Two Rings To Rule Them All: Amazing Space Discovery

We know know what the famous announcement by the European Southern Observatory is. They found an asteroid with ring! Two of them!

...the remote asteroid Chariklo is surrounded by two dense and narrow rings.

Telescopes at seven locations in South America, including the 1.54-metre Danish and TRAPPIST telescopes at ESO’s La Silla Observatory in Chile were used to make this surprise discovery in the outer Solar System.

This unique finding has sparked much interest and debate since it is the smallest object by far to have rings and only the fifth body in the Solar System — after the much larger planets Jupiter, Saturn, Uranus and Neptune — to have this feature.

Astronomers think that this sort of ring is likely to be formed from debris left over after a collision.

Details here.


More like this

"Don't go around saying the world owes you a living. The world owes you nothing. It was here first." -Mark Twain So, you've been around a while, seen all sorts of things, and learned an awful lot about the world, solar system and Universe that we live in. But how well do you know it, really? Image…
"Imperfection clings to a person, and if they wait till they are brushed off entirely, they would spin for ever on their axis, advancing nowhere." -Thomas Carlyle When you take a look up at the sky, the two most prominent objects are the Sun and the Moon. And every day, like clockwork, they rise…
"A journey is a person in itself; no two are alike. And all plans, safeguards, policing, and coercion are fruitless. We find that after years of struggle that we do not take a trip; a trip takes us." -John Steinbeck Here on Earth, we all get to enjoy the delight of being located in an extremely…
"The phenomena of nature, especially those that fall under the inspection of the astronomer, are to be viewed, not only with the usual attention to facts as they occur, but with the eye of reason and experience." -William Herschel We typically think of Saturn as our Solar System’s ringed world,…

Layperson speculation on a mechanism:

Object A gets hit by Object B. Large quantity of debris is ejected and goes into orbit around Object A. The debris cloud elongates as it orbits.

The higher-mass debris ends up falling back to Object A (and depending on Object A being a rocky object, we might observe a band of returned debris around the circumference of Object A). The lower-mass debris ends up escaping Object A's gravity and dispersing into space.

The debris that is of intermediate mass continues to orbit Object A. The interaction of angular momentum and gravity confines the debris to a narrow range of distance from the surface of Object A. And the tendency of everything toward dissipation, causes the debris cloud to diffuse as far as possible while staying within that range of distance.

The result of that interaction and dissipation, is the ring: an evenly-dispersed debris cloud at a particular orbit around Object A.

OK, feel free to tell me where I screwed up with that.

G: I don't know. What I've heard is that the whole thing is a bit controversial, meaning that astronomers may disagree internally about how rings are formed. Perhaps these rings are impossible for some reason, i.e. because of the small size of the asteroid, by one or more major theories of how they form.

So get the popcorn out!

G: Your model would give a single broad ring, rather than two narrow rings as reported. That doesn't mean the rings aren't the result of a collision, but rather that there must be something else going on as well. A shepherd moon, for instance (this is how some of the narrower rings at Saturn and Uranus are maintained).

The dynamical stability of this ring system is also an interesting question. How long does it take for rings like this to form, and how long do they last until something disrupts them? I don't know the answers to those questions (it's not my field), but they are important constraints on any theory of how these rings formed.

By Eric Lund (not verified) on 27 Mar 2014 #permalink

I think this is indeed one of the most surprising and amazing discoveries of 2014.

Would never have guessed and staggered to find an asteroid can somehow maintain a ring system - would've thought it was far too low mass to do so.

Shared, great article and news - cheers and Happy New Year to Greg Laden & y'all.

By Astrostevo (not verified) on 30 Dec 2014 #permalink