Slashdot Mirror
Saturn's New Moons Named
sebFlyte writes "The BBC is reporting that three new moons found orbiting Saturn at the end of last year have been named. 'Two moons detected in August have been given the names Methone and Pallene, while another found in October has been provisionally named Polydeuces.' Polydeuces is also reported as being a very strange object-- a trojan moon. It sits in a spot near a larger moon where the gravitational pull of the other moon (Dione here) and the planet cancel each other out."
That's no Trojan moon...
I hadn't ever really thought about Lagrange points before I read that article. They are both interesting and intuitive to me. That there is a spot between two gravitational bodies that creates a "dead" spot, around which an object can orbit in a tug of war. Neat stuff. I find that more interesting than what names they have chosen for the moons.
We are one consciousness experiencing itself subjectively. Back to you with the weather, Bob!
Yikes better update my anti-virus. Don't want to get infected by W32.Polydeuces.A@mm now.
News Reporters Make Tasty Polar Bear Treats!
I believe the way the Lagrange points work (from what I read) is that the object "in it" orbits the lagrange point by being tugged back and forth... it's not just "sitting there at some fixed distance relative to the 2 bodies.
We are one consciousness experiencing itself subjectively. Back to you with the weather, Bob!
The point between to celestial bodies (usually a planet and it's moon) where the gravity of one is equal to the gravity of the other is called the Lagrange point.
Usually closer to the smaller of the two bodies, this point is a common location of sci-fi space stations, as there is no need to use an orbit to keep the station from decaying back into the larger bodies atmosphere.
There are no gods but ourselves.
I was a bit surprised about the name Polydeuces, because he (the mythological character) had little to do with Troy. However, it turns out that there's another Trojan moon called Helene (now this makes sense!), and Polydeucues is Helene's brother.
Because 'planet' is a greek name meaning 'wanderer.' Thte planets were thought to be the gods. Therefor, they named them with those names. Western civilization is largely inherited from the Greeks and the Romans. We kept the names. Besides, why the hell would we call Jupiter Lugh or Woden? It'd be weird.
When asked why they had named the moon now after millenia of observation, one student from Saturn's top university said, "Why not, you know? I mean, like, we had named everything else of importance, dude. Even the unimportant places. So like this was all that was left."
No comment could be received from inhabitants of !3kd8dgh, since they don't speak Standard Galactic. Moreover, they laughably think they are the only inhabitanted planet in the system, and it's considered taboo to disabuse them of this ignorance.
Oh Saturn, I love your rings. They make you look so beautiful. I just love being around them for all this time.
...TROJAN MOON.
Oh moon, the way you circle around me makes my weather patterns get all disrupted. You are just the perfect little moon, I love you.
Oh Saturn, I think its time for some gravitational pull...
This post has been filtered for sanity.
In celestial mechanics, Lagrange points come up in the three-body problem, where you have two large bodies (eg Sun and planet, planet and large moon) and one small object (a Trojan asteroid, spacecraft, new Saturn moon).
Lagrange points are the five places relative to the two large objects, where the third object will be held at the same position - relative to those two objects - in its orbit. In other words, there will be a net force on the third object that will result in it accelerating around the largest object at the same rate as the second largest object.*
A Lagrange point is stable if an object near by the L point will tend to be pulled towards or orbit around that point if it's a bit off the exact point. The L point is unstable if the object tends to be pulled further away from it once it wanders a little away.
The L1 point (in between the two large bodies), L4 and L5 points (60 deg ahead and behind the orbiting large body) are stable, the L2 and L3 points are unstable. Many of our solar observing spacecraft get sent to orbit the L1 point.
*(Center of mass discussion left out for relative simplicity)
Because these new moons are very small, and moreover they are very close to a large and bright planet like Saturn, that would outshine it in any telescope field of view.
We can see light from lightyears away. Moons in our solar system don't give off light, and reflect very little. It's the difference between looking around in full daylight, and trying to find a lost marble in the near total blackness of your bedroom.
How am I supposed to fit a pithy, relevant quote into 120 characters?
In the end, the International Astronomical Union. Which has not approved these names, as far as I can see. Until they do, it's just the Cassini team suggesting things.