This tiny speck is the 60th satellite found to circle Saturn. It was spotted by the Cassini spacecraft on May 30, 2007.

NASA / JPL / Space Science Institute

Here's a question a few of us have been wondering: when do discoveries stop becoming news? We once dutifully reported every extrasolar planet discovery as it was made. After all, finding worlds beyond our solar system is the stuff of science-fiction dreams. But then the number of exoplanets crossed 50, then 100, then 200, and is now at 246. A similar argument can be made for Martian and lunar meteorites. At some point — who knows exactly when — they stopped becoming "news."

Now NASA is reporting that Cassini spotted another moon around Saturn. That brings Saturn's family of satellites to 60. It currently has a temporary designation, S/2007 S4, but it will most likely earn one of those hard-to-pronounce names that all the new Saturnian satellites receive. If you want to see it move, NASA posted a cool animation showing the discovery.

The find, located inside the ring plane, doesn't place Saturn higher in the standings; Jupiter is still king with 63 satellites. But I suspect that won't last for long. Cassini is on patrol and there isn't a spacecraft in the hunt around Jupiter.

We've compiled the long list of moons for all the planets (and dwarf planets). Check it out, but see how many of them you know (or can pronounce) before clicking on the link.

So do you think this discovery is newsworthy? When will satellite discoveries become boring (if they aren't already)? Let us know what you think below.


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Justin Skywatcher

July 24, 2007 at 4:14 pm

Yes, I think new moons, extra-solar planets and asteroids are news. Perhaps not headline news, but they are worhty of mention

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July 24, 2007 at 7:02 pm

Yes! I love hearing about nifty new things in space.

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July 24, 2007 at 9:54 pm

Yes, they are. Also, I am glad that they are naming them and not just using the numbers. If you look at a table of data, or a chart of the orbts of the objects in the Jupiter system or the Saturnian system, you will find hard science and also wonder and magic (in a metphorical sense). It is like looking at a map of Indonesia, or of the Aegean Islands of Greece. Each large island is familiar, but you also see the names and positions of the lesser islands, some mere rocks, but fascinating nevertheless.

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Gain Lee

July 25, 2007 at 3:26 am

I wonder, is it time for another classification debate?
We all have the moons we love and know ie. Ganymede, Titan, Triton etc....Are we due a set of major, minor , standard , dwarf moons?

And yes, new moons are news worthy. Otherwise I'd have to say 'I don't know' when a child asks me ' How many moon does Saturn have?'

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Paulo André

July 25, 2007 at 3:42 am

Of course they are worhty of mention, because it is new data. However these new moons are always small pieces of rock or ice, moving around Saturn, so, is natural that they are less interisting and fascinating than large moons like Titan, Rhea, Tethys, among others, but despite their size they are newsworthy...

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Frank R

July 25, 2007 at 4:20 am

At a count of sixty, new moons are still newsworthy in my book, in the sense that I will read two or three paragraphs about the discovery. But there is a point where new moons will cease to be newsworthy in much the same way that new "planets" in the Solar System have ceased to be newsworthy. No one bats an eye at a new KBO, never mind a hundred new main belt asteroids. These are 'minor planets' and the very name makes them un-newsworthy, but they were once counted among the planets. Some similar effect will hit when the moons of Jupiter, Saturn, etc. hit a hundred or maybe two hundred. No one will keep track except trivia fans at that level... So how do we distinguish "significant" news of moon discoveries from noise? What we need is a system for categorizing these objects based on mass (preferably) or diameter. At some point we have to deal with the huge number of ring "particles" in Saturn's rings which are, of course, tiny moonlets. Let's hope no one starts naming those!


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Steve Hallmark

July 25, 2007 at 7:46 am

A 'new' moon should meet the same test of newsworthiness as any other news. A new mini member of the asteroid belt would be a yawn. But a moon that is (a) discovered using a new method, (b) has a previously unobserved (or rarely observed) property, such as a liquid helium ocean, or (c) its discovery can be linked to a new way of looking at or understanding moons in a statistical sense (e.g., 'planets with rings have fewer mini moons than planets without rings of a similar size', would be newsworthy.

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July 25, 2007 at 2:24 pm

Saturn has billions or trillions of moons. That's because there is no lower limit on how small a moon can be. Each dust mote in the rings counts. Well, if it can be resolved, and tracked, perhaps. Earth has thousands. Some astronaut's glove, etc. (They're even tracked.)

I've seen 5 of Saturn's moons. I'm convinced that i'll never see this new one, except in Cassini data. I doubt that the HST could detect it. When the Cassini mission ends, does this rock stop being a moon?

Yet, this is news. Not as moon number sixty. This little rock has something to tell us about the Saturn ring system. What it has to say is the news.

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Daniel Johnson

July 27, 2007 at 8:07 am

When the professional astronomers were trying define what constitutes a planet--with their work resulting in the demotion of Pluto--another, similar problem occurred to me (and probably to thousands of others): How do we define a moon? There is no definition, and there needs to be. It is absurd to name every tiny chunk of rock as if it were in the same class as Ganymede or Titan.
So the news is this: we don't know what a moon is.

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Fabulous Johnny G.

July 27, 2007 at 2:10 pm

I certainly enjoy reading about new space discovery's. Just the other day I was reading in tuesdays edition of the GALACTIC TIMES where it said that of 13,567,847,903,431,002 known planets 18,239,980 invented the wheel the other day. Also, that there were 156,784,945 discovery's of fire with seven burnt fingers. I find that all extremely interesting...Don't you...???

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Jeff G

July 27, 2007 at 6:19 pm

Daniel's remark is quite thoughtful.

This object is 'only' 1.2 km wide. Yes if it hit something, it could ruin your day, but there must be dozens (or more) more out there. Maybe I should star up the International Moon and Extrasolar Planet Registry! Then I could charge money... visit Australia... New Zealand... buy Astro Physics!! What a great idea! 🙂

I wonder if any of the more massive moons in the solar system themselves have moons? Are they moons of moons? A rose by any other name...?

Anyway yes, yawn, these new events are worth mentioning. But perhaps as a monthly, or quarterly roundup unless the discovery is A) by an amateur or pro/am collaboration, or B) something noteworthy or unusual.

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Charles Tuttle

July 30, 2007 at 11:41 am

I believe news is no longer newsworthy when that information becomes commonplace and no longer captures the interest and or the imagination of the reader. I am still captivated by such stories of discovery, so keep the reports coming.

The story about Saturn’s new moon and the question about newsworthiness raise the following question for this reader: What differentiates a moon from ring debris, particularly if the moon’s orbit is within a planetary ring?

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Abu Zafar

July 30, 2007 at 9:32 pm

I think it is a news item and I am interested in it but there should be some lower size limit on moons also otherwise it will be a problem also for moon naming committees.

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Christine P.

August 1, 2007 at 2:40 pm

Steve Hallmark makes good points. I would add that if Saturn surpassed Jupiter as the planet with the most known moons, that would also be newsworthy. But just another random rock - not so much.

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