Galileo's Flyby of Almathea
An anonymous reader writes "The spectacular Galileo flybys of Jupiter, Europa and Io are largely credited with the discovery of frozen water ice and some of the earliest examples of non-solar (tidal) heating anywhere in our solar system. For the next 10 days, Galileo scientists are preparing for their next target: probing one of Jupiter's moons, Almathea, at the close-up range of 100 miles. Almathea is one of the most unusual moons in the solar system, because it gives off more heat than it receives from the Sun."
Spending all these resources investigation such distant objects in outer space when there is so much so close to us that we have yet to get a good view of. Walk before we run people!
Have you been stalked by Seth today?
Sorry, I needed that rant.
Cheers!
It's disappointing, sure, but even had the arial been fully deployed, we wouldn't have significantly greater resolution, and might not see substantially more detail of Europa's surface. Also, the change in mission priorities might (?) have meant fewer resources spent on magnetometric observations. Events don't seem to change frequently enough on Europa's surface that a few missing frames would have changed our view much.
(Contrast with Io! What if we'd missed that eruption?)
First, nothing begins if not opening
And that makes it "actually a star" how, exactly?
You pretty much just gave the definition for why it isn't a star.
I think at least Io was so volcanic and active because of the extreme "tidal waves" from Jupiter. The "waves" are, due to the huge gravitation of Jupiter, so strong they pull solid matter and this of course cause quite a bit of friction. And friction cause heat. Not really surprising, since such a small object as our Moon does funny things to our seas. :-)
IIRC Io being heated is part of an interaction with the other Jovian moons. What happens is that a moon generating tides also transfers energy to the moon, so that it moves away from the planet it orbits. This is what happens here on Earth.
With Io the interaction of the other large moons keeps in in orbit, so the energy shows up as vulcanism.