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New Moon System Around Uranus
An anonymous reader writes "Astronomers have discovered two of the smallest moons yet found around Uranus. The new moons, uncovered by NASA's Hubble Space Telescope, are about 8 to 10 miles across (12 to 16 km) -- about the size of San Francisco. The two moons are so faint they eluded detection by the Voyager 2 spacecraft, which discovered 10 small satellites when it flew by the gas giant planet in 1986. The newly detected moons are orbiting even closer to the planet than the five major Uranian satellites, which are several hundred miles wide. The two new satellites are the first inner moons of Uranus discovered from an Earth-based telescope in more than 50 years. "It's a testament to how much our Earth-based instruments have improved in 20 plus years that we can now see such faint objects 1.7 billion miles (2.8 billion km) away," says Mark Showalter, a senior research associate at Stanford University. 'The inner swarm of 13 satellites is unlike any other system of planetary moons,' says co-investigator Jack Lissauer. 'The larger moons must be gravitationally perturbing the smaller moons. The region is so crowded that these moons could be gravitationally unstable. So, we are trying to understand how the moons can coexist with each other.'"
"Moon System Around Uranus"? Why even bother thinking of something funny? :/
If these moons are gravitationally astatic, stochastic motion could account for their motion in this deterministic system. We all know how complication three-body motion is, so with the number of objects affected by various gravitational fields out there, it would be incredibly hard to predict any movement at all. I wish them good luck in trying to precisely "understand how the moons can coexist with each other".
Is it not possible that these moons are so unstable that they will have relatively short lifespans? Might they soon end up crashing into the planet's surface or interact together and get flung off out of the solar system?
Turkeyphant
...so eager to take Hubble down, when it's still contributing so much to astrophysics? The new space telescope isn't even ready for launch yet, and who knows if it will work at first go? I'd rather have Hubble as backup until the new one is working smoothly and flawlessly before even thinking about bringing it down. Capitalism and politics just don't mix well with science.
www.rexguo.com - Technologist + Designer
There are even moons associated with asteroids. So it seems that the definition of a moon is any natural satellite orbiting a body that orbits the Sun. (A second order planet as it were.)
Siggy Sig Sig? Where is the sig?
What they said was correct at one time. It is no longer correct.
It actually isn't all that hard to predict their motion. There's a new mathematical tool, the Parker-Sochacki solution to the Picard Iteration, that has made great strides in the ability to predict this.
What's even better, this solution method is incredibly easy, conceptually simple, ideal for initial value problems, yields exact functional solutions, involves simple algebra [yes, that's right: simple algebra solutions to almost any set of partial differential equations] and turns out doubling precision for every iteration.
Oh, yes: there is a version out for Maple, too.
The solution that it turns out is a MacLauren series [functionally equal to the Taylor Series] dependant on as many variables as you need. However, for this you'd have everything dependent on time.
Also, this method *has* been used to predict planetary, moon, and asteroid motion. It works.
[PS: That last link has code for you code monkeys]
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
Yes, there's nothing funny about Uranus. let's forget the childish humor and take a serious, scholarly look at Uranus. To many people it's just a giant cloud of gas where the sun doesn't shine, but those of us who are enthusiastic about Uranus know that it has many secrets.
Surprising as it may seem, we don't have all that many photographs of Uranus. Yes, the Pioneers sent back pictures of Uranus, lots of them. But there are very few images that are high enough resolution and quality to show the faint rings around Uranus. Perhaps the excitement around these new moons will give us the excuse we need to take another long, hard look at Uranus.
Even if you have no idea how to find Uranus, you can still appreciate its unusual configuration. Scientists still don't understand why Uranus is tilted sideways. Also, while we know what's near the surface, we still aren't sure of the exact chemical mixture deep inside Uranus. Are the moons stable, or are they spiraling into Uranus?
With so much to learn, we must hope that NASA will probe the depths of Uranus soon. Yes, there are many technical issues that will need to be resolved, and problems to be faced--but we put men on the moon, and I'm sure that given sufficient motivation, NASA's engineers can lick Uranus too.
Oh, and yes, the size comparisons are silly, but can you think of a more sensible unit of size than San Francisco for an object in the vicinity of Uranus?
GCHQ Quantum Insert installed. If only our tongues were made of glass, how much more careful we would be when we speak