Science Tidbits 3

[Lupine]

^Maybe it has something to do with the movement of the spacecraft itself.

[RJDiogenes]

Maybe. I've been picking apart the layers in Photoshop and it's kind of odd. The spots continue to glow after the floor of the crater is in shadow-- in fact, after the crater has passed the terminator. It's giving the impression of something three-dimensional that is actually taller than the rim of the crater. If that's the case, the only reason I can think of for it to suddenly spring into view like that is if it is only shiny on one side, and dull on the other side and the top. And both spots behave pretty much the same way. The brightest dot is right in the center of the crater, so it might represent that central peak that you get in some craters.

But it's reminding me of 2001 a bit.

[RJDiogenes]

Dawn successfully entered Ceres orbit yesterday.

Or would that be Ceresian orbit?

Anyway, the bad news is that it apparently won't be able to start sending pictures until April 23rd.

[Lupine]

I was going to post about that yesterday but got overly busy with other stuff. Wonder why there's a delay with the pics?

[RJDiogenes]

The article I read just said that it was passing behind Ceres, but I find it hard to believe that it will be in a radio shadow for a month and a half.

[Lupine]

Maybe those bright spots really were crashed alien spaceships.

[RJDiogenes]

My mind cannot help but go there.

[RJDiogenes]

And here we have the best evidence yet for an ocean on Ganymede. And quite an ocean it is, too.

[Lupine]

I somehow missed this post.

I did see something on this on the Bad Astronomy website and there's also evidence of hydrothermal vents on Enceladus. This is looking like it might be the most common liquid water environment in the universe.

[RJDiogenes]

Ah, they have evidence that the Enceladian ocean is in contact with the seabed. That does sound promising. The problem that I've heard with the ocean on Ganymede is that it may exist between two layers of ice, so there's none of the thermal vent activity that would probably be necessary for life. The Europan ocean seems to be in contact with the seabed, too.

Funny how the article blames Mars' current condition on a catastrophic collision rather than gradual environmental erosion; I don't think I've heard that before.

This is looking like it might be the most common liquid water environment in the universe.

It's amazing. We think of Earth as a water world with our vast oceans that cover most of the planet-- and yet both the small moons Europa and Ganymede likely have oceans that are far vaster.

[Lupine]

If no life is ever found on these worlds, it would probably be a good idea to transplant some of Earth's hydrothermal life there. Even when the sun becomes a red giant and eventually dies, life could persist in these environments for eons.

[RJDiogenes]

I'll bet that there would be people who would object to that, even if these worlds are as sterile as a neutron. It's a great idea, though. It's also a cool story seed for a story set in deep time, when the sun has swelled up.

[Lupine]

Another case of "the solar system is weird! Round up the usual suspects!"
The problem I have with this argument is primarily that far too many theories over the years have revolved around Jupiter. "The Earth has water! Jupiter must have hurled comets at us!" Or "We haven't been wiped out my asteroid! Jupiter must have shielded us!" And while migrating Jupiter seems reasonable it does seem like just another in the line of Jupiter made us theories. I've always been a little skeptical about migrating planets as it's seems pretty certain that Earth has more or less maintained its position in the system. If Earth has generally stayed put, why not Jupiter?
But it is odd that our system does appear to be unusually sparse. I've wondered if there was once a Hot Jupiter in the inner solar system that prevented Super Earth's from forming. It's also possible that the size and mass estimates for many exo-planets may be wrong. This is a new science after all. Maybe the cloud where the sun formed just had limited materiel from which to build planets. There may be some other factor that we haven't even considered yet.
Who knows?

[RJDiogenes]

Yeah, same thing with the Moon. There are those who claim that life on Earth would not be possible without the Moon stabilizing our wobbles, giving us tides, and protecting us from impacts.

I think the reason we're finding a lot of compact Solar Systems is that those are the easiest to find. And we're finding Super-Earths and Super-Jupiters because they're easier to find. I think as technology improves, Asimov's Law of the Small will become evident.

[Lupine]

NASA is predicting finding evidence of life before 2025, which is only off my estimate by five years.