestrial planets, than they are at Jupiter and outward." Those forces would break up a ring, Spilker adds, and the push from solar photons and streaming charged particles in the solar wind would disturb small constituents in Earth-centric rings as well.





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  1. 1. qraal 3:37 pm 11/25/2009

    Way cool! I want rings now!

    Link to this
  2. 2. rockjohny 4:17 pm 11/25/2009

    Would be like living in a Halo game.

    Link to this
  3. 3. Jockaira 10:27 am 11/26/2009

    Not silly, just beautiful. Blue skies are nice but usually very boring. A sky with a wide arc across it would be an inspiration to poets, and in ancient times, a sure incentive to scientists to look up and ponder the reasons for its existence. It surely would have accelerated understanding of the universe by its very mysterious and dominating character. And imagine the myths it would have written in the pre-scientific world.

    Link to this
  4. 4. Algie 11:51 am 11/26/2009

    I wonder if an artifical ring system, placed in orbit by NASA could help eliminate space junk by creating a gentle drag on objects passing through it, accelerating drag and re-entry into the Earth’s atmosphere?

    Link to this
  5. 5. brsecu 2:37 pm 11/27/2009

    Artificial ring system to terraform Venus?

    Link to this
  6. 6. mceltix2000 12:37 am 11/28/2009

    4 words: blow up the moon! —> NOW! darnit, I want rings! ;)

    Link to this
  7. 7. gassners 9:23 pm 11/28/2009

    I would have presumed such rings to have a grainier appearance from the surface of the earth. The striped appearance shows graininess of dust particles. But what if the dust presumed, were really comprised of many independent satellite objects? Another aspect missed by the simulator, is the effect of "twinkling." Stars twinkle due to random variations in air pressure. Just as the author observes that the width of the rings would appear greater from northerly and southerly positions, so, the amount of twinkling would vary more greatly across the latitudes and longetudes of the rings. Similarly, it is unlikely that the observer’s view would ordinarily include images from horizon to horizon, as ordinary weather patterns are seldom as clear as those provided in the simulation.

    But still – this simulation gives a striking perspective.

    Would not the Moon create perturbations in the ring density caused by gravity waves?

    Link to this
  8. 8. Umcarr53 1:19 am 11/29/2009

    We could do this if we really wanted it. Take a few asteroids, manouvre them into earth orbit, blow them up or have them disassembled robotically or by workers. The rings probably wouldn’t last in terms of geological time scales, because of the moon and sun, but they wouldn’t dissipate immediately right?

    If it came to raising money for such a project, I couldn’t help noticing that a landmark on the rings would let people know how quickly they orbited our planet. In fact, why not have a bunch of them? And if you have robots up there already from the disassembly, they could conceivably control the movements of each chunk of rock. Using that, you could have intelligent arrangements and patterns that can change. But since making and maintaining the rings would be prohibitively expensive, you could sell them as advertising space. With decent weather, you could literally advertise across the planet with the mother of all jumbo-trons. You could turn some of the rocks into enclosed biomes, and sell them to the rich for an easy escape from the overcrowding of our planet. Or turn them into farms and (safely) ship the poor into orbit to work and to feed more people.

    As much as I think that would ruin the beauty of the rings, I wouldn’t mind living in a society capable of literally writing it’s own name in the sky.

    And yes, I do read too much Sci-Fi.

    Link to this
  9. 9. evolvedstardust 9:15 pm 11/29/2009

    The video certainly is inspiring, if not unrealistic. As the article points out the gravity influences of the Sun and Moon would quickly destroy a Saturn type ring. It doesn’t seem likely that all of the ring material would miss falling to Earth.

    If we gained the rings at the expense of the Moon what would there be to stabilize the Earth’s rotation?

    Considering the light scattering effect of the Full Moon on the night sky, it would seem we would suffer perpetual twilight for the duration of the ring’s existence. We could say goodby to astronomy from the Earth’s surface.

    Since ring systems (and the Moon for that matter) would orbit at or near the Earth’s equator spacecraft leaving or approaching the Earth would have some serious navigation problems.

    And it probably would not take long for marketing interests in high northern and southern latitudes to subject us to endless scrolling ad messages with laser projections onto the rings.

    No good can come of this fantasy.

    Link to this
  10. 10. Gourdhead 4:11 pm 11/30/2009

    You gotta problem with that?

    Link to this
  11. 11. Michael Hanlon 1:18 am 12/1/2009

    The presence of rings such as these would preclude the use of solar sails anywhere near the Earth for reasons of particle impinging and added shadow.
    There goes our investment in solar photovoltaic power generation.

    Link to this
  12. 12. Michael Hanlon 1:24 am 12/1/2009

    Hey, Mr. Roy Prol, how about showing us how the Moon would look with the rings?

    Link to this
  13. 13. Michael Hanlon 3:59 am 12/1/2009

    Skip that request Mr. Prol. I just ventured outside (3 AM) and there’s nearly a full moon this evening and there were high altitude ice crystals which put a halo around the orb. That’s an unusual event here in south Florida. But, now I know I wouldn’t need to have it that way every night.

    Link to this
  14. 14. Quinn the Eskimo 12:36 am 12/2/2009

    Now that they have been "invented" and photographed–Bill Gates will announce that Microsoft has the patent.

    You’ve been warned.

    Link to this
  15. 15. biosensei 5:29 pm 12/3/2009

    It appears we already have the makings of a ring system in the colossal amount of space junk up there, it just needs organising into an equatorial orbit… a job for young offenders, perhaps, with the dual benefits of keeping them well out of the way until they’ve done the job and giving them a truly global perspective on life; and if they try throwing things at us down here, they push themselves into a more distant orbit!!
    2 months in a spacesuit and nappies/diapers would reform most people, I suspect!

    Link to this

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