first ringed asteroid found

[dragon]

(CNN) -- Quick -- name a planet with rings. Easy, right?

But Saturn and others are not alone: Now scientists have added another celestial body to the short list of objects in our solar system that have rings around them.

The remote asteroid Chariklo orbits between Saturn and Uranus in the outer solar system. Researchers published a study in the journal Nature showing evidence of rings around it.

Lead author Felipe Braga-Ribas of the Observatorio Nacional/MCTI in Rio de Janeiro said the discovery came as a complete surprise.

"We weren't looking for a ring and didn't think small bodies like Chariklo had them at all," he said in a statement.

Chariklo is fairly small -- 250 kilometers (150 miles) in diameter. It is classified as a "centaur," an object that has an unstable orbit and crosses giant planets' orbits. Mythological centaurs had both human and horse features, while centaurs in the solar system may have both comet and asteroid characteristics.

The asteroid is only the fifth solar system object whose rings have been detected. Jupiter, Saturn, Uranus and Neptune also have rings.

Telescopes at seven different locations, including the European Southern Observatory's La Silla site in Chile, saw a star seem to disappear for a few seconds on June 3, 2013. This happened because the star's light was obscured by Chariklo.
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The star's brightness also diminished a few seconds before and after that main blocking of light. Astronomers discovered that rings were responsible, and calculated their size, shape and orientation.

The two rings orbiting the asteroid are relatively narrow: 7 kilometers and 3 kilometers across. They are separated by a gap of 9 kilometers. Scientists are informally calling these rings Oiapoque and Chui, after rivers near the northern and southern ends of Brazil.

The gravitational interactions from small moons may be keeping the orbiting material in ring form, scientists said.

"So, as well as the rings, it's likely that Chariklo has at least one small moon still waiting to be discovered," Braga-Ribas said in a statement.

READ: Mystery of Mars 'doughnut rock' solved

And someday the rings themselves may lead to a moon being formed, scientists said. On a larger scale, a similar process could have been involved in the making of our own moon, as well as other planetary satellites.

How these rings came to be is mysterious. One idea is that a collision created a disc of debris, the European Southern Observatory said.

"This discovery suggests that the event(s) responsible for the origin of the rings is relatively recent, or that a fortuitous balance of forces have combined to help sustain them," said Ed Beshore, deputy principal investigator for NASA's OSIRIS-REx mission, which aims to visit a near-Earth asteroid and bring a sample back to Earth. Beshore was not involved with this study.

Scientists planning OSIRIS-REx, targeting an asteroid called Bennu, are finding challenges with the dynamics of small celestial bodies, Beshore said. The Nature study reinforces the idea that asteroids, comets and other relatively small bodies are "no longer second-class citizens in our solar system," he said.

"Indeed, they may harbor important clues about the origins and mechanisms that helped create our planet Earth, and the processes that supported the rise of life here," he said.

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[cadbrowser]

On a larger scale, a similar process could have been involved in the making of our own moon, as well as other planetary satellites.

I thought the prevailing theory for the formation of Earth's Moon was the Giant Impact Hypothesis. Did I miss something regarding that?

[Borgholio]

I thought the prevailing theory for the formation of Earth's Moon was the Giant Impact Hypothesis. Did I miss something regarding that?

That's still the best theory for the matter, since if the moon consolidated alongside the Earth it would have a different mass and mineral composition.

[Formless]

I thought the prevailing theory for the formation of Earth's Moon was the Giant Impact Hypothesis. Did I miss something regarding that?

That is the best theory, but its only half of the story. The impact is how the materials that formed the moon got into orbit. But they didn't get into orbit as a fully formed orb. They had to re-coalesce into the moon. That's where this mechanism comes into the picture. Its pretty much like planetary formation, but on a slightly smaller scale.

[Ziggy Stardust]

I thought the prevailing theory for the formation of Earth's Moon was the Giant Impact Hypothesis. Did I miss something regarding that?

This mechanism is technically part of the Giant Impact Hypothesis. The Hypothesis doesn't state that something clipped off a Moon-sized chunk of Earth that just started to orbit us. It posits that there was a massive impact that resulted in a large ejection of debris into inner orbit, which would form a non-uniformly distributed "ring" of debris. In fact, there would likely be one (or possibly several) "clumps" in the ring. These "clumps" would then essentially accumulate into the Moon as we know it. (This is sort of dumbed down, but I think it's the most accurate way I can describe it in layman's language)

[Eternal_Freedom]

That's actually a pretty good description.

Sigh, this article half-makes me wish I was a student again, just so I could laugh at my Professor having to read this and say tomorrow "right, forget what I said last week about xyz solar system formation concept this is how it works now!" Which is word-for-word what he said after Kepler discovered a huge number of large gas giants close in to stars where the previous model had said they couldn't exist.

[Iroscato]

It can't just be me that's noticing how often we're making REALLY FUCKING COOL discoveries lately about space. I'm also of the opinion that the public's interest in space travel has been re-ignited in the last decade or so. It feels great being able to sit back and watch all of this unfolding!

[cadbrowser]

I thought the prevailing theory for the formation of Earth's Moon was the Giant Impact Hypothesis. Did I miss something regarding that?

This mechanism is technically part of the Giant Impact Hypothesis. The Hypothesis doesn't state that something clipped off a Moon-sized chunk of Earth that just started to orbit us. It posits that there was a massive impact that resulted in a large ejection of debris into inner orbit, which would form a non-uniformly distributed "ring" of debris. In fact, there would likely be one (or possibly several) "clumps" in the ring. These "clumps" would then essentially accumulate into the Moon as we know it. (This is sort of dumbed down, but I think it's the most accurate way I can describe it in layman's language)

I feel like an idiot now. I didn't think about the re-coalesce aspect of GIH. I guess it was the way they worded it in the article that confused me.

Thanks for the clarification. I went back and reread about it.

[Eternal_Freedom]

It can't just be me that's noticing how often we're making REALLY FUCKING COOL discoveries lately about space. I'm also of the opinion that the public's interest in space travel has been re-ignited in the last decade or so. It feels great being able to sit back and watch all of this unfolding!

It's not just you. As for the public interest part, well, Astronomy has become the default "cool science" it seems. Most likely because unlike nearly all other fields of science you can (and often do) have amatuers make significant contributions. Plus it's a lot easier to set up a couple of telescopes for a public event than, say, a particle accelerator. And telescopes are a lot easier for kids to understand too.

[Borgholio]

Plus it's a lot easier to set up a couple of telescopes for a public event than, say, a particle accelerator

Very true, but who here wouldn't want to visit LHC and watch that thing smash a few billion atoms?

[Eternal_Freedom]

Very true. However, going down to the local museum to see a few scopes is a lot cheaper and easier to do as a day-trip

[Borgholio]

Very true. However, going down to the local museum to see a few scopes is a lot cheaper and easier to do as a day-trip

Indeed. I actually have always enjoyed going to the Griffith Observatory and playing with exhibits. They have actual telescope feeds you can play with, periscopes, etc...

Oh and a seismometer. At the bottom of a small flight of stairs. Guess what we used to do as kids? Yeah...